TY  - JOUR
A1  - Verch, Ronald
A1  - Hirschmüller, Anja
A1  - Müller, Juliane
A1  - Baur, Heiner
A1  - Mayer, Frank
A1  - Müller, Steffen
T1  - Is in-toing gait physiological in children?
BT  - Results of a large cohort study in 5910 healthy (pre-) school children
JF  - Gait & posture
N2  - Research question: This study aimed to establish reference values in 1-14 year old healthy children and to implement FPA-percentile curves for daily clinical use. Methods: 5910 healthy children performed at least 3 repetitions of barefoot walking over an instrumented walkway using a pressure measurement platform. The FPA [degrees] was extracted and analyzed by age and gender (mean +/- standard deviation; median with percentiles, MANOVA (age, gender) and Wilcoxon-Signed-Rank test for intra-individual side differences (alpha = 0.05). Results: FPA maximum was observed in 2-year-old children and diminished significant until the age of 4 to moderate out-toeing. For ages 5-14, no statistically significant differences in FPA values were present (p > 0.05). MANOVA confirmed age (p < 0.001) and gender (p < 0.001) as significant FPA influencing factors, without combined effect (p > 0.05). In every age group, right feet showed significantly greater out-toeing (p < 0.05). Significance: Percentile values indicate a wide FPA range in children. FPA development in young children shows a spontaneous shift towards moderate external rotation (age 2-4), whereby in-toeing <= 1-5 degrees can be present, but can return to normal. Bilateral in-toeing after the age of four and unilateral in-toeing after the age of seven should be monitored.
KW  - Foot progression angle
KW  - Children
KW  - In-toeing
KW  - Out-toeing
KW  - Gait
Y1  - 2018
U6  - https://doi.org/10.1016/j.gaitpost.2018.08.019
SN  - 0966-6362
SN  - 1879-2219
VL  - 66
SP  - 70
EP  - 75
PB  - Elsevier
CY  - Clare
ER  - 
TY  - JOUR
A1  - Eichler, Sarah
A1  - Rabe, Sophie
A1  - Salzwedel, Annett
A1  - Mueller, Steffen
A1  - Stoll, Josefine
A1  - Tilgner, Nina
A1  - John, Michael
A1  - Wegscheider, Karl
A1  - Mayer, Frank
A1  - Völler, Heinz
T1  - Effectiveness of an interactive telerehabilitation system with home-based exercise training in patients after total hip or knee replacement: study protocol for a multicenter, superiority, no-blinded randomized controlled trial
JF  - Trials
N2  - Background: Total hip or knee replacement is one of the most frequently performed surgical procedures. Physical rehabilitation following total hip or knee replacement is an essential part of the therapy to improve functional outcomes and quality of life. After discharge from inpatient rehabilitation, a subsequent postoperative exercise therapy is needed to maintain functional mobility. Telerehabilitation may be a potential innovative treatment approach. We aim to investigate the superiority of an interactive telerehabilitation intervention for patients after total hip or knee replacement, in comparison to usual care, regarding physical performance, functional mobility, quality of life and pain. Methods/design: This is an open, randomized controlled, multicenter superiority study with two prospective arms. One hundred and ten eligible and consenting participants with total knee or hip replacement will be recruited at admission to subsequent inpatient rehabilitation. After comprehensive, 3-week, inpatient rehabilitation, the intervention group performs a 3-month, interactive, home-based exercise training with a telerehabilitation system. For this purpose, the physiotherapist creates an individual training plan out of 38 different strength and balance exercises which were implemented in the system. Data about the quality and frequency of training are transmitted to the physiotherapist for further adjustment. Communication between patient and physiotherapist is possible with the system. The control group receives voluntary, usual aftercare programs. Baseline assessments are investigated after discharge from rehabilitation; final assessments 3 months later. The primary outcome is the difference in improvement between intervention and control group in 6-minute walk distance after 3 months. Secondary outcomes include differences in the Timed Up and Go Test, the Five-Times-Sit-to-Stand Test, the Stair Ascend Test, the Short-Form 36, the Western Ontario and McMaster Universities Osteoarthritis Index, the International Physical Activity Questionnaire, and postural control as well as gait and kinematic parameters of the lower limbs. Baseline-adjusted analysis of covariance models will be used to test for group differences in the primary and secondary endpoints. Discussion: We expect the intervention group to benefit from the interactive, home-based exercise training in many respects represented by the study endpoints. If successful, this approach could be used to enhance the access to aftercare programs, especially in structurally weak areas.
KW  - Telerehabilitation
KW  - Home-based
KW  - Total hip replacement
KW  - Total knee replacement
KW  - Exercise therapy
KW  - Aftercare
Y1  - 2017
U6  - https://doi.org/10.1186/s13063-017-2173-3
SN  - 1745-6215
VL  - 18
PB  - BioMed Central
CY  - London
ER  - 
TY  - JOUR
A1  - Wochatz, Monique
A1  - Engel, Tilman
A1  - Müller, Steffen
A1  - Mayer, Frank
T1  - Alterations in scapular kinematics and scapular muscle activity after fatiguing shoulder flexion and extension movements
JF  - Medicine and science in sports and exercise : MSSE
N2  - Repetitive overhead motions in combination with heavy loading were identified as risk factors for the development of shoulder pain. However, the underlying mechanism is not fully understood. Altered scapular kinematics as a result of muscle fatigue is suspected to be a contributor. PURPOSE: To determine scapular kinematics and scapular muscle activity at the beginning and end of constant shoulder flexion and extension loading in asymptomatic individuals. METHODS: Eleven asymptomatic adults (28±4yrs; 1.74±0.13m; 74±16kg) underwent maximum isokinetic loading of shoulder flexion (FLX) and extension (EXT) in the sagittal plane (ROM: 20- 180°; concentric mode; 180°/s) until individual peak torque was reduced by 50%. Simultaneously 3D scapular kinematics were assessed with a motion capture system and scapular muscle activity with a 3-lead sEMG of upper and lower trapezius (UT, LT) and serratus anterior (SA). Scapular position angles were calculated for every 20° increment between 20-120° humerothoracic positions. Muscle activity was quantified by amplitudes (RMS) of the total ROM. Descriptive analyses (mean±SD) of kinematics and muscle activity at begin (taskB) and end (taskE) of the loading task was followed by ANOVA and paired t-tests. RESULTS: At taskB activity ranged from 589±343mV to 605±250mV during FLX and from 105±41mV to 164±73mV during EXT across muscles. At taskE activity ranged from 594±304mV to 875±276mV during FLX and from 97±33mV to 147±57mV during EXT. Differences with increased muscle activity were seen for LT and UT during FLX (meandiff= 141±113mV for LT, p<0.01; 191±153mV for UT, p<0.01). Scapula position angles continuously increased in upward rotation, posterior tilt and external rotation during FLX and reversed during EXT both at taskB and taskE. At taskE scapula showed greater external rotation (meandiff= 3.6±3.7°, p<0.05) during FLX and decreased upward rotation (meandiff= 1.9±2.3°, p<0.05) and posterior tilt (meandiff= 1.0±2.1°, p<0.05) during EXT across humeral positions. CONCLUSIONS: Force reduction in consequence of fatiguing shoulder loading results in increased scapular muscle activity and minor alterations in scapula motion. Whether even small changes have a clinical impact by creating unfavorable subacromial conditions potentially initiating pain remains unclear.
Y1  - 2020
U6  - https://doi.org/10.1249/01.mss.0000676540.02017.2c
SN  - 0195-9131
SN  - 1530-0315
VL  - 52
IS  - 17
SP  - 274
EP  - 274
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Busch, Aglaja
A1  - Blasimann, Angela
A1  - Mayer, Frank
A1  - Baur, Heiner
T1  - Alterations in sensorimotor function after ACL reconstruction during active joint position sense testing. A systematic review
JF  - PLOS ONE
N2  - Background
The anterior cruciate ligament (ACL) rupture can lead to impaired knee function. Reconstruction decreases the mechanical instability but might not have an impact on sensorimotor alterations.

Objective
Evaluation of the sensorimotor function measured with the active joint position sense (JPS) test in anterior cruciate ligament (ACL) reconstructed patients compared to the contralateral side and a healthy control group.

Methods
The databases MEDLINE, CINAHL, EMBASE, PEDro, Cochrane Library and SPORTDiscus were systematically searched from origin until April 2020. Studies published in English, German, French, Spanish or Italian language were included. Evaluation of the sensorimotor performance was restricted to the active joint position sense test in ACL reconstructed participants or healthy controls. The Preferred Items for Systematic Reviews and Meta-Analyses guidelines were followed. Study quality was evaluated using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Data was descriptively synthesized.

Results
Ten studies were included after application of the selective criteria. Higher angular deviation, reaching significant difference (p < 0.001) in one study, was shown up to three months after surgery in the affected limb. Six months post-operative significantly less error (p < 0.01) was found in the reconstructed leg compared to the contralateral side and healthy controls. One or more years after ACL reconstruction significant differences were inconsistent along the studies.

Conclusions
Altered sensorimotor function was present after ACL reconstruction. Due to inconsistencies and small magnitudes, clinical relevance might be questionable. JPS testing can be performed in acute injured persons and prospective studies could enhance knowledge of sensorimotor function throughout the rehabilitative processes.
KW  - Body limbs
KW  - Knees
KW  - Sensory perception
KW  - Anterior cruciate ligament reconstruction
KW  - Legs
KW  - Tendons
KW  - Surgical and invasive medical procedures
KW  - Systematic reviews
Y1  - 2021
U6  - https://doi.org/10.1371/journal.pone.0253503
SN  - 1932-6203
VL  - 16
IS  - 6
PB  - PLOS
CY  - San Francisco
ER  - 
TY  - GEN
A1  - Molnar, Marco
A1  - Kok, Manor
A1  - Engel, Tilman
A1  - Kaplic, Hannes
A1  - Mayer, Frank
A1  - Seel, Thomas
T1  - A method for lower back motion assessment using wearable 6D inertial sensors
T2  - 21st International Conference on Information Fusion (FUSION)
N2  - Low back pain (LBP) is a leading cause of activity limitation. Objective assessment of the spinal motion plays a key role in diagnosis and treatment of LBP. We propose a method that facilitates clinical assessment of lower back motions by means of a wireless inertial sensor network. The sensor units are attached to the right and left side of the lumbar region, the pelvis and the thighs, respectively. Since magnetometers are known to be unreliable in indoor environments, we use only 3D accelerometer and 3D gyroscope readings. Compensation of integration drift in the horizontal plane is achieved by estimating the gyroscope biases from automatically detected initial rest phases. For the estimation of sensor orientations, both a smoothing algorithm and a filtering algorithm are presented. From these orientations, we determine three-dimensional joint angles between the thighs and the pelvis and between the pelvis and the lumbar region. We compare the orientations and joint angles to measurements of an optical motion tracking system that tracks each skin-mounted sensor by means of reflective markers. Eight subjects perform a neutral initial pose, then flexion/extension, lateral flexion, and rotation of the trunk. The root mean square deviation between inertial and optical angles is about one degree for angles in the frontal and sagittal plane and about two degrees for angles in the transverse plane (both values averaged over all trials). We choose five features that characterize the initial pose and the three motions. Interindividual differences of all features are found to be clearly larger than the observed measurement deviations. These results indicate that the proposed inertial sensor-based method is a promising tool for lower back motion assessment.
KW  - Inertial measurement units
KW  - joint angle estimation
KW  - human motion analysis
KW  - low back pain
KW  - back motion assessment
KW  - avoid magnetometers
KW  - validation against optical motion capture
KW  - drift correction
Y1  - 2018
SN  - 978-0-9964-5276-2
SP  - 799
EP  - 806
PB  - IEEE
CY  - New York
ER  - 
TY  - JOUR
A1  - Mueller, Juliane
A1  - Martinez-Valdes, Eduardo Andrés
A1  - Stoll, Josefine
A1  - Mueller, Steffen
A1  - Engel, Tilman
A1  - Mayer, Frank
T1  - Differences in neuromuscular activity of ankle stabilizing muscles during postural disturbances
BT  - a gender-specific analysis
JF  - Gait & posture
N2  - The purpose was to examine gender differences in ankle stabilizing muscle activation during postural disturbances. Seventeen participants (9 females: 27 +/- 2yrs., 1.69 +/- 0.1 m, 63 +/- 7 kg; 8 males: 29 +/- 2yrs., 1.81 +/- 0.1 m; 83 +/- 7 kg) were included in the study. After familiarization on a split-belt-treadmill, participants walked (1 m/s) while 15 right-sided perturbations were randomly applied 200 ms after initial heel contact. Muscle activity of M. tibialis anterior (TA), peroneus longus (PL) and gastrocnemius medialis (GM) was recorded during unperturbed and perturbed walking. The root mean square (RMS; [%]) was analyzed within 200 ms after perturbation. Co-activation was quantified as ratio of antagonist (GM)/agonist (TA) EMG-RMS during unperturbed and perturbed walking. Time to onset was calculated (ms). Data were analyzed descriptively (mean +/- SD) followed by three-way-ANOVA (gender/condition/muscle; alpha= 0.05). Perturbed walking elicited higher EMG activity compared to normal walking for TA and PL in both genders (p < 0.000). RMS amplitude gender comparisons revealed an interaction between gender and condition (F = 4.6, p = 0.049) and, a triple interaction among gender, condition and muscle (F = 4.7, p = 0.02). Women presented significantly higher EMG-RMS [%] PL amplitude than men during perturbed walking (mean difference = 209.6%, 95% confidence interval = -367.0 to -52.2%, p < 0.000). Co-activation showed significant lower values for perturbed compared to normal walking (p < 0.000), without significant gender differences for both walking conditions. GM activated significantly earlier than TA and PL (p < 0.01) without significant differences between the muscle activation onsets of men and women (p = 0.7). The results reflect that activation strategies of the ankle encompassing muscles differ between genders. In provoked stumbling, higher PL EMG activity in women compared to men is present. Future studies should aim to elucidate if this specific behavior has any relationship with ankle injury occurrence between genders.
KW  - Lower extremity
KW  - EMG
KW  - Perturbation
KW  - Split-belt treadmill
KW  - Ankle
Y1  - 2018
U6  - https://doi.org/10.1016/j.gaitpost.2018.01.023
SN  - 0966-6362
SN  - 1879-2219
VL  - 61
SP  - 226
EP  - 231
PB  - Elsevier
CY  - Clare
ER  - 
TY  - GEN
A1  - Baur, Heiner
A1  - Hirschmüller, Anja
A1  - Jahn, Michael
A1  - Müller, Steffen
A1  - Mayer, Frank
T1  - Therapeutic efficiency and biomechanical effects of sport insoles in female runners
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 624 
KW  - polyurethane foam
KW  - overuse injury
KW  - biomechanical effect
KW  - female runner
KW  - injury symptom
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-435525
SN  - 1866-8364
IS  - 624
ER  - 
TY  - JOUR
A1  - Quarmby, Andrew James
A1  - Khajooei, Mina
A1  - Engel, Tilman
A1  - Kaplick, Hannes
A1  - Mayer, Frank
T1  - The feasibility of a split-belt instrumented treadmill running protocol with perturbations
JF  - Journal of biomechanics
N2  - Unexpected perturbations during locomotion can occur during daily life or sports performance. Adequate compensation for such perturbations is crucial in maintaining effective postural control. Studies utilising instrumented treadmills have previously validated perturbed walking protocols, however responses to perturbed running protocols remain less investigated. Therefore, the purpose of this study was to investigate the feasibility of a new instrumented treadmill-perturbed running protocol. <br /> Fifteen participants (age = 2 8 +/- 3 years; height = 172 +/- 9 cm; weight = 69 +/- 10 kg; 60% female) completed an 8-minute running protocol at baseline velocity of 2.5 m/s (9 km/h), whilst 15 one-sided belt perturbations were applied (pre-set perturbation characteristics: 150 ms delay (post-heel contact); 2.0 m/s amplitude; 100 ms duration). Perturbation characteristics and EMG responses were recorded. Bland-Altman analysis (BLA) was employed (bias +/- limits of agreement (LOA; bias +/- 1.96*SD)) and intra-individual variability of repeated perturbations was assessed via Coefficients of Variation (CV) (mean +/- SD). <br /> On average, 9.4 +/- 2.2 of 15 intended perturbations were successful. Perturbation delay was 143 +/- 10 ms, amplitude was 1.7 +/- 0.2 m/s and duration was 69 +/- 10 ms. BLA showed -7 +/- 13 ms for delay, -0.3 +/- 0.1 m/s for amplitude and -30 +/- 10 ms for duration. CV showed variability of 19 +/- 4.5% for delay, 58 +/- 12% for amplitude and 30 +/- 7% for duration. EMG RMS amplitudes of the legs and trunk ranged from 113 +/- 25% to 332 +/- 305% when compared to unperturbed gait. This study showed that the application of sudden perturbations during running can be achieved, though with increased variability across individuals. The perturbations with the above characteristics appear to have elicited a neuromuscular response during running.
KW  - Lower-extremity perturbations
KW  - Split-belt treadmill
KW  - Running
KW  - Stumbling
KW  - EMC
Y1  - 2020
U6  - https://doi.org/10.1016/j.jbiomech.2019.109493
SN  - 0021-9290
SN  - 1873-2380
VL  - 98
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - GEN
A1  - Khajooei, Mina
A1  - Lin, Chiao-I
A1  - Steffan, Müller
A1  - Mayer, Frank
T1  - Effect of Instability in Legpress Testing on Strength & Muscle Activity in Functional Ankle Instability
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2018
U6  - https://doi.org/:10.1249/01.mss.0000537073.01736.db
SN  - 0195-9131
SN  - 1530-0315
VL  - 50
IS  - 5S
SP  - 602
EP  - 602
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - GEN
A1  - Martinez-Valdes, Eduardo
A1  - Negro, Francesco
A1  - Laine, Christopher M.
A1  - Falla, Deborah L.
A1  - Mayer, Frank
A1  - Farina, Dario
T1  - Identifying motor units in longitudinal studies with high-density surface electromyography
T2  - Converging clinical and engineering research on neurorehabilitation II
N2  - We investigated the possibility to identify motor units (MUs) with high-density surface electromyography (HDEMG) over experimental sessions in different days. 10 subjects performed submaximal knee extensions across three sessions in three days separated by one week, while EMG was recorded from the vastus medialis muscle with high-density electrode grids. The shapes of the MU action potentials (MUAPs) over multiple channels extracted from HDEMG decomposition were matched across sessions by cross-correlation. Forty and twenty percent of the MUs decomposed could be tracked across two and three sessions, respectively (average cross correlation 0.85 +/- 0.04). The estimated properties of the matched motor units were similar across the sessions. For example, mean discharge rate and recruitment thresholds were measured with an intra-class correlation coefficient (ICCs) > 0.80. These results strongly suggest that the same MUs were indeed identified across sessions. This possibility will allow monitoring changes in MU properties following interventions or during the progression of neuromuscular disorders.
Y1  - 2016
SN  - 978-3-319-46669-9
SN  - 978-3-319-46668-2
U6  - https://doi.org/10.1007/978-3-319-46669-9_27
SN  - 2195-3562
VL  - 15
SP  - 147
EP  - 151
PB  - Springer
CY  - Cham
ER  - 
TY  - JOUR
A1  - Müller, Juliane
A1  - Müller, Steffen
A1  - Stoll, Josefine
A1  - Rector, Michael V.
A1  - Baur, Heiner
A1  - Mayer, Frank
T1  - Influence of Load on Three-Dimensional Segmental Trunk Kinematics in One-Handed Lifting: A Pilot Study
JF  - Journal of applied biomechanics
N2  - Stability of the trunk is relevant in determining trunk response to different loading in everyday tasks initiated by the limbs. Descriptions of the trunk’s mechanical movement patterns in response to different loads while lifting objects are still under debate. Hence, the aim of this study was to analyze the influence of weight on 3-dimensional segmental motion of the trunk during 1-handed lifting. Ten asymptomatic subjects were included (29 ± 3 y; 1.79 ± 0.09 m; 75 ± 14 kg). Subjects lifted 3× a light and heavy load from the ground up onto a table. Three-dimensional segmental trunk motion was measured (12 markers; 3 segments: upper thoracic area [UTA], lower thoracic area [LTA], lumbar area [LA]). Outcomes were total motion amplitudes (ROM;[°]) for anterior flexion, lateral flexion, and rotation of each segment. The highest ROM was observed in the LTA segment (anterior flexion), and the smallest ROM in the UTA segment (lateral flexion). ROM differed for all planes between the 3 segments for both tasks (P < .001). There were no differences in ROM between light and heavy loads (P > .05). No interaction effects (load × segment) were observed, as ROM did not reveal differences between loading tasks. Regardless of weight, the 3 segments did reflect differences, supporting the relevance of multisegmental analysis.
KW  - trunk motion
KW  - kinematic trunk model
KW  - everyday task
KW  - MiSpEx*
Y1  - 2016
U6  - https://doi.org/10.1123/jab.2015-0227
SN  - 1065-8483
SN  - 1543-2688
VL  - 32
SP  - 520
EP  - 525
PB  - Human Kinetics Publ.
CY  - Champaign
ER  - 
TY  - JOUR
A1  - Lin, Chiao-I
A1  - Khajooei, Mina
A1  - Engel, Tilman
A1  - Nair, Alexandra
A1  - Heikkila, Mika
A1  - Kaplick, Hannes
A1  - Mayer, Frank
T1  - The effect of chronic ankle instability on muscle activations in lower extremities
JF  - PLOS ONE / Public Library of Science
N2  - Background/Purpose

Muscular reflex responses of the lower extremities to sudden gait disturbances are related to postural stability and injury risk. Chronic ankle instability (CAI) has shown to affect activities related to the distal leg muscles while walking. Its effects on proximal muscle activities of the leg, both for the injured- (IN) and uninjured-side (NON), remain unclear. Therefore, the aim was to compare the difference of the motor control strategy in ipsilateral and contralateral proximal joints while unperturbed walking and perturbed walking between individuals with CAI and matched controls.
Materials and methods

In a cross-sectional study, 13 participants with unilateral CAI and 13 controls (CON) walked on a split-belt treadmill with and without random left- and right-sided perturbations. EMG amplitudes of muscles at lower extremities were analyzed 200 ms after perturbations, 200 ms before, and 100 ms after (Post100) heel contact while walking. Onset latencies were analyzed at heel contacts and after perturbations. Statistical significance was set at alpha≤0.05 and 95% confidence intervals were applied to determine group differences. Cohen’s d effect sizes were calculated to evaluate the extent of differences.
Results

Participants with CAI showed increased EMG amplitudes for NON-rectus abdominus at Post100 and shorter latencies for IN-gluteus maximus after heel contact compared to CON (p<0.05). Overall, leg muscles (rectus femoris, biceps femoris, and gluteus medius) activated earlier and less bilaterally (d = 0.30–0.88) and trunk muscles (bilateral rectus abdominus and NON-erector spinae) activated earlier and more for the CAI group than CON group (d = 0.33–1.09).
Conclusion

Unilateral CAI alters the pattern of the motor control strategy around proximal joints bilaterally. Neuromuscular training for the muscles, which alters motor control strategy because of CAI, could be taken into consideration when planning rehabilitation for CAI.
KW  - Ankles
KW  - Walking
KW  - Electromyography
KW  - Hip
KW  - Skeletal joints
KW  - Knees
KW  - Legs
KW  - Musculoskeletal injury
Y1  - 2020
U6  - https://doi.org/10.1371/journal.pone.0247581
SN  - 1932-6203
VL  - 16
IS  - 2
PB  - PLOS
CY  - San Francisco
ER  - 
TY  - JOUR
A1  - Khajooei, Mina
A1  - Lin, Chiao-I
A1  - Mayer, Frank
A1  - Mueller, Steffen
T1  - Muscle activity and strength in maximum isokinetic legpress testing with unstable footplates in active individuals
JF  - Isokinetics and exercise science : official journal of the European Isokinetic Society
N2  - BACKGROUND: Compensating unstable situations is an important functional capability to maintain joint stability, to compensate perturbations and to prevent (re-)injury. Therefore, reduced maximum strength and altered neuromuscular activity are expected by inducing instability to load test situations. Possible effects are not clear for induced instability during maximum legpress tests in healthy individuals. OBJECTIVE: To compare isokinetic legpress (LP) strength and lower-leg muscle activity using stable (S) and unstable (UN) footplates. METHODS: 16 males (28 +/- 4 yrs, 179 +/- 7 cm, 75 +/- 8 kg) performed five maximum LP in concentric (CON) and eccentric (ECC) mode. The maximum force (Fmax) and muscle activity were measured under conditions of S and UN footplates. The tested muscles comprised of the tibialis anterior (TA), peroneus longus (PL) and soleus (SOL) and their activity were quantified against the MVIC of each muscle respectively. RESULTS: The main finding revealed a significant reduction in Fmax under UN condition: 11.9 +/- 11.3% in CON and 23.5 +/- 47.8% in ECC (P < 0.05). Significant findings were also noted regarding the RMS derived values of the EMG of PL and TA. CONCLUSION: Unstable LP reduced force generation and increased the activity of PL and TA muscles which confirmed greater neuromuscular effort to compensate instability. This may have some implications for resistance testing and training coupled with an unstable base in the prevention and rehabilitation of injury to the neuromusculoskeletal system.
KW  - Tibialis anterior
KW  - peroneus longus
KW  - soleus
KW  - instability
Y1  - 2019
U6  - https://doi.org/10.3233/IES-182206
SN  - 0959-3020
SN  - 1878-5913
VL  - 27
IS  - 3
SP  - 177
EP  - 183
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schomöller, Anne
A1  - Schugardt, Monique
A1  - Kotsch, Peggy
A1  - Mayer, Frank
T1  - The effect of body composition on cycling power during an incremental test in young athletes
JF  - Journal of strength and conditioning research : the research journal of the NSCA / National Strength & Conditioning Association
N2  - Schomoller, A, Schugardt, M, Kotsch, P, and Mayer, F. The effect of body composition on cycling power during an incremental test in young athletes. J Strength Cond Res 35(11): 3225-3231, 2021-As body composition (BC) is a modifiable factor influencing sports performance, it is of interest for athletes and coaches to optimize BC to fulfill the specific physical demands of one sport discipline. The purpose of this study is to test the impact of body fat (BF) and fat-free mass (FFM) on aerobic performance in young athletes. Body composition parameters were evaluated among gender and age groups of young athletes undergoing their mandatory health examination. The maximal power (in Watts per kilogram body mass) of a stepwise incremental ergometer test was compared between 6 BC types: high BF, high FFM, high BF and high FFM, normal BC values, low BF, and low FFM. With increasing age (11-13 vs. 14-16 years) BF decreased and FFM increased in both genders. Both BC parameters, as well as body mass, correlated moderately with performance output (r = 0.36-0.6). Subjects with high BF or high FFM or both had significantly lower ergometer test results compared with those with low BF and FFM in all age and gender groups (p < 0.05). The finding that high levels of BF and FFM are detrimental for cycle power output is important to consider in disciplines that demand high levels of aerobic and anaerobic performance.
KW  - youth competitive sport
KW  - body fat
KW  - fat-free mass
KW  - cycling performance
Y1  - 2020
U6  - https://doi.org/10.1519/JSC.0000000000003271
SN  - 1064-8011
SN  - 1533-4287
VL  - 35
IS  - 11
SP  - 3225
EP  - 3231
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Henschke, Jakob
A1  - Stoll, Josefine
A1  - Kopinski, Stephan
A1  - Lu, Yu-Hsien
A1  - Mayer, Frank
T1  - The effect of a low volume trunk-stabilisation exercise protocol on biomechanical function and compliance
JF  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2020
U6  - https://doi.org/10.1249/01.mss.0000678760.27551.f6
SN  - 0195-9131
SN  - 1530-0315
VL  - 52
IS  - 17
SP  - 446
EP  - 447
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - CHAP
A1  - Engel, Tilman
A1  - Müller, Juliane
A1  - Müller, Steffen
A1  - Reschke, Antje
A1  - Kopinski, Stephan
A1  - Mayer, Frank
T1  - Validity and reliability of a new customised split-belt treadmill provoking unexpected walking perturbations
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2013
SN  - 0195-9131
SN  - 1530-0315
VL  - 45
IS  - 5
SP  - 462
EP  - 462
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - CHAP
A1  - Wochatz, Monique
A1  - Kopinski, Stephan
A1  - Engel, Tilman
A1  - Müller, Steffen
A1  - Mayer, Frank
T1  - Flexion-extension ratio of trunk peak torque measures and antagonistic activity in males and females
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2014
SN  - 0195-9131
SN  - 1530-0315
VL  - 46
IS  - 5
SP  - 148
EP  - 148
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - CHAP
A1  - Kopinski, Stephan
A1  - Engel, Tilman
A1  - Müller, Steffen
A1  - Mayer, Frank
T1  - Torque-EMG relationship of lower back muscles - a pilot study
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2013
SN  - 0195-9131
SN  - 1530-0315
VL  - 45
IS  - 5
SP  - 7
EP  - 8
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Mueller, Juliane
A1  - Engel, Tilman
A1  - Mueller, Steffen
A1  - Kopinski, Stephan
A1  - Baur, Heiner
A1  - Mayer, Frank
T1  - Neuromuscular response of the trunk to sudden gait disturbances: Forward vs. backward perturbation
JF  - Journal of electromyography and kinesiology
N2  - The study aimed to analyse neuromuscular activity of the trunk comparing four different perturbations during gait. Thirteen subjects (28 +/- 3 yrs) walked (1 m/s) on a split-belt treadmill, while 4 (belt) perturbations (F1, F2, B1, B2) were randomly applied. Perturbations differed, related to treadmill belt translation, in direction (forward (F)/backward (B)) and amplitude (20 m/s(2) (1)/40 m/s(2) (2)). Trunk muscle activity was assessed with a 12-lead-EMG. EMG-RMS [%] (0-200 ms after perturbation; normalized to RMS of normal gait) was analyzed for muscles and four trunk areas (ventral left/right; dorsal left/right). Ratio of ventral: dorsal muscles were calculated. Muscle onset [ms] was determined. Data analysis was conducted descriptively, followed by ANOVA (post hoc Tukey-Kramer (alpha = 0.05)). All perturbations lead to an increase in EMG-RMS (428 +/- 289%). F1 showed the lowest and F2 the highest increase for the flexors. B2 showed the highest increase for the extensors. Significant differences between perturbations could be observed for 6 muscles, as well as the 4 trunk areas. Ratio analysis revealed no significant differences (range 1.25 (B1) to 1.71 (F2) between stimuli. Muscle response time (ventral: 87.0 +/- 21.7 ms; dorsal: 88.4 +/- 17.0 ms) between stimuli was only significant (p = 0.005) for the dorsal muscles. Magnitude significantly influences neuromuscular trunk response patterns in healthy adults. Regardless of direction ventral muscles always revealed higher relative increase of activity while compensating the walking perturbations. (C) 2016 Elsevier Ltd. All rights reserved.
KW  - Stumbling
KW  - Gait perturbation
KW  - EMG
KW  - Core
KW  - MiSpEx*
Y1  - 2016
U6  - https://doi.org/10.1016/j.jelekin.2016.07.005
SN  - 1050-6411
SN  - 1873-5711
VL  - 30
SP  - 168
EP  - 176
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Engel, Tilman
A1  - Mueller, Juliane
A1  - Kopinski, Stephan
A1  - Reschke, Antje
A1  - Mueller, Steffen
A1  - Mayer, Frank
T1  - Unexpected walking perturbations: Reliability and validity of a new treadmill protocol to provoke muscular reflex activities at lower extremities and the trunk
JF  - Journal of biomechanics
N2  - Instrumented treadmills offer the potential to generate standardized walking perturbations, which are particularly rapid and powerful. However, technical requirements to release adequate perturbations regarding timing, duration and amplitude are demanding. This study investigated the test-retest reliability and validity of a new treadmill perturbation protocol releasing rapid and unexpected belt perturbations to provoke muscular reflex responses at lower extremities and the trunk. Fourteen healthy participants underwent two identical treadmill walking protocols, consisting of 10 superimposed one-sided belt perturbations (100 ms duration; 2 m/s amplitude), triggered by a plantar pressure insole 200 ms after heel contact. Delay, duration and amplitude of applied perturbations were recorded by 3D-motion capture. Muscular reflex responses (within 200 ms) were measured at lower extremities and the trunk (10-lead EMG). Data was analyzed descriptively (mean +/- SD). Reliability was analyzed using test-retest variability (TRV%) and limits of agreement (LoA, bias +/- 1.96*SD). Perturbation delay was 202 14 ms, duration was 102 +/- 4 ms and amplitude was 2.1 +/- 0.01 m/s. TRV for perturbation delay, duration and amplitude ranged from 5.0% to 5.7%. LoA reached 3 +/- 36 ms for delay, 2 +/- 13 ms for duration and 0.0 +/- 0.3 m/s for amplitude. EMG amplitudes following perturbations ranged between 106 +/- 97% and 909 +/- 979% of unperturbed gait and EMG latencies between 82 +/- 14 ms and 106 +/- 16 ms. Minor differences between preset and observed perturbation characteristics and results of test-retest analysis prove a high validity with excellent reliability of the setup. Therefore, the protocol tested can be recommended to provoke muscular reflex responses at lower extremities and the trunk in perturbed walking. (C) 2017 Elsevier Ltd. All rights reserved.
KW  - Perturbation
KW  - Stumbling
KW  - Gait
KW  - Treadmill
KW  - Reliability
KW  - MiSpEx
Y1  - 2017
U6  - https://doi.org/10.1016/j.jbiomech.2017.02.026
SN  - 0021-9290
SN  - 1873-2380
VL  - 55
SP  - 152
EP  - 155
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Müller, Juliane
A1  - Engel, Tilman
A1  - Kopinski, Stephan
A1  - Mayer, Frank
A1  - Müller, Steffen
T1  - Neuromuscular trunk activation patterns in back pain patients during one-handed lifting
JF  - World journal of orthopedics
N2  - AIM To analyze neuromuscular activity patterns of the trunk in healthy controls (H) and back pain patients (BPP) during one-handed lifting of light to heavy loads. METHODS RESULTS Seven subjects (3m/4f; 32 +/- 7 years; 171 +/- 7 cm; 65 +/- 11 kg) were assigned to BPP (pain grade >= 2) and 36 (13m/23f; 28 +/- 8 years; 174 +/- 10 cm; 71 +/- 12 kg) to H (pain grade <= 1). H and BPP did not differ significantly in anthropometrics (P > 0.05). All subjects were able to lift the light and middle loads, but 57% of BPP and 22% of H were not able to lift the heavy load (all women) chi(2) analysis revealed statistically significant differences in task failure between H vs BPP (P = 0.03). EMG-RMS ranged from 33% +/- 10%/30% +/- 9% (DL, 1 kg) to 356% +/- 148%/283% +/- 80% (VR, 20 kg) in H/BPP with no statistical difference between groups regardless of load (P > 0.05). However, the EMG-RMS of the VR was greatest in all lifting tasks for both groups and increased with heavier loads. CONCLUSION Heavier loading leads to an increase (2-to 3-fold) in trunk muscle activity with comparable patterns. Heavy loading (20 kg) leads to task failure, especially in women with back pain.
KW  - Lifting
KW  - Core
KW  - Trunk
KW  - EMG
KW  - MISPEX
Y1  - 2016
U6  - https://doi.org/10.5312/wjo.v8.i2.142
SN  - 2218-5836
VL  - 8
IS  - 2
SP  - 142
EP  - 148
PB  - Baishideng Publishing Group
CY  - Pleasanton
ER  - 
TY  - CHAP
A1  - Scharhag, Jürgen
A1  - Hotzkow, Kristin
A1  - Kopinski, Stephan
A1  - Barche, Martin
A1  - Mayer, Frank
T1  - Echocardiographic 3d speckle tracking values on cardiac wall motion in elite adult, adolescent and pediatric athletes
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2012
SN  - 0195-9131
VL  - 44
SP  - 241
EP  - 241
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Wochatz, Monique
A1  - Tilgner, Nina
A1  - Mueller, Steffen
A1  - Rabe, Sophie
A1  - Eichler, Sarah
A1  - John, Michael
A1  - Völler, Heinz
A1  - Mayer, Frank
T1  - Reliability and validity of the Kinect V2 for the assessment of lower extremity rehabilitation exercises
JF  - Gait & posture
N2  - Research question: The purpose of this study was to evaluate the test-retest reliability of lower extremity kinematics during squat, hip abduction and lunge exercises captured by the Kinect and to evaluate the agreement to a reference 3D camera-based motion system. Methods: Twenty-one healthy individuals performed five repetitions of each lower limb exercise on two different days. Movements were simultaneously assessed by the Kinect and the reference 3D motion system. Joint angles and positions of the lower limb were calculated for sagittal and frontal plane. For the inter-session reliability and the agreement between the two systems standard error of measurement (SEM), bias with limits of agreement (LoA) and Pearson Correlation Coefficient (r) were calculated. Results: Parameters indicated varying reliability for the assessed joint angles and positions and decreasing reliability with increasing task complexity. Across all exercises, measurement deviations were shown especially for small movement amplitudes. Variability was acceptable for joint angles and positions during the squat, partially acceptable during the hip abduction and predominately inacceptable during the lunge. The agreement between systems was characterized by systematic errors. Overestimations by the Kinect were apparent for hip flexion during the squat and hip abduction/adduction during the hip abduction exercise as well as for the knee positions during the lunge. Knee and hip flexion during hip abduction and lunge were underestimated by the Kinect. Significance: The Kinect system can reliably assess lower limb joint angles and positions during simple exercises. The validity of the system is however restricted. An application in the field of early orthopedic rehabilitation without further development of post-processing techniques seems so far limited.
KW  - Reproducibility
KW  - Agreement
KW  - Markerless motion capture system
KW  - Telerehabilitation
Y1  - 2018
U6  - https://doi.org/10.1016/j.gaitpost.2019.03.020
SN  - 0966-6362
SN  - 1879-2219
VL  - 70
SP  - 330
EP  - 335
PB  - Elsevier
CY  - Clare
ER  - 
TY  - JOUR
A1  - Wochatz, Monique
A1  - Rabe, Sophie
A1  - Wolter, Martin
A1  - Engel, Tilman
A1  - Mueller, Steffen
A1  - Mayer, Frank
T1  - Reproducibility of scapular muscle activity in isokinetic shoulder flexion and extension
JF  - Journal of electromyography and kinesiology
N2  - Repetitive overhead movements have been identified as a main risk factor to develop shoulder complaints with scapular muscle activity being altered. Reliable assessment of muscle activity is essential to differentiate between symptomatic and asymptomatic individuals. Therefore, the present study aimed to investigate the intra-and inter-session reliability of scapular muscle activity during maximal isokinetic shoulder flexion and extension. Eleven asymptomatic adults performed maximum effort isokinetic shoulder flexion and extension (concentric and eccentric at 60 degrees/s) in a test-retest design. Muscle activity of the upper and lower trapezius and serratus anterior was assessed by sEMG. Root Mean Square was calculated for whole ROM and single movement phases of absolute and normalized muscle activity. Absolute (Bland-Altman analysis (Bias, LoA), Minimal detectable change (MDC)) and relative reliability parameters (Intraclass correlation coefficient (ICC), coefficient of variation (CV)/test-retest variability (TRV)) were utilized for the evaluation of reproducibility. Intra-session reliability revealed ICCs between 0.56 and 0.98, averaged CVs of 18% and average MDCs of 81 mV. Inter-session reliability resulted in ICCs between 0.13 and 0.93, averaged TRVs of 21%, average MDCs of 15% and systematic and random error between -8 +/- 60% and 12 +/- 36%. Scapular muscle activity assessed in overhead movements can be measured reliably under maximum load conditions, though variability is dependent on the movement phase. Measurement variability does not exceed magnitudes of altered scapular muscle activities as reported in previous studies. Therefore, maximum load application is a promising approach for the evaluation of changes in scapular control related to pathologies. (C) 2017 Elsevier Ltd. All rights reserved.
Y1  - 2017
U6  - https://doi.org/10.1016/j.jelekin.2017.04.006
SN  - 1050-6411
SN  - 1873-5711
VL  - 34
SP  - 86
EP  - 92
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Wochatz, Monique
A1  - Rabe, Sophie
A1  - Wolter, Martin
A1  - Engel, Tilman
A1  - Mueller, Steffen
A1  - Mayer, Frank
T1  - Muscle activity of upper and lower trapezius and serratus anterior during unloaded and maximal loaded shoulder flexion and extension
JF  - International Biomechanics
N2  - Altered scapular muscle activity is mostly described under unloaded and submaximal loaded conditions in impingement patients. However, there is no clear evidence on muscle activity with respect to movement phases under maximum load in healthy subjects. Therefore, this study aimed to investigate scapular muscle activity under unloaded and maximum loaded isokinetic shoulder flexion and extension in regard to the movement phase. Fourteen adults performed unloaded (continuous passive motion [CPM]) as well as maximum loaded (concentric [CON], eccentric [ECC]) isokinetic shoulder flexion (Flex) and extension (Ext). Simultaneously, scapular muscle activity was measured by EMG. Root mean square was calculated for the whole ROM and four movement phases. Data were analyzed descriptively and by two-way repeated measures ANOVA. CPMFlex resulted in a linear increase of muscle activity for all muscles. Muscle activity during CONFlex and ECCFlex resulted in either constant activity levels or in an initial increase followed by a plateau in the second half of movement. CPMExt decreased with the progression of movement, whereas CONExt and ECCExt initially decreased and either levelled off or increased in the second half of movement. Scapular muscle activity of unloaded shoulder flexion and extension changed under maximum load showing increased activity levels and an altered pattern over the course of movement.
KW  - shoulder
KW  - scapular muscle activity
KW  - isokinetic testing
KW  - electromyography
Y1  - 2017
U6  - https://doi.org/https://doi.org/10.1080/23335432.2017.1364668
VL  - 4
IS  - 2
SP  - 68
EP  - 76
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Müller, Steffen
A1  - Baur, Heiner
A1  - Hirschmueller, Anja
A1  - Mayer, Frank
T1  - Validität des COP-Verlaufes zur Quantifizierung der funktionalen Gangentwicklung bei Kindern
N2  - Functional gait development in children is discussed controversially. Differentiated information about the roll- over process of the foot, represented by the "Center of Pressure" (COP), are still missing. The purpose of the study was the validation of the COP-path to quantify the functional gait development of children. Plantar pressure distribution was measured barefoot with an individual speed on a walkway (tartan) - in 255 children aged between 2 and 15 years. The medial and lateral area enclosed between the COP-path and the bisection of plantar angle (A(med), A(lat), Sigma: A(ml)) was calculated from plantar pressure data. Furthermore, the duration of the COP-path in the heel (COPtimeF), midfoot (COPtimeM) and forefoot (COPtimeV) was analysed. The load distribution under the medial and lateral forefoot was also calculated. The variation coefficient (VC) was calculated as a measure of interindividual variability. The medio-lateral divergency of the COP (Aml) initially decreases with advancing age (-20.2%), followed by a continuous increase (+27.2%). No changes in VC (A(med), A(lat), and A(ml)) appeared during age-related development. COPtimeM remains constant in all children over time. In contrast to COPtimeM, Cop(time)F decreases from youngest to oldest children (-31.0%), and COPtimeV increases (+41.7%). After initial descent up to 8 years of age, VC (COPtimeF, COPtimeM, COPtimeV) remains constant. The mediolateral load under the forefoot did not change. The COP-Path is able to characterise the functional gait development of children. VC values indicate high individual variability of gait pattern. In this context, age-based standard values should be critically discussed
Y1  - 2006
ER  - 
TY  - JOUR
A1  - Mugele, Hendrik
A1  - Plummer, Ashley
A1  - Baritello, Omar
A1  - Towe, Maggie
A1  - Brecht, Pia
A1  - Mayer, Frank
T1  - Accuracy of training recommendations based on a treadmill multistage incremental exercise test
JF  - PLOS ONE
N2  - Competitive runners will occasionally undergo exercise in a laboratory setting to obtain predictive and prescriptive information regarding their performance. The present research aimed to assess whether the physiological demands of lab-based treadmill running (TM) can simulate that of over-ground (OG) running using a commonly used protocol. Fifteen healthy volunteers with a weekly mileage of ≥ 20 km over the past 6 months and treadmill experience participated in this cross-sectional study. Two stepwise incremental tests until volitional exhaustion was performed in a fixed order within one week in an Outpatient Clinic research laboratory and outdoor athletic track. Running velocity (IATspeed), heart rate (IATHR) and lactate concentration at the individual anaerobic threshold (IATbLa) were primary endpoints. Additionally, distance covered (DIST), maximal heart rate (HRmax), maximal blood lactate concentration (bLamax) and rate of perceived exertion (RPE) at IATspeed were analyzed. IATspeed, DIST and HRmax were not statistically significantly different between conditions, whereas bLamax and RPE at IATspeed showed statistical significance (p < 0.05). Apart from RPE at IATspeed, IATspeed, DIST, HRmax and bLamax strongly correlate between conditions (r = 0.815–0.988). High reliability between conditions provides strong evidence to suggest that running on a treadmill are physiologically comparable to that of OG and that training recommendations and be made with assurance.
KW  - individual anaerobic threshold
KW  - lactate threshold
KW  - soccer players
KW  - performance
KW  - validity
KW  - reliability
KW  - runners
Y1  - 2018
U6  - https://doi.org/10.1371/journal.pone.0204696
SN  - 1932-6203
VL  - 13
IS  - 10
SP  - 1
EP  - 12
PB  - PLOS
CY  - San Francisco
ER  - 
TY  - JOUR
A1  - Diehl, Katharina
A1  - Mayer, Manfred
A1  - Mayer, Frank
A1  - Görig, Tatiana
A1  - Bock, Christina
A1  - Herr, Raphael M.
A1  - Schneider, Sven
T1  - Physical Activity Counseling by Primary Care Physicians: Attitudes, Knowledge, Implementation, and Perceived Success
JF  - Journal of physical activity and health
N2  - Background: In physical activity (PA) counseling, primary care physicians (PCPs) play a key role because they are in regular contact with large sections of the population and are important contact people in all health-related issues. However, little is known about their attitudes, knowledge, and perceived success, as well as about factors associated with the implementation of PA counseling. Methods: We collected data from 4074 PCPs including information on physician and practice characteristics, attitudes toward cardiovascular disease (CVD) prevention, and measures used during routine practice to prevent CVD. Here, we followed widely the established 5 A's strategy (Assess, Advise, Agree, Assist, Arrange). Results: The majority (87.2%) of PCPs rated their own level of competence in PA counseling as 'high,' while 52.3% rated their own capability to motivate patients to increase PA as 'not good.' Nine of ten PCPs routinely provided at least 1 measure of the modified 5 A's strategy, while 9.5% routinely used all 5 intervention strategies. Conclusions: The positive attitude toward PA counseling among PCPs should be supported by other stakeholders in the field of prevention and health promotion. An example would be the reimbursement of health counseling services by compulsory health insurance, which would enable PCPs to invest more time in individualized health promotion.
KW  - prevention
KW  - cardiovascular diseases
KW  - general practitioners
Y1  - 2015
U6  - https://doi.org/10.1123/jpah.2013-0273
SN  - 1543-3080
SN  - 1543-5474
VL  - 12
IS  - 2
SP  - 216
EP  - 223
PB  - Human Kinetics Publ.
CY  - Champaign
ER  - 
TY  - JOUR
A1  - Eichler, Sarah
A1  - Salzwedel, Annett
A1  - Rabe, Sophie
A1  - Mueller, Steffen
A1  - Mayer, Frank
A1  - Wochatz, Monique
A1  - Hadzic, Miralem
A1  - John, Michael
A1  - Wegscheider, Karl
A1  - Völler, Heinz
T1  - The Effectiveness of Telerehabilitation as a Supplement to Rehabilitation in Patients After Total Knee or Hip Replacement
BT  - Randomized Controlled Trial
JF  - JMIR Rehabilitation and Assistive Technologies
N2  - Background: Telerehabilitation can contribute to the maintenance of successful rehabilitation regardless of location and time. The aim of this study was to investigate a specific three-month interactive telerehabilitation routine regarding its effectiveness in assisting patients with physical functionality and with returning to work compared to typical aftercare.

Objective: The aim of the study was to investigate a specific three-month interactive telerehabilitation with regard to effectiveness in functioning and return to work compared to usual aftercare.

Methods: From August 2016 to December 2017, 111 patients (mean 54.9 years old; SD 6.8; 54.3% female) with hip or knee replacement were enrolled in the randomized controlled trial. At discharge from inpatient rehabilitation and after three months, their distance in the 6-minute walk test was assessed as the primary endpoint. Other functional parameters, including health related quality of life, pain, and time to return to work, were secondary endpoints.

Results: Patients in the intervention group performed telerehabilitation for an average of 55.0 minutes (SD 9.2) per week. Adherence was high, at over 75%, until the 7th week of the three-month intervention phase. Almost all the patients and therapists used the communication options. Both the intervention group (average difference 88.3 m; SD 57.7; P=.95) and the control group (average difference 79.6 m; SD 48.7; P=.95) increased their distance in the 6-minute-walk-test. Improvements in other functional parameters, as well as in quality of life and pain, were achieved in both groups. The higher proportion of working patients in the intervention group (64.6%; P=.01) versus the control group (46.2%) is of note.

Conclusions: The effect of the investigated telerehabilitation therapy in patients following knee or hip replacement was equivalent to the usual aftercare in terms of functional testing, quality of life, and pain. Since a significantly higher return-to-work rate could be achieved, this therapy might be a promising supplement to established aftercare.
KW  - telerehabilitation
KW  - home-based
KW  - total hip replacement
KW  - total knee replacement
KW  - exercise therapy
KW  - aftercare
KW  - rehabilitation
Y1  - 2019
U6  - https://doi.org/10.2196/14236
SN  - 2369-2529
VL  - 6
IS  - 2
PB  - jmir rehab
CY  - Toronto
ER  - 
TY  - JOUR
A1  - Müller, Juliane
A1  - Hadzic, Miralem
A1  - Mugele, Hendrik
A1  - Stoll, Josefine
A1  - Müller, Steffen
A1  - Mayer, Frank
T1  - Effect of high-intensity perturbations during core-specific sensorimotor exercises on trunk muscle activation
JF  - Journal of biomechanics
N2  - Core-specific sensorimotor exercises are proven to enhance neuromuscular activity of the trunk. However, the influence of high-intensity perturbations on training efficiency is unclear within this context. Sixteen participants (29 +/- 2 yrs; 175 +/- 8 cm; 69 +/- 13 kg) were prepared with a 12-lead bilateral trunk EMG. Warm-up on a dynamometer was followed by maximum voluntary isometric trunk (flex/ext) contraction (MVC). Next, participants performed four conditions for a one-legged stance with hip abduction on a stable surface (HA) repeated randomly on an unstable surface (HAP), on a stable surface with perturbation (HA + P), and on an unstable surface with perturbation (HAP + P). Afterwards, bird dog (BD) was performed under the same conditions (BD, BDP, BD + P, BDP + P). A foam pad under the foot (HA) or the knee (BD) was used as an unstable surface. Exercises were conducted on a moveable platform. Perturbations (ACC 50 m/sec(2);100 ms duration;10rep.) were randomly applied in the anterior-posterior direction. The root mean square (RMS) normalized to MVC (%) was calculated (whole movement cycle). Muscles were grouped into ventral right and left (VR;VL), and dorsal right and left (DR;DL). Ventral Dorsal and right-left ratios were calculated (two way repeated-measures ANOVA;alpha = 0,05). Amplitudes of all muscle groups in bird dog were higher compared to hip abduction (p <= 0.0001; Range: BD: 14 +/- 3% (BD;VR) to 53 +/- 4%; HA: 7 +/- 2% (HA;DR) to 16 +/- 4% (HA;DR)). EMG-RMS showed significant differences (p < 0.001) between conditions and muscle groups per exercise. Interaction effects were only significant for HA (p = 0.02). No significant differences were present in EMG ratios (p > 0.05). Additional high-intensity perturbations during core-specific sensorimotor exercises lead to increased neuromuscular activity and therefore higher exercise intensities. However, the beneficial effects on trunk function remain unclear. Nevertheless, BD is more suitable to address trunk muscles.
KW  - Split-belt treadmill
KW  - EMG
KW  - Core stability
KW  - MiSpEx
Y1  - 2017
U6  - https://doi.org/10.1016/j.jbiomech.2017.12.013
SN  - 0021-9290
SN  - 1873-2380
VL  - 70
SP  - 212
EP  - 218
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Risch, Lucie
A1  - Mayer, Frank
A1  - Cassel, Michael
T1  - Doppler flow response following running exercise differs between healthy and tendinopathic Achilles tendons
JF  - Frontiers in Physiology
N2  - Background: The relationship between exercise-induced intratendinous blood flow (IBF) and tendon pathology or training exposure is unclear.

Objective: This study investigates the acute effect of running exercise on sonographic detectable IBF in healthy and tendinopathic Achilles tendons (ATs) of runners and recreational participants.

Methods: 48 participants (43 ± 13 years, 176 ± 9 cm, 75 ± 11 kg) performed a standardized submaximal 30-min constant load treadmill run with Doppler ultrasound “Advanced dynamic flow” examinations before (Upre) and 5, 30, 60, and 120 min (U5-U120) afterward. Included were runners (>30 km/week) and recreational participants (<10 km/week) with healthy (Hrun, n = 10; Hrec, n = 15) or tendinopathic (Trun, n = 13; Trec, n = 10) ATs. IBF was assessed by counting number [n] of intratendinous vessels. IBF data are presented descriptively (%, median [minimum to maximum range] for baseline-IBF and IBF-difference post-exercise). Statistical differences for group and time point IBF and IBF changes were analyzed with Friedman and Kruskal-Wallis ANOVA (α = 0.05).

Results: At baseline, IBF was detected in 40% (3 [1–6]) of Hrun, in 53% (4 [1–5]) of Hrec, in 85% (3 [1–25]) of Trun, and 70% (10 [2–30]) of Trec. At U5 IBF responded to exercise in 30% (3 [−1–9]) of Hrun, in 53% (4 [−2–6]) of Hrec, in 70% (4 [−10–10]) of Trun, and in 80% (5 [1–10]) of Trec. While IBF in 80% of healthy responding ATs returned to baseline at U30, IBF remained elevated until U120 in 60% of tendinopathic ATs. Within groups, IBF changes from Upre-U120 were significant for Hrec (p < 0.01), Trun (p = 0.05), and Trec (p < 0.01). Between groups, IBF changes in consecutive examinations were not significantly different (p > 0.05) but IBF-level was significantly higher at all measurement time points in tendinopathic versus healthy ATs (p < 0.05).

Conclusion: Irrespective of training status and tendon pathology, running leads to an immediate increase of IBF in responding tendons. This increase occurs shortly in healthy and prolonged in tendinopathic ATs. Training exposure does not alter IBF occurrence, but IBF level is elevated in tendon pathology. While an immediate exercise-induced IBF increase is a physiological response, prolonged IBF is considered a pathological finding associated with Achilles tendinopathy.
KW  - neovascularization
KW  - tendinopathy
KW  - Doppler ultrasound
KW  - Advanced Dynamic Flow
KW  - athlete
KW  - sonography
Y1  - 2021
U6  - https://doi.org/10.3389/fphys.2021.650507
SN  - 1664-042X
VL  - 12
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Cassel, Michael
A1  - Stoll, Josefine
A1  - Schugardt, Monique
A1  - Mayer, Frank
T1  - Overuse and injury prevention
JF  - Elite youth cycling
Y1  - 2019
SN  - 978-1-315-11077-6
SN  - 978-1-138-08684-5
SP  - 141
EP  - 159
PB  - Routledge
CY  - London
ER  - 
TY  - JOUR
A1  - Risch, Lucie
A1  - Stoll, Josefine
A1  - Schomöller, Anne
A1  - Engel, Tilman
A1  - Mayer, Frank
A1  - Cassel, Michael
T1  - Intraindividual Doppler Flow Response to Exercise Differs Between Symptomatic and Asymptomatic Achilles Tendons
JF  - Frontiers in physiology
N2  - Objective: This study investigated intraindividual differences of intratendinous blood flow (IBF) in response to running exercise in participants with Achilles tendinopathy.

Design: This is a cross-sectional study.

Setting: The study was conducted at the University Outpatient Clinic.

Participants: Sonographic detectable intratendinous blood flow was examined in symptomatic and contralateral asymptomatic Achilles tendons of 19 participants (42 ± 13 years, 178 ± 10 cm, 76 ± 12 kg, VISA-A 75 ± 16) with clinically diagnosed unilateral Achilles tendinopathy and sonographic evident tendinosis.

Intervention: IBF was assessed using Doppler ultrasound “Advanced Dynamic Flow” before (Upre) and 5, 30, 60, and 120 min (U5–U120) after a standardized submaximal constant load run.

Main Outcome Measure: IBF was quantified by counting the number (n) of vessels in each tendon.

Results: At Upre, IBF was higher in symptomatic compared with asymptomatic tendons [mean 6.3 (95% CI: 2.8–9.9) and 1.7 (0.4–2.9), p < 0.01]. Overall, 63% of symptomatic and 47% of asymptomatic Achilles tendons responded to exercise, whereas 16 and 11% showed persisting IBF and 21 and 42% remained avascular throughout the investigation. At U5, IBF increased in both symptomatic and asymptomatic tendons [difference to baseline: 2.4 (0.3–4.5) and 0.9 (0.5–1.4), p = 0.05]. At U30 to U120, IBF was still increased in symptomatic but not in asymptomatic tendons [mean difference to baseline: 1.9 (0.8–2.9) and 0.1 (-0.9 to 1.2), p < 0.01].

Conclusion: Irrespective of pathology, 47–63% of Achilles tendons responded to exercise with an immediate acute physiological IBF increase by an average of one to two vessels (“responders”). A higher amount of baseline IBF (approximately five vessels) and a prolonged exercise-induced IBF response found in symptomatic ATs indicate a pain-associated altered intratendinous “neovascularization.”
KW  - achilles tendinopathy
KW  - tendinosis
KW  - neovascularization
KW  - ultrasound
KW  - advanced dynamic flow
KW  - sonography
Y1  - 2021
U6  - https://doi.org/10.3389/fphys.2021.617497
SN  - 1664-042X
VL  - 12
SP  - 1
EP  - 8
PB  - Frontiers Research Foundation
CY  - Lausanne, Schweiz
ER  - 
TY  - JOUR
A1  - Mayer, Frank
A1  - Bonaventura, Klaus
A1  - Cassel, Michael
A1  - Müller, Steffen
A1  - Weber, Josefine
A1  - Scharhag-Rosenberger, Friederike
A1  - Carlsohn, Anja
A1  - Baur, Heiner
A1  - Scharhag, Jürgen
T1  - Medical results of preparticipation examination in adolescent athletes
JF  - British journal of sports medicine : the journal of sport and exercise medicine
N2  - Background Preparticipation examinations (PPE) are frequently used to evaluate eligibility for competitive sports in adolescent athletes. Nevertheless, the effectiveness of these examinations is under debate since costs are high and its validity is discussed controversial.
 Purpose To analyse medical findings and consequences in adolescent athletes prior to admission to a sports school.
 Methods In 733 adolescent athletes (318 girls, 415 boys, age 12.3+/-0.4, 16 sports disciplines), history and clinical examination (musculoskeletal, cardiovascular, general medicine) was performed to evaluate eligibility. PPE was completed by determination of blood parameters, ECG at rest and during ergometry, echocardiography and x-rays and ultrasonography if indicated. Eligibility was either approved or rated with restriction. Recommendations for therapy and/or prevention were given to the athletes and their parents.
 Results Historical (h) and clinical (c) findings (eg, pain, verified pathologies) were more frequent regarding the musculoskeletal system (h: 120, 16.4%; c: 247, 33.7%) compared to cardiovascular (h: 9, 1.2%; c: 23, 3.1%) or general medicine findings (h: 116, 15.8%; c: 71, 9.7%). ECG at rest was moderately abnormal in 46 (6.3%) and severely abnormal in 25 athletes (3.4%). Exercise ECG was suspicious in 25 athletes (3.4%). Relevant echocardiographic abnormalities were found in 17 athletes (2.3%). In 52 of 358 cases (14.5%), x-rays led to diagnosis (eg, Spondylolisthesis). Eligibility was temporarily restricted in 41 athletes (5.6%). Three athletes (0.4%) had to be excluded from competitive sports. Therapy (eg, physiotherapy, medication) and/or prevention (sensorimotor training, vaccination) recommendations were deduced due to musculoskeletal (t:n = 76,10.3%; p:n = 71,9.8%) and general medicine findings (t:n = 80, 10.9%; p:n = 104, 14.1%).
 Conclusion Eligibility for competitive sports is restricted in only 5.5% of adolescent athletes at age 12. Eligibility refusals are rare. However, recommendations for therapy and prevention are frequent, mainly regarding the musculoskeletal system. In spite of time and cost consumption, adolescent preparticipation before entering a career in high-performance sports is supported.
Y1  - 2012
U6  - https://doi.org/10.1136/bjsports-2011-090966
SN  - 0306-3674
VL  - 46
IS  - 7
SP  - 524
EP  - 530
PB  - BMJ Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Cassel, Michael
A1  - Müller, Steffen
A1  - Carlsohn, Anja
A1  - Baur, Heiner
A1  - Jerusel, N.
A1  - Mayer, Frank
T1  - Intra- and interrater variability of sonographic investigations of patella and achilles tendons
JF  - Sportverletzung, Sportschaden : Grundlagen, Prävention, Rehabilitation
N2  - Background: Clinical examinations of tendon disorders routinely include ultrasound examinations, despite the fact that availability of data concerning validity criteria of these measurements are limited. The present study therefore aims to evaluate the reliability of measurements of Achilles- and Patella tendon diameter and in the detection of structural adaptations.
 Materials and Methods: In 14 healthy, recreationally active subjects both asymptomatic Achilles (AT) and patella tendons (PT) were measured twice by two examiners in a test-retest design. Besides the detection of anteroposterior (a.p.-) and mediolateral (m.l.-) diameters, areas of hypoechogenicity and neovascularisation were registered. Data were analysed descriptively with calculation of test-retest variability (TRV), intraclass-correlation coefficient (ICC) and Bland and Altman's plots with bias and 95% limits of agreement (LOA).
 Results: Intra- and interrater differences of AT- and PT-a.p.-diameter varied from 0.2 - 1.2 mm, those of AT- and PT-m.l-diameter from 0.7-5.1 mm. Areas of hypoechogenicity were visible in 24% of the tendons, while 15% showed neovascularisations. Intrarater AT-a.p.-diameters showed sparse deviations (TRV 4.5-7.4%; ICC 0.60-0.84; bias -0.05-0.07 mm; LOA-0.6-0.5 to -1.1 - 1.0 mm), while interrater AT- and PT-m.l.-diameters were highly variable (TRV 13.7-19.7%; ICC 0.11-0.20; bias -1.4-4.3 mm; LOA-5.5-2.7 to -10.5 - 1.9 mm).
 Conclusion: Our results suggest that the measurement of AT- and PT-a.p.-diameters is a reliable parameter. In contrast, reproducibility of AT- and PT-m.l.-diameters is questionable. The study corroborates the presence of hypoechogenicity and neovascularisation in asymptomatic tendons.
KW  - ultrasound
KW  - Achilles tendon
KW  - Patella tendon
KW  - intra- and inter-rater variability
KW  - tendon diameter
Y1  - 2012
U6  - https://doi.org/10.1055/s-0031-1281839
SN  - 0932-0555
VL  - 26
IS  - 1
SP  - 21
EP  - 26
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Baur, Heiner
A1  - Hirschmüller, Anja
A1  - Müller, Steffen
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Is EMG of the lower leg dependent on weekly running mileage?
JF  - International journal of sports medicine
N2  - Neuromuscular activity of the lower leg is dependent on the task performed, speed of movement and gender. Whether training volume influences neuromuscular activity is not known. The EMG of physically active persons differing in running mileage was analysed to investigate this. 55 volunteers were allocated to a low (LM: < 30 km), intermediate (IM: > 30 km & < 45 km) or high mileage (HM: > 45 km) group according to their weekly running volume. Neuromuscular activity of the lower leg was measured during running (3.33 m.s(-1)). Mean amplitude values for preactivation, weight acceptance and push-off were calculated and normalised to the mean activity of the entire gait cycle. Higher activity in the gastrocnemius group was observed in weight acceptance in LM compared to IM (+30%) and HM (+25%) but lower activity was present in the push-off for LM compared to IM and HM. For the peroneal muscle, differences were present in the push-off where HM showed increased activity compared to IM (+24%) and LM (+60%). The tibial muscle revealed slightly lower activity during preactivation for the high mileage runners. Neuromuscular activity differs during stance between the high and intermediate group compared to low mileage runners. Slight adaptations in neuromuscular activation indicate a more target-oriented activation strategy possibly due to repetitive training in runners with higher weekly mileage.
KW  - locomotion
KW  - neuromuscular control
KW  - running gait
KW  - training volume
Y1  - 2012
U6  - https://doi.org/10.1055/s-0031-1286250
SN  - 0172-4622
VL  - 33
IS  - 1
SP  - 53
EP  - 57
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - CHAP
A1  - Wochatz, Monique
A1  - Cassel, Michael
A1  - König, Niklas
A1  - Fröhlich, Katja
A1  - Mayer, Frank
T1  - Intra- and inter-observer variability of a retrospective analysis of achilles tendon ultrasound scans
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2013
SN  - 0195-9131
SN  - 1530-0315
VL  - 45
IS  - 5
SP  - 239
EP  - 239
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - CHAP
A1  - Cassel, Michael
A1  - Carlsohn, Anja
A1  - Froehlich, Katja
A1  - Mayer, Frank
T1  - Achilles tendinopathy in adolescent athletes using ultrasound and clinical examination
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2013
SN  - 0195-9131
SN  - 1530-0315
VL  - 45
IS  - 5
SP  - 350
EP  - 350
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - CHAP
A1  - Intziegianni, Konstantina
A1  - Cassel, Michael
A1  - Müller, Steffen
A1  - Mayer, Frank
T1  - Ultrasound evaluation of the patellar tendon cross-sectional area and its relation to maximum force
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2012
SN  - 0195-9131
VL  - 44
SP  - 714
EP  - 714
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - König, Niklas
A1  - Cassel, Michael
A1  - Intziegianni, Konstantina
A1  - Mayer, Frank
T1  - Inter-rater reliability and measurement error of sonographic muscle architecture assessments
JF  - Journal of ultrasound in medicine
N2  - Objectives-Sonography of muscle architecture provides physicians and researchers with information about muscle function and muscle-related disorders. Inter-rater reliability is a crucial parameter in daily clinical routines. The aim of this study was to assess the inter-rater reliability of sonographic muscle architecture assessments and quantification of errors that arise from inconsistent probe positioning and image interpretation.
 Results-Inter-rater reliability was good overall (ICC, 0.77-0.90; IRV, 9.0%-13.4%; bias LoA, 0.2 +/- 0.2-1.7 +/- 3.0). Superior and inferior pennation angles showed high systematic bias and LoA in all setups, ranging from 2.0 degrees +/- 2.2 degrees to 3.4 degrees +/- 4.1 degrees. The highest IRV was found for muscle thickness (13.4%). "When the probe position was standardized, the SEM for muscle thickness decreased from 0.1 to 0.05 cm.
 Conclusions-Sonographic examination of muscle architecture of the medial gastrocnemius has good to high reliability. In contrast to pennation angle measurements, length measurements can be improved by standardization of the probe position.
KW  - gastrocnemius muscle
KW  - inter-rater variability
KW  - muscle architecture
KW  - musculoskeletal ultrasound
KW  - sonography
Y1  - 2014
U6  - https://doi.org/10.7863/ultra.33.5.769
SN  - 0278-4297
SN  - 1550-9613
VL  - 33
IS  - 5
SP  - 769
EP  - 777
PB  - American Institute of Ultrasound in Medicine
CY  - Laurel
ER  - 
TY  - CHAP
A1  - Hain, Gerrit
A1  - Cassel, Michael
A1  - Intziegianni, Konstantina
A1  - Mayer, Frank
T1  - Achilles tendon cross-sectional area changes during maximal voluntary isometric plantar-flexion contraction in healthy individuals.
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2014
SN  - 0195-9131
SN  - 1530-0315
VL  - 46
IS  - 5
SP  - 47
EP  - 47
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - CHAP
A1  - Müller, Steffen
A1  - Cassel, Michael
A1  - Müller, Juliane
A1  - Stoll, Josefine
A1  - Baur, Heiner
A1  - Mayer, Frank
T1  - Trunk strength in adolescent athletes with Spondylolisthesis with/without back pain during training: Pilot study
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2014
SN  - 0195-9131
SN  - 1530-0315
VL  - 46
IS  - 5
SP  - 642
EP  - 642
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - CHAP
A1  - Intziegianni, Konstantina
A1  - Cassel, Michael
A1  - Hain, Gerrit
A1  - Fröhlic, Katja
A1  - Mayer, Frank
T1  - Reliability of sonographic assessment of Achilles tendon cross-sectional area at rest and maximal voluntary contraction
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2014
SN  - 0195-9131
SN  - 1530-0315
VL  - 46
IS  - 5
SP  - 47
EP  - 47
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - CHAP
A1  - Reschke, Antje
A1  - Cassel, Michael
A1  - Intziegianni, Konstantina
A1  - Mayer, Frank
T1  - Intra- and inter-rater reliability of sonographic cross-sectional area measurements in asymptomatic patella tendons
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2014
SN  - 0195-9131
SN  - 1530-0315
VL  - 46
IS  - 5
SP  - 927
EP  - 928
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - CHAP
A1  - Engel, Tilman
A1  - Kopinski, Stephan
A1  - Carlsohn, Anja
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Correlation of sonographic subcutaneous adipose tissue measurements with air displacement plethysmography and calipermetry
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2014
SN  - 0195-9131
SN  - 1530-0315
VL  - 46
IS  - 5
SP  - 539
EP  - 539
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - CHAP
A1  - Kopinski, Stephan
A1  - Engel, Tilman
A1  - Cassel, Michael
A1  - Carlsohn, Anja
A1  - Mayer, Frank
T1  - Reliability of ultrasound measurements for subcutaneous adipose tissue in elite canoe athletes
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2014
SN  - 0195-9131
SN  - 1530-0315
VL  - 46
IS  - 5
SP  - 539
EP  - 539
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - GEN
A1  - Wahmkow, Gunnar
A1  - Cassel, Michael
A1  - Mayer, Frank
A1  - Baur, Heiner
T1  - Effects of different medial arch support heights on rearfoot kinematics
N2  - Background

Foot orthoses are usually assumed to be effective by optimizing mechanically dynamic rearfoot configuration. However, the effect from a foot orthosis on kinematics that has been demonstrated scientifically has only been marginal. The aim of this study was to examine the effect of different heights in medial arch-supported foot orthoses on rear foot motion during gait.

Methods

Nineteen asymptomatic runners (36±11years, 180±5cm, 79±10kg; 41±22km/week) participated in the study. Trials were recorded at 3.1 mph (5 km/h) on a treadmill. Athletes walked barefoot and with 4 different not customized medial arch-supported foot orthoses of various arch heights (N:0 mm, M:30 mm, H:35 mm, E:40mm). Six infrared cameras and the `Oxford Foot Model´ were used to capture motion. The average stride in each condition was calculated from 50 gait cycles per condition. Eversion excursion and internal tibia rotation were analyzed. Descriptive statistics included calculating the mean ± SD and 95% CIs. Group differences by condition were analyzed by one factor (foot orthoses) repeated measures ANOVA (α = 0.05).

Results

Eversion excursion revealed the lowest values for N and highest for H (B:4.6°±2.2°; 95% CI [3.1;6.2]/N:4.0°±1.7°; [2.9;5.2]/M:5.2°±2.6°; [3.6;6.8]/H:6.2°±3.3°; [4.0;8.5]/E:5.1°±3.5°; [2.8;7.5]) (p>0.05). Range of internal tibia rotation was lowest with orthosis H and highest with E (B:13.3°±3.2°; 95% CI [11.0;15.6]/N:14.5°±7.2°; [9.2;19.6]/M:13.8°±5.0°; [10.8;16.8]/H:12.3°±4.3°; [9.0;15.6]/E:14.9°±5.0°; [11.5;18.3]) (p>0.05). Differences between conditions were small and the intrasubject variation high.

Conclusion

Our results indicate that different arch support heights have no systematic effect on eversion excursion or the range of internal tibia rotation and therefore might not exert a crucial influence on rear foot alignment during gait.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 348 
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-402934
ER  - 
TY  - JOUR
A1  - Wahmkow, Gunnar
A1  - Cassel, Michael
A1  - Mayer, Frank
A1  - Baur, Heiner
T1  - Effects of different medial arch support heights on rearfoot kinematics
JF  - PLoS one
N2  - Background

Foot orthoses are usually assumed to be effective by optimizing mechanically dynamic rearfoot configuration. However, the effect from a foot orthosis on kinematics that has been demonstrated scientifically has only been marginal. The aim of this study was to examine the effect of different heights in medial arch-supported foot orthoses on rear foot motion during gait.

Methods

Nineteen asymptomatic runners (36±11years, 180±5cm, 79±10kg; 41±22km/week) participated in the study. Trials were recorded at 3.1 mph (5 km/h) on a treadmill. Athletes walked barefoot and with 4 different not customized medial arch-supported foot orthoses of various arch heights (N:0 mm, M:30 mm, H:35 mm, E:40mm). Six infrared cameras and the `Oxford Foot Model´ were used to capture motion. The average stride in each condition was calculated from 50 gait cycles per condition. Eversion excursion and internal tibia rotation were analyzed. Descriptive statistics included calculating the mean ± SD and 95% CIs. Group differences by condition were analyzed by one factor (foot orthoses) repeated measures ANOVA (α = 0.05).

Results

Eversion excursion revealed the lowest values for N and highest for H (B:4.6°±2.2°; 95% CI [3.1;6.2]/N:4.0°±1.7°; [2.9;5.2]/M:5.2°±2.6°; [3.6;6.8]/H:6.2°±3.3°; [4.0;8.5]/E:5.1°±3.5°; [2.8;7.5]) (p>0.05). Range of internal tibia rotation was lowest with orthosis H and highest with E (B:13.3°±3.2°; 95% CI [11.0;15.6]/N:14.5°±7.2°; [9.2;19.6]/M:13.8°±5.0°; [10.8;16.8]/H:12.3°±4.3°; [9.0;15.6]/E:14.9°±5.0°; [11.5;18.3]) (p>0.05). Differences between conditions were small and the intrasubject variation high.

Conclusion

Our results indicate that different arch support heights have no systematic effect on eversion excursion or the range of internal tibia rotation and therefore might not exert a crucial influence on rear foot alignment during gait.
Y1  - 2017
U6  - https://doi.org/10.1371/journal.pone.0172334
SN  - 1932-6203
VL  - 12
IS  - 3
PB  - PLoS
CY  - Lawrence, Kan.
ER  - 
TY  - GEN
A1  - Cassel, Michael
A1  - Müller, Juliane
A1  - Moser, Othmar
A1  - Strempler, Mares Elaine
A1  - Reso, Judith
A1  - Mayer, Frank
T1  - Orthopedic Injury Profiles in Adolescent Elite Athletes
BT  - A Retrospective Analysis From a Sports Medicine Department
T2  - Postprints der Universität Potsdam Humanwissenschaftliche Reihe
N2  - Aim: The aim of the study was to identify common orthopedic sports injury profiles in adolescent elite athletes with respect to age, sex, and anthropometrics.

Methods: A retrospective data analysis of 718 orthopedic presentations among 381 adolescent elite athletes from 16 different sports to a sports medical department was performed. Recorded data of history and clinical examination included area, cause and structure of acute and overuse injuries. Injury-events were analyzed in the whole cohort and stratified by age (11–14/15–17 years) and sex. Group differences were tested by chi-squared-tests. Logistic regression analysis was applied examining the influence of factors age, sex, and body mass index (BMI) on the outcome variables area and structure (a = 0.05).

Results: Higher proportions of injury-events were reported for females (60%) and athletes of the older age group (66%) than males and younger athletes. The most frequently injured area was the lower extremity (47%) followed by the spine (30.5%) and the upper extremity (12.5%). Acute injuries were mainly located at the lower extremity (74.5%), while overuse injuries were predominantly observed at the lower extremity (41%) as well as the spine (36.5%). Joints (34%), muscles (22%), and tendons (21.5%) were found to be the most often affected structures. The injured structures were different between the age groups (p = 0.022), with the older age group presenting three times more frequent with ligament pathology events (5.5%/2%) and less frequent with bony problems (11%/20.5%) than athletes of the younger age group. The injured area differed between the sexes (p = 0.005), with males having fewer spine injury-events (25.5%/34%) but more upper extremity injuries (18%/9%) than females. Regression analysis showed statistically significant influence for BMI (p = 0.002) and age (p = 0.015) on structure, whereas the area was significantly influenced by sex (p = 0.005).

Conclusion: Events of soft-tissue overuse injuries are the most common reasons resulting in orthopedic presentations of adolescent elite athletes. Mostly, the lower extremity and the spine are affected, while sex and age characteristics on affected area and structure must be considered. Therefore, prevention strategies addressing the injury-event profiles should already be implemented in early adolescence taking age, sex as well as injury entity into account.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 559 
KW  - overuse injuries
KW  - epidemiology
KW  - complaints
KW  - symptoms
KW  - risk factors
KW  - sports
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434953
SN  - 1866-8364
IS  - 559
ER  - 
TY  - JOUR
A1  - Cassel, Michael
A1  - Müller, Juliane
A1  - Moser, Othmar
A1  - Strempler, Mares Elaine
A1  - Reso, Judith
A1  - Mayer, Frank
T1  - Orthopedic Injury Profiles in Adolescent Elite Athletes
BT  - A Retrospective Analysis From a Sports Medicine Department
JF  - Frontiers in Physiology
N2  - Aim: The aim of the study was to identify common orthopedic sports injury profiles in adolescent elite athletes with respect to age, sex, and anthropometrics.

Methods: A retrospective data analysis of 718 orthopedic presentations among 381 adolescent elite athletes from 16 different sports to a sports medical department was performed. Recorded data of history and clinical examination included area, cause and structure of acute and overuse injuries. Injury-events were analyzed in the whole cohort and stratified by age (11–14/15–17 years) and sex. Group differences were tested by chi-squared-tests. Logistic regression analysis was applied examining the influence of factors age, sex, and body mass index (BMI) on the outcome variables area and structure (a = 0.05).

Results: Higher proportions of injury-events were reported for females (60%) and athletes of the older age group (66%) than males and younger athletes. The most frequently injured area was the lower extremity (47%) followed by the spine (30.5%) and the upper extremity (12.5%). Acute injuries were mainly located at the lower extremity (74.5%), while overuse injuries were predominantly observed at the lower extremity (41%) as well as the spine (36.5%). Joints (34%), muscles (22%), and tendons (21.5%) were found to be the most often affected structures. The injured structures were different between the age groups (p = 0.022), with the older age group presenting three times more frequent with ligament pathology events (5.5%/2%) and less frequent with bony problems (11%/20.5%) than athletes of the younger age group. The injured area differed between the sexes (p = 0.005), with males having fewer spine injury-events (25.5%/34%) but more upper extremity injuries (18%/9%) than females. Regression analysis showed statistically significant influence for BMI (p = 0.002) and age (p = 0.015) on structure, whereas the area was significantly influenced by sex (p = 0.005).

Conclusion: Events of soft-tissue overuse injuries are the most common reasons resulting in orthopedic presentations of adolescent elite athletes. Mostly, the lower extremity and the spine are affected, while sex and age characteristics on affected area and structure must be considered. Therefore, prevention strategies addressing the injury-event profiles should already be implemented in early adolescence taking age, sex as well as injury entity into account.
KW  - overuse injuries
KW  - epidemiology
KW  - complaints
KW  - symptoms
KW  - risk factors
KW  - sports
Y1  - 2019
U6  - https://doi.org/10.3389/fphys.2019.00544
SN  - 1664-042X
VL  - 10
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Intziegianni, Konstantina
A1  - Cassel, Michael
A1  - Rauf, S.
A1  - White, S.
A1  - Rector, Michael V.
A1  - Kaplick, Hannes
A1  - Wahmkow, Gunnar
A1  - Kratzenstein, S.
A1  - Mayer, Frank
T1  - Influence of Age and Pathology on Achilles Tendon Properties During a Single-leg Jump
JF  - International journal of sports medicine
N2  - Prevalence of Achilles tendinopathy increases with age leading to a weaker tendon with predisposition to rupture. Conclusive evidence of the influence of age and pathology on Achilles tendon (AT) properties remains limited, as previous studies are based on standardized isometric conditions. The study investigates the influence of age and pathology on AT properties during single-leg vertical jump (SLVJ). 10 children (C), 10 asymptomatic adults (A), and 10 tendinopathic patients (T) were included. AT elongation [mm] from rest to maximal displacement during a SLVJ on a force-plate was sonographically assessed. AT compliance [mm/N]) and strain [%] was calculated by dividing elongation by peak ground reaction force [N] and length, respectively. One-way ANOVA followed by Bonferroni post-hoc correction (=0.05) were used to compare C with A and A with T. AT elongation (p=0.004), compliance (p=0.001), and strain were found to be statistically significant higher in C (27 +/- 3mm, 0.026 +/- 0.006[mm/N], 13 +/- 2%) compared to A (21 +/- 4mm, 0.017 +/- 0.005[mm/N], 10 +/- 2%). No statistically significant differences (p0.05) was found between A and T (25 +/- 5mm, 0.019 +/- 0.004[mm/N], 12 +/- 3%). During SLVJ, tendon responded differently in regards to age and pathology with children having the most compliant AT. Higher compliance found in healthy tendons might be considered as a protective factor against load-related injuries.
KW  - children
KW  - tendinopathy
KW  - compliance
KW  - dynamic
KW  - ultrasonography
Y1  - 2016
U6  - https://doi.org/10.1055/s-0042-108198
SN  - 0172-4622
SN  - 1439-3964
VL  - 37
SP  - 973
EP  - 978
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - GEN
A1  - Müller, Steffen
A1  - Müller, Juliane
A1  - Stoll, Josefine
A1  - Prieske, Olaf
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Incidence of back pain in adolescent athletes
BT  - a prospective study
N2  - Background

Recently, the incidence rate of back pain (BP) in adolescents has been reported at 21%. However, the development of BP in adolescent athletes is unclear. Hence, the purpose of this study was to examine the incidence of BP in young elite athletes in relation to gender and type of sport practiced.

Methods

Subjective BP was assessed in 321 elite adolescent athletes (m/f 57%/43%; 13.2 ± 1.4 years; 163.4 ± 11.4 cm; 52.6 ± 12.6 kg; 5.0 ± 2.6 training yrs; 7.6 ± 5.3 training h/week). Initially, all athletes were free of pain. The main outcome criterion was the incidence of back pain [%] analyzed in terms of pain development from the first measurement day (M1) to the second measurement day (M2) after 2.0 ± 1.0 year. Participants were classified into athletes who developed back pain (BPD) and athletes who did not develop back pain (nBPD). BP (acute or within the last 7 days) was assessed with a 5-step face scale (face 1–2 = no pain; face 3–5 = pain). BPD included all athletes who reported faces 1 and 2 at M1 and faces 3 to 5 at M2. nBPD were all athletes who reported face 1 or 2 at both M1 and M2. Data was analyzed descriptively. Additionally, a Chi2 test was used to analyze gender- and sport-specific differences (p = 0.05).

Results

Thirty-two athletes were categorized as BPD (10%). The gender difference was 5% (m/f: 12%/7%) but did not show statistical significance (p = 0.15). The incidence of BP ranged between 6 and 15% for the different sport categories. Game sports (15%) showed the highest, and explosive strength sports (6%) the lowest incidence. Anthropometrics or training characteristics did not significantly influence BPD (p = 0.14 gender to p = 0.90 sports; r2 = 0.0825).

Conclusions

BP incidence was lower in adolescent athletes compared to young non-athletes and even to the general adult population. Consequently, it can be concluded that high-performance sports do not lead to an additional increase in back pain incidence during early adolescence. Nevertheless, back pain prevention programs should be implemented into daily training routines for sport categories identified as showing high incidence rates.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 310 
KW  - Injury
KW  - Pain occurrence
KW  - Training volume
KW  - Young athletes
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-101874
ER  - 
TY  - JOUR
A1  - Müller, Steffen
A1  - Müller, Juliane
A1  - Stoll, Josefine
A1  - Prieske, Olaf
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Incidence of back pain in adolescent athletes
BT  - a prospective study
JF  - BMC sports science, medicine & rehabilitation
N2  - Background

Recently, the incidence rate of back pain (BP) in adolescents has been reported at 21%. However, the development of BP in adolescent athletes is unclear. Hence, the purpose of this study was to examine the incidence of BP in young elite athletes in relation to gender and type of sport practiced.

Methods

Subjective BP was assessed in 321 elite adolescent athletes (m/f 57%/43%; 13.2 ± 1.4 years; 163.4 ± 11.4 cm; 52.6 ± 12.6 kg; 5.0 ± 2.6 training yrs; 7.6 ± 5.3 training h/week). Initially, all athletes were free of pain. The main outcome criterion was the incidence of back pain [%] analyzed in terms of pain development from the first measurement day (M1) to the second measurement day (M2) after 2.0 ± 1.0 year. Participants were classified into athletes who developed back pain (BPD) and athletes who did not develop back pain (nBPD). BP (acute or within the last 7 days) was assessed with a 5-step face scale (face 1–2 = no pain; face 3–5 = pain). BPD included all athletes who reported faces 1 and 2 at M1 and faces 3 to 5 at M2. nBPD were all athletes who reported face 1 or 2 at both M1 and M2. Data was analyzed descriptively. Additionally, a Chi2 test was used to analyze gender- and sport-specific differences (p = 0.05).

Results

Thirty-two athletes were categorized as BPD (10%). The gender difference was 5% (m/f: 12%/7%) but did not show statistical significance (p = 0.15). The incidence of BP ranged between 6 and 15% for the different sport categories. Game sports (15%) showed the highest, and explosive strength sports (6%) the lowest incidence. Anthropometrics or training characteristics did not significantly influence BPD (p = 0.14 gender to p = 0.90 sports; r2 = 0.0825).

Conclusions

BP incidence was lower in adolescent athletes compared to young non-athletes and even to the general adult population. Consequently, it can be concluded that high-performance sports do not lead to an additional increase in back pain incidence during early adolescence. Nevertheless, back pain prevention programs should be implemented into daily training routines for sport categories identified as showing high incidence rates.
KW  - Pain occurrence
KW  - Young athletes
KW  - Injury
KW  - Training volume
Y1  - 2016
U6  - https://doi.org/10.1186/s13102-016-0064-7
SN  - 2052-1847
VL  - 8
PB  - BioMed Central
CY  - London
ER  - 
TY  - JOUR
A1  - Baur, Heiner
A1  - Hirschmüller, Anja
A1  - Cassel, Michael
A1  - Müller, Steffen
A1  - Mayer, Frank
T1  - Gender-specific neuromuscular activity of the M. peroneus longus in healthy runners : a descriptive laboratory study
N2  - Background: Gender-specific neuromuscular activity for the ankle (e.g., peroneal muscle) is currently not known. This knowledge may contribute to the understanding of overuse injury mechanisms. The purpose was therefore to analyse the neuromuscular activity of the peroneal muscle in healthy runners. Methods: Fifty-three male and 54 female competitive runners were tested on a treadmill at 3.33 m s(-1). Neuromuscular activity of the M. peroneus longus was measured by electromyography and analysed in the time domain (onset of activation, time of maximum of activation, total time of activation) in % of stride time in relation to touchdown (= 1.0). Additionally, mean amplitudes for the gait cycle phases preactivation, weight acceptance and push-off were calculated and normalised to the mean activity of the entire gait cycle. Findings: Onset of activation (mean; female: 0.86/male: 0.90, p<0.0001) and time of maximum of activation (female: 1.13/male: 1.16, p<0.0001) occurred earlier in female compared to male and the total time of activation was longer in women (female: 0.42/male: 0.39, p=0.0036). In preactivation, women showed higher amplitudes (+ 21%) compared to men (female: 1.16/male: 0.92, p<0.0001). Activity during weight acceptance (female: 2.26/male: 2.41, p = 0.0039) and push-off (female: 0.93/male: 1.07, p = 0.0027) were higher in men. Interpretation: Activation strategies of the peroneal muscle appear to be gender-specific. Higher preactivation amplitudes in females indicate a different neuromuscular control in anticipation of touchdown ("pre-programmed activity"). These data may help interpret epidemiologically reported differences between genders in overuse injury frequency and localisation.
Y1  - 2010
UR  - http://www.sciencedirect.com/science/journal/02680033
U6  - https://doi.org/10.1016/j.clinbiomech.2010.06.009
SN  - 0268-0033
ER  - 
TY  - CHAP
A1  - Intziegianni, Konstantina
A1  - Cassel, Michael
A1  - König, Niklas
A1  - Mayer, Frank
T1  - Reliability of variables defining mechanical and material properties of the achilles tendon
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2013
SN  - 0195-9131
SN  - 1530-0315
VL  - 45
IS  - 5
SP  - 238
EP  - 239
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Scharhag-Rosenberger, Friederike
A1  - Carlsohn, Anja
A1  - Cassel, Michael
A1  - Mayer, Frank
A1  - Scharhag, Jürgen
T1  - How to test maximal oxygen uptake a study on timing and testing procedure of a supramaximal verification test
JF  - Applied physiology, nutrition, and metabolism = Physiologie appliquée, nutrition et métabolisme
N2  - On utilise de plus en plus les tests de verification pour confirmer l'atteinte du consommation d'oxygene maximale (VO(2 max)). Toutefois, le moment et les methodes d'evaluation varient d'un groupe de travail a l'autre. Les objectifs de cette etude sont de constater si on peut administrer un test de verification apres un test d'effort progressif ou s'il est preferable de le faire une autre journee et si on peut determiner le VO(2 max) tout de meme lors de la premiere seance chez des sujets ne repondant pas au critere de verification. Quarante sujets (age, 24 +/- 4 ans; VO(2 max), 50 +/- 7 mL center dot min(-1)center dot kg(-1)) participent a un test d'effort progressif sur tapis roulant et, 10 min plus tard, a un test de verification (VerifDay1) a 110 % de la velocite maximale (v(max)). Le critere de verification est un VO(2) de pointe au VerifDay1 < 5,5 % a la valeur retenue au test d'effort progressif. Les sujets ne repondant pas au critere de verification passent un autre test de verification, mais a 115 % du VerifDay1', et ce, 10 min plus tard pour confirmer le VO(2) de pointe du VerifDay1 en tant que VO(2 max). Tous les autres sujets repassent le VerifDay1 a un jour different (VerifDay2). Six sujets sur quarante ne repondent pas au critere de verification. Chez quatre d'entre eux, on confirme l'atteinte du VO(2 max) au VerifDay1'. Le VO(2) de pointe au VerifDay1 est equivalent a celui du VerifDay2 (3722 +/- 991 mL center dot min(-1) comparativement a 3752 +/- 995 mL center dot min(-1), p = 0,56), mais le temps jusqu'a l'epuisement est significativement plus long au VerifDay2 (2:06 +/- 0:22 min:s comparativement a 2:42 +/- 0:38 min:s, p < 0,001, n = 34). Le VO(2) de pointe obtenu au test de verification ne semble pas conditionne par un test d'effort progressif maximal prealable. On peut donc realiser le test d'effort progressif et le test de verification lors de la meme seance d'evaluation. Chez presque tous les individus ne repondant pas au critere de verification, on peut determiner le VO(2 max) au moyen d'un autre test de verification plus intense.
Y1  - 2011
U6  - https://doi.org/10.1139/H10-099
SN  - 1715-5312
VL  - 36
IS  - 1
SP  - 153
EP  - 160
PB  - NRC Research Press
CY  - Ottawa
ER  - 
TY  - JOUR
A1  - Scharhag-Rosenberger, Friederike
A1  - Wochatz, Monique
A1  - Otto, Christoph
A1  - Cassel, Michael
A1  - Mayer, Frank
A1  - Scharhag, Jürgen
T1  - Blood lactate concentrations are mildly affected by mobile gas exchange measurements
JF  - International journal of sports medicine
N2  - We sought to investigate the effects of wearing a mobile respiratory gas analysis system during a treadmill test on blood lactate (bLa) concentrations and commonly applied bLa thresholds. A total of 16 recreational athletes (31 +/- 3 years, V0205: 58 6 ml min(-1)-kg(-1)) performed one multistage treadmill test with and one without gas exchange measurements (GEM and noGEM). The whole bLa curve, the lactate threshold (LT), the individual anaerobic thresholds according to Stegmann(IAT(sr)) and Dickhuth (IAT(Di)), and a fixed bLa concentration of 4 mmob.l(-1) (OBLA) were evaluated. The bLa curve was shifted slightly leftward in GEM compared to noGEM (P<0.05), whereas the heart rate response was not different between conditions (P= 0.89). There was no difference between GEM and noGEM for LT (2.61 +/- 0.34 vs. 2.64 +/- 0.39 m(-1) s(-1) P=0.49) and IAT(st) (3.47 +/- 0.42 vs. 3.55 +/- 0.47m-s(-1), P=0.12). However, IATD(Di) (3.57 +/- 0.39 vs. 3.66 +/- 0.44m-s(-1), P<0.01) and OBLA (3.85 +/- 0.46 vs. 3.96 +/- 0.47m-s-1, P<0.01) occurred at slower running velocities in GEM. The bLa response to treadmill tests is mildly affected by wearing a mobile gas analysis system. This also applies to bLa thresholds located at higher exercise intensities. While the magnitude of the effects is of little importance for recreational athletes, it might be relevant for elite athletes and scientific studies.
KW  - cardiopulmonary exercise testing
KW  - performance diagnostics
KW  - lactate threshold
KW  - VO2mdx
KW  - metabolic device
Y1  - 2014
U6  - https://doi.org/10.1055/s-0033-1354386
SN  - 0172-4622
SN  - 1439-3964
VL  - 35
IS  - 7
SP  - 590
EP  - 594
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Carlsohn, Anja
A1  - Scharhag-Rosenberger, Friederike
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Resting metabolic rate in elite rowers and canoeists difference between indirect calorimetry and prediction
JF  - Annals of nutrition & metabolism : journal of nutrition, metabolic diseases and dietetics ; an official journal of International Union of Nutritional Sciences (IUNS)
N2  - Background: Athletes may differ in their resting metabolic rate (RMR) from the general population. However, to estimate the RMR in athletes, prediction equations that have not been validated in athletes are often used. The purpose of this study was therefore to verify the applicability of commonly used RMR predictions for use in athletes. Methods: The RMR was measured by indirect calorimetry in 17 highly trained rowers and canoeists of the German national teams (BMI 24 +/- 2 kg/m(2), fat-free mass 69 +/- 15 kg). In addition, the RMR was predicted using Cunningham (CUN) and Harris-Benedict (HB) equations. A two-way repeated measures ANOVA was calculated to test for differences between predicted and measured RMR (alpha = 0.05). The root mean square percentage error (RMSPE) was calculated and the Bland-Altman procedure was used to quantify the bias for each prediction. Results: Prediction equations significantly underestimated the RMR in males (p < 0.001). The RMSPE was calculated to be 18.4% (CUN) and 20.9% (HB) in the entire group. The bias was 133 kcal/24 h for CUN and 202 kcal/24 h for HB. Conclusions: Predictions significantly underestimate the RMR in male heavyweight endurance athletes but not in females. In athletes with a high fat-free mass, prediction equations might therefore not be applicable to estimate energy requirements. Instead, measurement of the resting energy expenditure or specific prediction equations might be needed for the individual heavyweight athlete.
KW  - Energy requirement
KW  - Calorimetry
KW  - Fat-free mass
KW  - Nutritional counseling
KW  - Athletes
Y1  - 2011
U6  - https://doi.org/10.1159/000330119
SN  - 0250-6807
VL  - 58
IS  - 3
SP  - 239
EP  - 244
PB  - Karger
CY  - Basel
ER  - 
TY  - JOUR
A1  - Baur, Heiner
A1  - Müller, Steffen
A1  - Hirschmüller, Anja
A1  - Cassel, Michael
A1  - Weber, Josefine
A1  - Mayer, Frank
T1  - Comparison in lower leg neuromuscular activity between runners with unilateral mid-portion Achilles tendinopathy and healthy individuals
JF  - Journal of electromyography and kinesiology
N2  - Neuromuscular control in functional situations and possible impairments due to Achilles tendinopathy are not well understood.
 Thirty controls (CO) and 30 runners with Achilles tendinopathy (AT) were tested on a treadmill at 3.33 m s(-1) (12 km h(-1)). Neuromuscular activity of the lower leg (tibialis anterior, peroneal, and gastrocnemius muscle) was measured by surface electromyography. Mean amplitude values (MAV) for the gait cycle phases preactivation, weight acceptance and push-off were calculated and normalised to the mean activity of the entire gait cycle.
 MAVs of the tibialis anterior did not differ between CO and AT in any gait cycle phase. The activation of the peroneal muscle was lower in AT in weight acceptance (p = 0.006), whereas no difference between CO and AT was found in preactivation (p = 0.71) and push-off (p = 0.83). Also, MAVs of the gastrocnemius muscle did not differ between AT and CO in preactivity (p = 0.71) but were reduced in AT during weight acceptance (p = 0.001) and push-off (p = 0.04).
 Achilles tendinopathy does not seem to alter pre-programmed neural control but might induce mechanical deficits of the lower extremity during weight bearing (joint stability). This should be addressed in the therapy process of AT.
KW  - Ankle joint
KW  - Electromyography
KW  - Overuse injury
KW  - Running gait
Y1  - 2011
U6  - https://doi.org/10.1016/j.jelekin.2010.11.010
SN  - 1050-6411
VL  - 21
IS  - 3
SP  - 499
EP  - 505
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Carlsohn, Anja
A1  - Cassel, Michael
A1  - Linne, Karsten
A1  - Mayer, Frank
T1  - How much is too much? - a case report of nutritional supplement use of a high-performance athlete
JF  - The British journal of nutrition : an international journal devoted to the science of human and animal nutrition
N2  - Although dietary nutrient intake is often adequate, nutritional supplement use is common among elite athletes. However, high-dose supplements or the use of multiple supplements may exceed the recommended daily allowance (RDA) of particular nutrients or even result in a daily intake above tolerable upper limits (UL). The present case report presents nutritional intake data and supplement use of a highly trained male swimmer competing at international level. Habitual energy and micronutrient intake were analysed by 3 d dietary reports. Supplement use and dosage were assessed, and total amount of nutrient supply was calculated. Micronutrient intake was evaluated based on RDA and UL as presented by the European Scientific Committee on Food, and maximum permitted levels in supplements (MPL) are given. The athlete's diet provided adequate micronutrient content well above RDA except for vitamin D. Simultaneous use of ten different supplements was reported, resulting in excess intake above tolerable UL for folate, vitamin E and Zn. Additionally, daily supplement dosage was considerably above MPL for nine micronutrients consumed as artificial products. Risks and possible side effects of exceeding UL by the athlete are discussed. Athletes with high energy intake may be at risk of exceeding UL of particular nutrients if multiple supplements are added. Therefore, dietary counselling of athletes should include assessment of habitual diet and nutritional supplement intake. Educating athletes to balance their diets instead of taking supplements might be prudent to prevent health risks that may occur with long-term excess nutrient intake.
KW  - Dietary supplements
KW  - Tolerable upper limits
KW  - Elite athletes
KW  - Vitamins
KW  - Minerals
Y1  - 2011
U6  - https://doi.org/10.1017/S0007114510005556
SN  - 0007-1145
VL  - 105
IS  - 12
SP  - 1724
EP  - 1728
PB  - Cambridge Univ. Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Mayer, Frank
A1  - Scharhag-Rosenberger, Friederike
A1  - Carlsohn, Anja
A1  - Cassel, Michael
A1  - Müller, Steffen
A1  - Scharhag, Jürgen
T1  - The intensity and effects of strength training in the elderly
JF  - Deutsches Ärzteblatt international : a weekly online journal of clinical medicine and public health
N2  - Background: The elderly need strength training more and more as they grow older to stay mobile for their everyday activities. The goal of training is to reduce the loss of muscle mass and the resulting loss of motor function. The dose-response relationship of training intensity to training effect has not yet been fully elucidated.
 Methods: PubMed was selectively searched for articles that appeared in the past 5 years about the effects and dose-response relationship of strength training in the elderly.
 Results: Strength training in the elderly (> 60 years) increases muscle strength by increasing muscle mass, and by improving the recruitment of motor units, and increasing their firing rate. Muscle mass can be increased through training at an intensity corresponding to 60% to 85% of the individual maximum voluntary strength. Improving the rate of force development requires training at a higher intensity (above 85%), in the elderly just as in younger persons. It is now recommended that healthy old people should train 3 or 4 times weekly for the best results; persons with poor performance at the outset can achieve improvement even with less frequent training. Side effects are rare.
 Conclusion: Progressive strength training in the elderly is efficient, even with higher intensities, to reduce sarcopenia, and to retain motor function.
Y1  - 2011
U6  - https://doi.org/10.3238/arztebl.2011.0359
SN  - 1866-0452
VL  - 108
IS  - 21
SP  - 359
EP  - U30
PB  - Dt. Ärzte-Verl.
CY  - Cologne
ER  - 
TY  - JOUR
A1  - Carlsohn, Anja
A1  - Scharhag-Rosenberger, Friederike
A1  - Cassel, Michael
A1  - Weber, Josefine
A1  - Guzman, Annette de Guzman
A1  - Mayer, Frank
T1  - Physical activity levels to estimate the energy requirement of adolescent athletes
JF  - Pediatric exercise science
N2  - Adequate energy intake in adolescent athletes is considered important. Total energy expenditure (TEE) can be calculated from resting energy expenditure (REE) and physical activity level (PAL). However, validated PAL recommendations are available for adult athletes only. Purpose was to comprise physical activity data in adolescent athletes and to establish PAL recommendations for this population. In 64 competitive athletes (15.3 +/- 1.5yr, 20.5 +/- 2.0kg/m(2)) and 14 controls (15.1 +/- 1.1yr, 21 +/- 2.1kg/m(2)) TEE was calculated using 7-day activity protocols validated against doubly-labeled water. REE was estimated by Schofield-HW equation, and PAL was calculated as TEE:REE. Observed PAL in adolescent athletes (1.90 +/- 0.35) did not differ compared with controls (1.84 +/- 0.32, p = .582) and was lower than recommended for adult athletes by the WHO. In conclusion, applicability of PAL values recommended for adult athletes to estimate energy requirements in adolescent athletes must be questioned. Instead, a PAL range of 1.75-2.05 is suggested.
Y1  - 2011
SN  - 0899-8493
VL  - 23
IS  - 2
SP  - 261
EP  - 269
PB  - Human Kinetics Publ.
CY  - Champaign
ER  - 
TY  - JOUR
A1  - Koch, Sarah
A1  - Cassel, Michael
A1  - Linne, Karsten
A1  - Mayer, Frank
A1  - Scharhag, Jürgen
T1  - ECG and echocardiographic findings in 10-15-year-old elite athletes
JF  - European journal of preventive cardiology : the official ESC journal for primary & secondary cardiovascular prevention, rehabilitation and sports cardiology
N2  - Background: Data on electrocardiographic and echocardiographic pre-participation screening findings in paediatric athletes are limited.
KW  - ECG
KW  - echocardiography
KW  - paediatric athlete
KW  - pre-participation screening
KW  - sudden cardiac death
Y1  - 2014
U6  - https://doi.org/10.1177/2047487312462147
SN  - 2047-4873
SN  - 2047-4881
VL  - 21
IS  - 6
SP  - 774
EP  - 781
PB  - Sage Publ.
CY  - London
ER  - 
TY  - GEN
A1  - Müller, Steffen
A1  - Stoll, Josefine
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Trunk Muscle Activity during Drop Jump Performance in Adolescent Athletes with Back Pain
N2  - In the context of back pain, great emphasis has been placed on the importance of trunk stability, especially in situations requiring compensation of repetitive, intense loading induced during high-performance activities, e.g., jumping or landing. This study aims to evaluate trunk muscle activity during drop jump in adolescent athletes with back pain (BP) compared to athletes without back pain (NBP). Eleven adolescent athletes suffering back pain (BP: m/f: n = 4/7; 15.9 ± 1.3 y; 176 ± 11 cm; 68 ± 11 kg; 12.4 ± 10.5 h/we training) and 11 matched athletes without back pain (NBP: m/f: n = 4/7; 15.5 ± 1.3 y; 174 ± 7 cm; 67 ± 8 kg; 14.9 ± 9.5 h/we training) were evaluated. Subjects conducted 3 drop jumps onto a force plate (ground reaction force). Bilateral 12-lead SEMG (surface Electromyography) was applied to assess trunk muscle activity. Ground contact time [ms], maximum vertical jump force [N], jump time [ms] and the jump performance index [m/s] were calculated for drop jumps. SEMG amplitudes (RMS: root mean square [%]) for all 12 single muscles were normalized to MIVC (maximum isometric voluntary contraction) and analyzed in 4 time windows (100 ms pre- and 200 ms post-initial ground contact, 100 ms pre- and 200 ms post-landing) as outcome variables. In addition, muscles were grouped and analyzed in ventral and dorsal muscles, as well as straight and transverse trunk muscles. Drop jump ground reaction force variables did not differ between NBP and BP (p > 0.05). Mm obliquus externus and internus abdominis presented higher SEMG amplitudes (1.3–1.9-fold) for BP (p < 0.05). Mm rectus abdominis, erector spinae thoracic/lumbar and latissimus dorsi did not differ (p > 0.05). The muscle group analysis over the whole jumping cycle showed statistically significantly higher SEMG amplitudes for BP in the ventral (p = 0.031) and transverse muscles (p = 0.020) compared to NBP. Higher activity of transverse, but not straight, trunk muscles might indicate a specific compensation strategy to support trunk stability in athletes with back pain during drop jumps. Therefore, exercises favoring the transverse trunk muscles could be recommended for back pain treatment.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 319 
KW  - SEMG-pattern
KW  - back pain
KW  - drop jump
KW  - neuromuscular
KW  - performance
KW  - pre-activity
KW  - trunk
KW  - young athletes
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-395261
ER  - 
TY  - GEN
A1  - Bisi-Balogun, Adebisi
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Reliability of various measurement stations for determining plantar fascia thickness and echogenicity
N2  - This study aimed to determine the relative and absolute reliability of ultrasound (US) measurements of the thickness and echogenicity of the plantar fascia (PF) at different measurement stations along its length using a standardized protocol. Twelve healthy subjects (24 feet) were enrolled. The PF was imaged in the longitudinal plane. Subjects were assessed twice to evaluate the intra-rater reliability. A quantitative evaluation of the thickness and echogenicity of the plantar fascia was performed using Image J, a digital image analysis and viewer software. A sonography evaluation of the thickness and echogenicity of the PF showed a high relative reliability with an Intra class correlation coefficient of 0.88 at all measurement stations. However, the measurement stations for both the PF thickness and echogenicity which showed the highest intraclass correlation coefficient (ICCs) did not have the highest absolute reliability. Compared to other measurement stations, measuring the PF thickness at 3 cm distal and the echogenicity at a region of interest 1 cm to 2 cm distal from its insertion at the medial calcaneal tubercle showed the highest absolute reliability with the least systematic bias and random error. Also, the reliability was higher using a mean of three measurements compared to one measurement. To reduce discrepancies in the interpretation of the thickness and echogenicity measurements of the PF, the absolute reliability of the different measurement stations should be considered in clinical practice and research rather than the relative reliability with the ICC.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 339 
KW  - plantar fascia
KW  - reliability
KW  - sonography
KW  - musculoskeletal
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400615
ER  - 
TY  - JOUR
A1  - Müller, Steffen
A1  - Stoll, Josefine
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Trunk Muscle Activity during Drop Jump Performance in Adolescent Athletes with Back Pain
JF  - Frontiers in physiology
N2  - In the context of back pain, great emphasis has been placed on the importance of trunk stability, especially in situations requiring compensation of repetitive, intense loading induced during high-performance activities, e.g., jumping or landing. This study aims to evaluate trunk muscle activity during drop jump in adolescent athletes with back pain (BP) compared to athletes without back pain (NBP). Eleven adolescent athletes suffering back pain (BP: m/f: n = 4/7; 15.9 ± 1.3 y; 176 ± 11 cm; 68 ± 11 kg; 12.4 ± 10.5 h/we training) and 11 matched athletes without back pain (NBP: m/f: n = 4/7; 15.5 ± 1.3 y; 174 ± 7 cm; 67 ± 8 kg; 14.9 ± 9.5 h/we training) were evaluated. Subjects conducted 3 drop jumps onto a force plate (ground reaction force). Bilateral 12-lead SEMG (surface Electromyography) was applied to assess trunk muscle activity. Ground contact time [ms], maximum vertical jump force [N], jump time [ms] and the jump performance index [m/s] were calculated for drop jumps. SEMG amplitudes (RMS: root mean square [%]) for all 12 single muscles were normalized to MIVC (maximum isometric voluntary contraction) and analyzed in 4 time windows (100 ms pre- and 200 ms post-initial ground contact, 100 ms pre- and 200 ms post-landing) as outcome variables. In addition, muscles were grouped and analyzed in ventral and dorsal muscles, as well as straight and transverse trunk muscles. Drop jump ground reaction force variables did not differ between NBP and BP (p > 0.05). Mm obliquus externus and internus abdominis presented higher SEMG amplitudes (1.3–1.9-fold) for BP (p < 0.05). Mm rectus abdominis, erector spinae thoracic/lumbar and latissimus dorsi did not differ (p > 0.05). The muscle group analysis over the whole jumping cycle showed statistically significantly higher SEMG amplitudes for BP in the ventral (p = 0.031) and transverse muscles (p = 0.020) compared to NBP. Higher activity of transverse, but not straight, trunk muscles might indicate a specific compensation strategy to support trunk stability in athletes with back pain during drop jumps. Therefore, exercises favoring the transverse trunk muscles could be recommended for back pain treatment.
KW  - SEMG-pattern
KW  - back pain
KW  - pre-activity
KW  - drop jump
KW  - neuromuscular
KW  - trunk
KW  - performance
KW  - young athletes
Y1  - 2017
U6  - https://doi.org/10.3389/fphys.2017.00274
SN  - 1664-042X
VL  - 8
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Intziegianni, Konstantina
A1  - Cassel, Michael
A1  - König, Niklas
A1  - Müller, Steffen
A1  - Fröhlich, Katja
A1  - Mayer, Frank
T1  - Ultrasonography for the assessment of the structural properties of the Achilles tendon in asymptomatic individuals: An intra-rater reproducibility study
JF  - Isokinetics and exercise science : official journal of the European Isokinetic Society
N2  - BACKGROUND: Reproducible measurements of tendon structural properties are a prerequisite for accurate diagnosis of tendon disorders and for determination of their mechanical properties. Despite the widely used application of Ultrasonography (US) in musculoskeletal assessment, its operator dependency and lack of standardization influences the consistency of the measurement.
 OBJECTIVE: To evaluate the intra-rater reproducibility of a standardized US method assessing the structural properties of the Achilles tendon (AT).
 METHODS: Sixteen asymptomatic participants were positioned prone on an isokinetic dynamometer with the knee extended and ankle at 90. flexion. US was used to assess AT-length, cross-sectional area (CSA), and AT-elongation during isometric plantarflexion contraction. The intra-rater reproducibility was assessed by ICC (2.1), Test-Retest Variability (TRV, %), Bland-Altman analyses (Bias +/- LoA [1.96*SD]), and Standard-Error of Measurement (SEM).
 RESULTS: Measurements of AT-length demonstrated an ICC of 0.93, TRV of 4.5 +/- 3.9%, Bias +/- LoA of -2.8 +/- 25.0 mm and SEM of 6.6 mm. AT-CSA showed an ICC of 0.79, TRV of 8.7 +/- 9.6%, Bias +/- LoA of 1.7 +/- 19.4 mm(2) and SEM of 5.3 mm(2). AT-elongation revealed an ICC of 0.92, TRV of 12.9 +/- 8.9%, Bias +/- LoA of 0.3 +/- 5.7 mm and SEM of 1.5 mm.
 CONCLUSIONS: The presented methodology allows a reproducible assessment of Achilles tendon structural properties when performed by a single rater.
KW  - Ultrasonography
KW  - Achilles tendon
KW  - reproducibility
KW  - isokinetic
Y1  - 2015
U6  - https://doi.org/10.3233/IES-150586
SN  - 0959-3020
SN  - 1878-5913
VL  - 23
IS  - 4
SP  - 263
EP  - 270
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kopinski, Stephan
A1  - Engel, Tilman
A1  - Cassel, Michael
A1  - Fröhlich, Katja
A1  - Mayer, Frank
A1  - Carlsohn, Anja
T1  - Ultrasound Applied to Subcutaneous Fat Tissue Measurements in International Elite Canoeists
JF  - International journal of sports medicine
N2  - Subcutaneous adipose tissue (SAT) measurements with ultrasound have recently been introduced to assess body fat in elite athletes. However, appropriate protocols and data on various groups of athletes are missing. We investigated intra-rater reliability of SAT measurements using ultrasound in elite canoe athletes. 25 international level canoeists (18 male, 7 female; 23 +/- 4 years; 81 +/- 11 kg; 1.83 +/- 0.09 m; 20 +/- 3 training h/wk) were measured on 2 consecutive days. SAT was assessed with B-mode ultrasound at 8 sites (ISAK): triceps, subscapular, biceps, iliac crest, supraspinal, abdominal, front thigh, medial calf, and quantified using image analysis software. Data was analyzed descriptively (mean +/- SD, [range]). Coefficient of variation (CV %), intraclass correlation coefficient (ICC, 2.1) and absolute (LoA) and ratio limits of agreement (RLoA) were calculated for day-to-day reliability. Mean sum of SAT thickness was 30.0 +/- 19.4 mm [8.0, 80.1 mm], with 3.9 +/- 1.8 mm [1.2 mm subscapular, 8.0 mm abdominal] for individual sites. CV for the sum of sites was 4.7 %, ICC 0.99, LoA 1.7 +/- 3.6 mm, RLoA 0.940 (*/divided by 1.155). Measuring SAT with ultrasound has proved to have excellent day-to-day reliability in elite canoe athletes. Recommendations for standardization of the method will further increase accuracy and reproducibility.
KW  - subcutaneous adipose tissue
KW  - skinfold thickness
KW  - elite athletes
KW  - body composition
KW  - ultrasonography
Y1  - 2015
U6  - https://doi.org/10.1055/s-0035-1555857
SN  - 0172-4622
SN  - 1439-3964
VL  - 36
IS  - 14
SP  - 1134
EP  - 1141
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Cassel, Michael
A1  - Baur, Heiner
A1  - Hirschmueller, Anja
A1  - Carlsohn, Anja
A1  - Fröhlich, Katja
A1  - Mayer, Frank
T1  - Prevalence of Achilles and patellar tendinopathy and their association to intratendinous changes in adolescent athletes
JF  - Scandinavian journal of medicine & science in sports
N2  - Achilles (AT) and patellar tendons (PT) are commonly affected by tendinopathy in adult athletes but prevalence of symptoms and morphological changes in adolescents is unclear. The study aimed to determine prevalence of tendinopathy and intratendinous changes in ATs and PTs of adolescent athletes. A total of 760 adolescent athletes (13.0 +/- 1.9 years; 160 +/- 13cm; 50 +/- 14kg) were examined. History, local clinical examination, and longitudinal Doppler ultrasound analysis for both ATs and PTs were performed including identification of intratendinous echoic changes and vascularization. Diagnosis of tendinopathy was complied clinically in case of positive history of tendon pain and tendon pain on palpation. Achilles tendinopathy was diagnosed in 1.8% and patellar tendinopathy in 5.8%. Vascularizations were visible in 3.0% of ATs and 11.4% of PTs, hypoechogenicities in 0.7% and 3.2% as well as hyperechogenicities in 0% and 0.3%, respectively. Vascularizations and hypoechogenicities were statistically significantly more often in males than in females (P0.02). Subjects with patellar tendinopathy had higher prevalence of structural intratendinous changes than those without PT symptoms (P0.001). In adolescent athletes, patellar tendinopathy is three times more frequent compared with Achilles tendinopathy. Longitudinal studies are necessary to investigate physiological or pathological origin of vascularizations and its predictive value in development of tendinopathy.
KW  - Prevalence
KW  - tendinopathy
KW  - sonography
KW  - Doppler ultrasound
KW  - vascularization
KW  - hypoechogenicities
KW  - hyperechogenicities
KW  - adolescent athletes
Y1  - 2015
U6  - https://doi.org/10.1111/sms.12318
SN  - 0905-7188
SN  - 1600-0838
VL  - 25
IS  - 3
SP  - e310
EP  - e318
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Cassel, Michael
A1  - Stoll, Josefine
A1  - Mayer, Frank
T1  - Tendinopathies of the Lower Extremities in Sport - Diagnostics and Therapy
JF  - Sportverletzung, Sportschaden : Grundlagen, Prävention, Rehabilitation
N2  - Tendinopathies are frequently the cause of chronic, load-dependent complaints of the lower extremity. Commonly, the large tendons of the ankle and knee joints are affected, especially the Achilles and patellar tendons. Repeated overuse in sports and/or daily activities is assumed as the aetiology. Besides the clinical examination including a comprehensive anamnesis of pain and training/loading, sonographic imaging has a high training/loading relevance for the diagnosis of tendon pathologies of the lower extremity. Training concepts are considered in first line as the treatment of choice. A combination with physical therapy interventions can be useful. In cases of a more severe pathology and long-standing complaints multimodal therapeutic options should be employed. The use of surgical treatment procedures should only be taken into account in case of failed response to conservative treatment.
KW  - Tendinopathy
KW  - sonography
KW  - principles of therapy
Y1  - 2015
U6  - https://doi.org/10.1055/s-0034-1399668
SN  - 0932-0555
SN  - 1439-1236
VL  - 29
IS  - 2
SP  - 87
EP  - 98
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - CHAP
A1  - Wang, Victor C.
A1  - Mayer, Frank
A1  - Dorenkamp, Marc
A1  - Bonaventura, Klaus
T1  - Three-dimensional global area tracking is a valuable quantitative parameter for left ventricular function in athletes
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
Y1  - 2012
SN  - 0195-9131
VL  - 44
SP  - 850
EP  - 850
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Wippert, Pia-Maria
A1  - De Witt Huberts, Jessie
A1  - Klipker, Kathrin
A1  - Gantz, Simone
A1  - Schiltenwolf, Marcus
A1  - Mayer, Frank
T1  - Development and content of the behavioral therapy module of the MiSpEx intervention. Randomized, controlled trial on chronic nonspecific low back pain
JF  - Der Schmerz : Organ der Deutschen Gesellschaft zum Studium des Schmerzes, der Österreichischen Schmerzgesellschaft und der Deutschen Interdisziplinären Vereinigung für Schmerztherapie
N2  - Back pain is a complex phenomenon that goes beyond a simple medical diagnosis. The aetiology and chronification of back pain can be best described as an interaction between biological, psychological, and social processes. However, to date, multimodal prevention and intervention programs for back pain that target all three aetiological factors have demonstrated limited effectiveness. This lack of supportive evidence for multimodal programmes in the treatment of back pain could be due to the fact that few programs are suitable for long-term and unsupervised use in everyday life. Moreover, in combining the elements from various therapies, little attention has been paid to the mechanisms underlying the synergistic effects of the separate components. In this contribution, we will describe the development of a new multimodal intervention for back pain that set out to address these limitations. To this end, the biological elements of neuromuscular adaptation is supplemented with cognitive behavioral and psychophysiological techniques in an intervention that can be followed at home as well as in clinics, and that is suitable for all grades of pain. The efficacy of this intervention will be tested in a multicentric randomized controlled longitudinal trial (n = 714) at five time points over a period of 6 months. Here we will describe the development and the content of this new intervention.
KW  - Chronic pain
KW  - Cognitive behavioral therapy
KW  - Psychoeducation
KW  - Combined modality therapy
KW  - Sensorimotor training
Y1  - 2015
U6  - https://doi.org/10.1007/s00482-015-0044-y
SN  - 0932-433X
SN  - 1432-2129
VL  - 29
IS  - 6
SP  - 658
EP  - 663
PB  - Springer
CY  - New York
ER  - 
TY  - CHAP
A1  - Wippert, Pia-Maria
A1  - De Witt Huberts, Jessie
A1  - Honold, Jasmin
A1  - Holzmann, Caroline
A1  - Rector, Michael V.
A1  - Mayer, Frank
T1  - Chronic stress measurement methods and their comparability
T2  - Psychosomatic medicine
Y1  - 2014
SN  - 0033-3174
SN  - 1534-7796
VL  - 76
IS  - 3
SP  - A129
EP  - A129
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Puschmann, Anne-Katrin
A1  - Drießlein, David
A1  - Beck, Heidrun
A1  - Arampatzis, Adamantios
A1  - Moreno Catalá, Maria
A1  - Schiltenwolf, Marcus
A1  - Mayer, Frank
A1  - Wippert, Pia-Maria
T1  - Stress and Self-Efficacy as Long-Term Predictors for Chronic Low Back Pain
BT  - A Prospective Longitudinal Study
JF  - Journal of Pain Research
N2  - Purpose: Psychosocial variables are known risk factors for the development and chronification of low back pain (LBP). Psychosocial stress is one of these risk factors. Therefore, this study aims to identify the most important types of stress predicting LBP. Self-efficacy was included as a potential protective factor related to both, stress and pain.

Participants and Methods: This prospective observational study assessed n = 1071 subjects with low back pain over 2 years. Psychosocial stress was evaluated in a broad manner using instruments assessing perceived stress, stress experiences in work and social contexts, vital exhaustion and life-event stress. Further, self-efficacy and pain (characteristic pain intensity and disability) were assessed. Using least absolute shrinkage selection operator regression, important predictors of characteristic pain intensity and pain-related disability at 1-year and 2-years follow-up were analyzed.

Results: The final sample for the statistic procedure consisted of 588 subjects (age: 39.2 (± 13.4) years; baseline pain intensity: 27.8 (± 18.4); disability: 14.3 (± 17.9)). In the 1-year follow-up, the stress types “tendency to worry”, “social isolation”, “work discontent” as well as vital exhaustion and negative life events were identified as risk factors for both pain intensity and pain-related disability. Within the 2-years follow-up, Lasso models identified the stress types “tendency to worry”, “social isolation”, “social conflicts”, and “perceived long-term stress” as potential risk factors for both pain intensity and disability. Furthermore, “self-efficacy” (“internality”, “self-concept”) and “social externality” play a role in reducing pain-related disability.

Conclusion: Stress experiences in social and work-related contexts were identified as important risk factors for LBP 1 or 2 years in the future, even in subjects with low initial pain levels. Self-efficacy turned out to be a protective factor for pain development, especially in the long-term follow-up. Results suggest a differentiation of stress types in addressing psychosocial factors in research, prevention and therapy approaches.
KW  - low back pain
KW  - psychosocial risk factors
KW  - stress
KW  - self-efficacy
KW  - MiSpEx
Y1  - 2019
U6  - https://doi.org/10.2147/JPR.S223893
SN  - 1178-7090
VL  - 13
SP  - 613
EP  - 621
PB  - Dove Medical Press
CY  - Albany, Auckland
ER  - 
TY  - GEN
A1  - Wippert, Pia-Maria
A1  - Puschmann, Anne-Katrin
A1  - Schiltenwolf, Marcus
A1  - Wiebking, Christine
A1  - Mayer, Frank
T1  - BACK PAIN: THE STUDY OF MECHANISMS AND THE TRANSLATION IN INTERVENTIONS WITHIN THE MISPEX NETWORK
T2  - Psychosomatic medicine
Y1  - 2016
SN  - 0033-3174
SN  - 1534-7796
VL  - 78
SP  - A91
EP  - A91
PB  - Elsevier
CY  - Philadelphia
ER  - 
TY  - GEN
A1  - Mugele, Hendrik
A1  - Plummer, Ashley
A1  - Baritello, Omar
A1  - Towe, Maggie
A1  - Brecht, Pia
A1  - Mayer, Frank
T1  - Accuracy of training recommendations based on a treadmill multistage incremental exercise test
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - Competitive runners will occasionally undergo exercise in a laboratory setting to obtain predictive and prescriptive information regarding their performance. The present research aimed to assess whether the physiological demands of lab-based treadmill running (TM) can simulate that of over-ground (OG) running using a commonly used protocol. Fifteen healthy volunteers with a weekly mileage of ≥ 20 km over the past 6 months and treadmill experience participated in this cross-sectional study. Two stepwise incremental tests until volitional exhaustion was performed in a fixed order within one week in an Outpatient Clinic research laboratory and outdoor athletic track. Running velocity (IATspeed), heart rate (IATHR) and lactate concentration at the individual anaerobic threshold (IATbLa) were primary endpoints. Additionally, distance covered (DIST), maximal heart rate (HRmax), maximal blood lactate concentration (bLamax) and rate of perceived exertion (RPE) at IATspeed were analyzed. IATspeed, DIST and HRmax were not statistically significantly different between conditions, whereas bLamax and RPE at IATspeed showed statistical significance (p < 0.05). Apart from RPE at IATspeed, IATspeed, DIST, HRmax and bLamax strongly correlate between conditions (r = 0.815–0.988). High reliability between conditions provides strong evidence to suggest that running on a treadmill are physiologically comparable to that of OG and that training recommendations and be made with assurance.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 477 
KW  - individual anaerobic threshold
KW  - lactate threshold
KW  - soccer players
KW  - performance
KW  - validity
KW  - reliability
KW  - runners
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-419697
SN  - 1866-8364
IS  - 477
ER  - 
TY  - GEN
A1  - Appiah-Dwomoh, Edem Korkor
A1  - Müller, Steffen
A1  - Hadzic, Miralem
A1  - Mayer, Frank
T1  - Star Excursion Balance Test in young athletes with back pain
N2  - The Star Excursion Balance Test (SEBT) is effective in measuring dynamic postural control (DPC). This research aimed to determine whether DPC measured by the SEBT in young athletes (YA) with back pain (BP) is different from those without BP (NBP). 53 BP YA and 53 NBP YA matched for age, height, weight, training years, training sessions/week and training minutes/session were studied. Participants performed 4 practice trials after which 3 measurements in the anterior, posteromedial and posterolateral SEBT reach directions were recorded. Normalized reach distance was analyzed using the mean of all 3 measurements. There was no statistical significant difference (p > 0.05) between the reach distance of BP (87.2 ± 5.3, 82.4 ± 8.2, 78.7 ± 8.1) and NBP (87.8 ± 5.6, 82.4 ± 8.0, 80.0 ± 8.8) in the anterior, posteromedial and posterolateral directions respectively. DPC in YA with BP, as assessed by the SEBT, was not different from NBP YA.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 337 
KW  - young athletes
KW  - back pain
KW  - star excursion balance test
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-400441
ER  - 
TY  - GEN
A1  - Puschmann, Anne-Katrin
A1  - Drießlein, David
A1  - Beck, Heidrun
A1  - Arampatzis, Adamantios
A1  - Moreno Catalá, Maria
A1  - Schiltenwolf, Marcus
A1  - Mayer, Frank
A1  - Wippert, Pia-Maria
T1  - Stress and Self-Efficacy as Long-Term Predictors for Chronic Low Back Pain
BT  - A Prospective Longitudinal Study
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - Purpose: Psychosocial variables are known risk factors for the development and chronification of low back pain (LBP). Psychosocial stress is one of these risk factors. Therefore, this study aims to identify the most important types of stress predicting LBP. Self-efficacy was included as a potential protective factor related to both, stress and pain.

Participants and Methods: This prospective observational study assessed n = 1071 subjects with low back pain over 2 years. Psychosocial stress was evaluated in a broad manner using instruments assessing perceived stress, stress experiences in work and social contexts, vital exhaustion and life-event stress. Further, self-efficacy and pain (characteristic pain intensity and disability) were assessed. Using least absolute shrinkage selection operator regression, important predictors of characteristic pain intensity and pain-related disability at 1-year and 2-years follow-up were analyzed.

Results: The final sample for the statistic procedure consisted of 588 subjects (age: 39.2 (± 13.4) years; baseline pain intensity: 27.8 (± 18.4); disability: 14.3 (± 17.9)). In the 1-year follow-up, the stress types “tendency to worry”, “social isolation”, “work discontent” as well as vital exhaustion and negative life events were identified as risk factors for both pain intensity and pain-related disability. Within the 2-years follow-up, Lasso models identified the stress types “tendency to worry”, “social isolation”, “social conflicts”, and “perceived long-term stress” as potential risk factors for both pain intensity and disability. Furthermore, “self-efficacy” (“internality”, “self-concept”) and “social externality” play a role in reducing pain-related disability.

Conclusion: Stress experiences in social and work-related contexts were identified as important risk factors for LBP 1 or 2 years in the future, even in subjects with low initial pain levels. Self-efficacy turned out to be a protective factor for pain development, especially in the long-term follow-up. Results suggest a differentiation of stress types in addressing psychosocial factors in research, prevention and therapy approaches.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 617 
KW  - low back pain
KW  - psychosocial risk factors
KW  - stress
KW  - self-efficacy
KW  - MiSpEx
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-460134
SN  - 1866-8364
SP  - 613
EP  - 621
ER  - 
TY  - JOUR
A1  - Mueller, Steffen
A1  - Mueller, Juliane
A1  - Stoll, Josefine
A1  - Mayer, Frank
T1  - Effect of six-week resistance and sensorimotor training on trunk strength and stability in elite adolescent athletes
BT  - a randomized controlled pilot trial
JF  - Frontiers in physiology
N2  - Intervention in the form of core-specific stability exercises is evident to improve trunk stability. The purpose was to assess the effect of an additional 6 weeks sensorimotor or resistance training on maximum isokinetic trunk strength and response to sudden dynamic trunk loading (STL) in highly trained adolescent athletes. The study was conducted as a single-blind, 3-armed randomized controlled trial. Twenty-four adolescent athletes (14f/10 m, 16 +/- 1 yrs.;178 +/- 10 cm; 67 +/- 11 kg; training sessions/week 15 +/- 5; training h/week 22 +/- 8) were randomized into resistance training (RT; n = 7), sensorimotor training (SMT; n = 10), and control group (CG; n = 7). Athletes were instructed to perform standardized, center-based training for 6 weeks, two times per week, with a duration of 1 h each session. SMT consisted of four different core-specific sensorimotor exercises using instable surfaces. RT consisted of four trunk strength exercises using strength training machines, as well as an isokinetic dynamometer. All participants in the CG received an unspecific heart frequency controlled, ergometer-based endurance training (50 min at max. heart frequency of 130HF). For each athlete, each training session was documented in an individual training diary (e.g., level of SMT exercise; 1RM for strength exercise, pain). At baseline (M1) and after 6 weeks of intervention (M2), participants' maximum strength in trunk rotation (ROM:63 degrees) and flexion/extension (ROM:55 degrees) was tested on an isokinetic dynamometer (concentric/eccentric 30 degrees/s). STL was assessed in eccentric (30 degrees/s) mode with additional dynamometer-induced perturbation as a marker of core stability. Peak torque [Nm] was calculated as the main outcome. The primary outcome measurements (trunk rotation/extension peak torque: con, ecc, STL) were statistically analyzed by means of the two-factor repeated measures analysis of variance (alpha = 0.05). Out of 12 possible sessions, athletes participated between 8 and 9 sessions (SMT: 9 +/- 3; RT: 8 +/- 3; CG: 8 +/- 4). Regarding main outcomes of trunk performance, experimental groups showed no significant pre-post difference for maximum trunk strength testing as well as for perturbation compensation (p > 0.05). It is concluded, that future interventions should exceed 6 weeks duration with at least 2 sessions per week to induce enhanced trunk strength or compensatory response to sudden, high-intensity trunk loading in already highly trained adolescent athletes, regardless of training regime.
KW  - core
KW  - training intervention
KW  - trunk stability
KW  - exercise
KW  - perturbation
Y1  - 2022
U6  - https://doi.org/10.3389/fphys.2022.802315
SN  - 1664-042X
VL  - 13
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - GEN
A1  - Plummer, Ashley
A1  - Mugele, Hendrik
A1  - Steffen, Kathrin
A1  - Stoll, Josefine
A1  - Mayer, Frank
A1  - Müller, Juliane
T1  - General versus sports-specific injury prevention programs in athletes
BT  - A systematic review on the effects on performance
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - Introduction
Injury prevention programs (IPPs) are an inherent part of training in recreational and professional sports. Providing performance-enhancing benefits in addition to injury prevention may help adjust coaches and athletes’ attitudes towards implementation of injury prevention into daily routine. Conventional thinking by players and coaches alike seems to suggest that IPPs need to be specific to one’s sport to allow for performance enhancement. The systematic literature review aims to firstly determine the IPPs nature of exercises and whether they are specific to the sport or based on general conditioning. Secondly, can they demonstrate whether general, sports-specific or even mixed IPPs improve key performance indicators with the aim to better facilitate long-term implementation of these programs?

Methods
PubMed and Web of Science were electronically searched throughout March 2018. The inclusion criteria were randomized control trials, publication dates between Jan 2006 and Feb 2018, athletes (11–45 years), injury prevention programs and included predefined performance measures that could be categorized into balance, power, strength, speed/agility and endurance. The methodological quality of included articles was assessed with the Cochrane Collaboration assessment tools.

Results
Of 6619 initial findings, 22 studies met the inclusion criteria. In addition, reference lists unearthed a further 6 studies, making a total of 28. Nine studies used sports specific IPPs, eleven general and eight mixed prevention strategies. Overall, general programs ranged from 29–57% in their effectiveness across performance outcomes. Mixed IPPs improved in 80% balance outcomes but only 20–44% in others. Sports-specific programs led to larger scale improvements in balance (66%), power (83%), strength (75%), and speed/agility (62%).

Conclusion
Sports-specific IPPs have the strongest influence on most performance indices based on the significant improvement versus control groups. Other factors such as intensity, technical execution and compliance should be accounted for in future investigations in addition to exercise modality.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 591 
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-441131
SN  - 1866-8364
IS  - 591
ER  - 
TY  - GEN
A1  - Eichler, Sarah
A1  - Salzwedel, Annett
A1  - Rabe, Sophie
A1  - Mueller, Steffen
A1  - Mayer, Frank
A1  - Wochatz, Monique
A1  - Hadzic, Miralem
A1  - John, Michael
A1  - Wegscheider, Karl
A1  - Völler, Heinz
T1  - The Effectiveness of Telerehabilitation as a Supplement to Rehabilitation in Patients After Total Knee or Hip Replacement
BT  - Randomized Controlled Trial
T2  - Postprints der Universität Potsdam : Humanwissenschaftliche Reihe
N2  - Background: Telerehabilitation can contribute to the maintenance of successful rehabilitation regardless of location and time. The aim of this study was to investigate a specific three-month interactive telerehabilitation routine regarding its effectiveness in assisting patients with physical functionality and with returning to work compared to typical aftercare.

Objective: The aim of the study was to investigate a specific three-month interactive telerehabilitation with regard to effectiveness in functioning and return to work compared to usual aftercare.

Methods: From August 2016 to December 2017, 111 patients (mean 54.9 years old; SD 6.8; 54.3% female) with hip or knee replacement were enrolled in the randomized controlled trial. At discharge from inpatient rehabilitation and after three months, their distance in the 6-minute walk test was assessed as the primary endpoint. Other functional parameters, including health related quality of life, pain, and time to return to work, were secondary endpoints.

Results: Patients in the intervention group performed telerehabilitation for an average of 55.0 minutes (SD 9.2) per week. Adherence was high, at over 75%, until the 7th week of the three-month intervention phase. Almost all the patients and therapists used the communication options. Both the intervention group (average difference 88.3 m; SD 57.7; P=.95) and the control group (average difference 79.6 m; SD 48.7; P=.95) increased their distance in the 6-minute-walk-test. Improvements in other functional parameters, as well as in quality of life and pain, were achieved in both groups. The higher proportion of working patients in the intervention group (64.6%; P=.01) versus the control group (46.2%) is of note.

Conclusions: The effect of the investigated telerehabilitation therapy in patients following knee or hip replacement was equivalent to the usual aftercare in terms of functional testing, quality of life, and pain. Since a significantly higher return-to-work rate could be achieved, this therapy might be a promising supplement to established aftercare.
T3  - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 589 
KW  - telerehabilitation
KW  - home-based
KW  - total hip replacement
KW  - total knee replacement
KW  - exercise therapy
KW  - aftercare
KW  - rehabilitation
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-440965
SN  - 1866-8364
IS  - 589
ER  - 
TY  - JOUR
A1  - Martinez-Valdes, Eduardo Andrés
A1  - Negro, F.
A1  - Laine, C. M.
A1  - Falla, D.
A1  - Mayer, Frank
A1  - Farina, Dario
T1  - Tracking motor units longitudinally across experimental sessions with high-density surface electromyography
JF  - The Journal of Physiology
N2  - A new method is proposed for tracking individual motor units (MUs) across multiple experimental sessions on different days. The technique is based on a novel decomposition approach for high-density surface electromyography and was tested with two experimental studies for reliability and sensitivity. Experiment I (reliability): ten participants performed isometric knee extensions at 10, 30, 50 and 70% of their maximum voluntary contraction (MVC) force in three sessions, each separated by 1 week. Experiment II (sensitivity): seven participants performed 2 weeks of endurance training (cycling) and were tested pre-post intervention during isometric knee extensions at 10 and 30% MVC. The reliability (Experiment I) and sensitivity (Experiment II) of the measured MU properties were compared for the MUs tracked across sessions, with respect to all MUs identified in each session. In Experiment I, on average 38.3% and 40.1% of the identified MUs could be tracked across two sessions (1 and 2 weeks apart), for the vastus medialis and vastus lateralis, respectively. Moreover, the properties of the tracked MUs were more reliable across sessions than those of the full set of identified MUs (intra-class correlation coefficients ranged between 0.63-0.99 and 0.39-0.95, respectively). In Experiment II, similar to 40% of the MUs could be tracked before and after the training intervention and training-induced changes in MU conduction velocity had an effect size of 2.1 (tracked MUs) and 1.5 (group of all identified motor units). These results show the possibility of monitoring MU properties longitudinally to document the effect of interventions or the progression of neuromuscular disorders.
Y1  - 2016
U6  - https://doi.org/10.1113/JP273662
SN  - 0022-3751
SN  - 1469-7793
VL  - 595
SP  - 1479
EP  - 1496
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Mueller, Steffen
A1  - Engel, Tilman
A1  - Müller, Juliane
A1  - Stoll, Josefine
A1  - Baur, Heiner
A1  - Mayer, Frank
T1  - Sensorimotor exercises and enhanced trunk function
BT  - a randomized controlled trial
JF  - International journal of sports medicine
N2  - The aim of this study was to investigate the effect of a 6-week sensorimotor or resistance training on maximum trunk strength and response to sudden, high-intensity loading in athletes. Interventions showed no significant difference for maximum strength in concentric and eccentric testing (p>0.05). For perturbation compensation, higher peak torque response following SMT (Extension: +24Nm 95%CI +/- 19Nm; Rotation: + 19Nm 95%CI +/- 13Nm) and RT (Extension: +35Nm 95%CI +/- 16Nm; Rotation: +5Nm 95%CI +/- 4Nm) compared to CG (Extension: -4Nm 95%CI +/- 16Nm; Rotation: -2Nm 95%CI +/- 4Nm) was present (p<0.05).
KW  - core
KW  - training intervention
KW  - prevention
KW  - perturbation
KW  - MiSpEx*
Y1  - 2018
U6  - https://doi.org/10.1055/a-0592-7286
SN  - 0172-4622
SN  - 1439-3964
VL  - 39
IS  - 7
SP  - 555
EP  - 563
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Müller, Juliane
A1  - Stoll, Josefine
A1  - Mueller, Steffen
A1  - Mayer, Frank
T1  - Dose-response relationship of core-specific sensorimotor interventions in healthy, well-trained participants
BT  - study protocol for a (MiSpEx) randomized controlled trial
JF  - Trials
N2  - Background: Core-specific sensorimotor exercises are proven to enhance neuromuscular activity of the trunk, improve athletic performance and prevent back pain. However, the dose-response relationship and, therefore, the dose required to improve trunk function is still under debate. The purpose of the present trial will be to compare four different intervention strategies of sensorimotor exercises that will result in improved trunk function. Discussion: The results of the study will be clinically relevant, not only for researchers but also for (sports) therapists, physicians, coaches, athletes and the general population who have the aim of improving trunk function.
KW  - Sensorimotor training
KW  - Perturbation
KW  - Exercise
KW  - MiSpEx
Y1  - 2018
U6  - https://doi.org/10.1186/s13063-018-2799-9
SN  - 1745-6215
VL  - 19
PB  - BMC
CY  - London
ER  - 
TY  - GEN
A1  - Pérez Chaparro, Camilo Germán Alberto
A1  - Mayer, Frank
A1  - Beckendorf, Claudia
T1  - Cardiovascular drift response over two different constant-load exercises in healthy non-athletes
BT  - case study
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
N2  - Cardiovascular drift (CV-d) is a steady increase in heart rate (HR) over time while performing constant load moderate intensity exercise (CME) > 20 min. CV-d presents problems for the prescription of exercise intensity by means of HR, because the work rate (WR) during exercise must be adjusted to maintain target HR, thus disturbing the intended effect of the exercise intervention. It has been shown that the increase in HR during CME is due to changes in WR and not to CV-d.
Y1  - 2019
U6  - https://doi.org/10.1249/01.mss.0000561495.15163.50
SN  - 0195-9131
SN  - 1530-0315
VL  - 51
IS  - 6
SP  - 329
EP  - 329
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Appiah-Dwomoh, Edem Korkor
A1  - Müller, Steffen
A1  - Mayer, Frank
T1  - Is there an association between variables of static and dynamic postural control in adolescent athletes with back pain?
T1  - Gibt es einen Zusammenhang zwischen Variablen der statischen und dynamischen posturalen Kontrolle bei Nachwuchsathleten mit Rückenschmerzen?
JF  - German Journal of Exercise and Sport Research
N2  - An association between static and dynamic postural control exists in adults with back pain. We aimed to determine whether this association also exists in adolescent athletes with the same condition. In all, 128 athletes with and without back pain performed three measurements of 15s of static (one-legged stance) and dynamic (star excursion balance test) postural control tests. All subjects and amatched subgroup of athletes with and without back pain were analyzed. The smallest center of pressure mediolateral and anterior-posterior displacements (mm) and normalized highest reach distance were the outcome measures. No association was found between variables of the static and dynamic tests for all subjects and the matched group with and without back pain. The control of static and dynamic posture in adolescent athletes with and without back pain might not be related.
N2  - Bei Erwachsenen mit Rückenschmerzen besteht ein Zusammenhang zwischen statischer und dynamischer posturaler Kontrolle. Ziel der Studie war es zu untersuchen, ob dieser Zusammenhang auch bei Nachwuchsathleten mit Rückenschmerzen nachweisbar ist. Insgesamt 128 Nachwuchsathleten mit oder ohne Rückenschmerzen führten je 3 Messungen à 15 s eines statischen (einbeiniger Standtest) bzw. dynamischen („star excursion balance test“ [SEBT]) posturalen Kontrolltests durch. In die Auswertung wurden sowohl die gesamte Stichprobe als auch eine gematchte Untergruppe einbezogen. Zielparameter waren der kleinste mediolaterale und anterior-posteriore Schwankungsweg im Einbeinstand (mm) und die normierte maximal erreichte Distanz im SEBT. Es wurden keine Zusammenhänge zwischen Variablen der statischen und dynamischen Tests für alle Studienteilnehmer und der gematchten Untergruppe mit und ohne Rückenschmerzen festgestellt. Obwohl ein Zusammenhang zwischen statischer und dynamischer posturaler Kontrolle angenommen wird, konnte dieser bei Nachwuchsathleten mit oder ohne Rückenschmerzen nicht nachgewiesen werden.
KW  - Postural control
KW  - Adolescent athletes
KW  - Back pain
KW  - One-legged stance
KW  - Star excursion balance test
KW  - Posturale Kontrolle
KW  - Nachwuchsathleten
KW  - Rückenschmerzen
KW  - Einbeiniger Standtest
Y1  - 2019
U6  - https://doi.org/10.1007/s12662-019-00573-6
SN  - 2509-3142
SN  - 2509-3150
VL  - 49
IS  - 2
SP  - 150
EP  - 155
PB  - Springer
CY  - New York
ER  - 
TY  - GEN
A1  - Schraplau, Anne
A1  - Sonnenburg, Dominik
A1  - Wochatz, Monique
A1  - Engel, Tilman
A1  - Schomöller, Anne
A1  - Risch, Lucie
A1  - Kaplick, Hannes
A1  - Mayer, Frank
T1  - Characterization of muscle damage and inflammation following repeated maximal eccentric loading of the trunk
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
N2  - Eccentric exercises (ECC) induce reversible muscle damage, delayed-onset muscle soreness and an inflammatory reaction that is often followed by a systemic anti-inflammatory response. Thus, ECC might be beneficial for treatment of metabolic disorders which are frequently accompanied by a low-grade systemic inflammation. However, extent and time course of a systemic immune response after repeated ECC bouts are poorly characterized.
PURPOSE: To analyze the (anti-)inflammatory response after repeated ECC loading of the trunk.
METHODS: Ten healthy participants (33 ± 6 y; 173 ± 14 cm; 74 ± 16 kg) performed three isokinetic strength measurements of the trunk (concentric (CON), ECC1, ECC2, each 2 wks apart; flexion/extension, velocity 60°/s, 120s MVC). Pre- and 4, 24, 48, 72, 168h post-exercise, muscle soreness (numeric rating scale, NRS) was assessed and blood samples were taken and analyzed [Creatine kinase (CK), C-reactive protein (CRP), Interleukin-6 (IL-6), IL-10, Tumor necrosis factor-α (TNF-α)]. Statistics were done by Friedman‘s test with Dunn‘s post hoc test (α=.05).
RESULTS: Mean peak torque was higher during ECC1 (319 ± 142 Nm) than during CON (268 ± 108 Nm; p<.05) and not different between ECC1 and ECC2 (297 ± 126 Nm; p>.05). Markers of muscle damage (peaks post-ECC1: NRS 48h, 4.4±2.9; CK 72h, 14407 ± 19991 U/l) were higher after ECC1 than after CON and ECC2 (p<.05). The responses over 72h (stated as Area under the Curve, AUC) were abolished after ECC2 compared to ECC1 (p<.05) indicating the presence of the repeated bout effect. CRP levels were not changed. IL-6 levels increased 2-fold post-ECC1 (pre: 0.5 ± 0.4 vs. 72h: 1.0 ± 0.8 pg/ml). The IL-6 response was enhanced after ECC1 (AUC 61 ± 37 pg/ml*72h) compared to CON (AUC 33 ± 31 pg/ml*72h; p<.05). After ECC2, the IL-6 response (AUC 43 ± 25 pg/ml*72h) remained lower than post-ECC1, but the difference was not statistically significant. Serum levels of TNF-α and of the anti-inflammatory cytokine IL-10 were below detection limits. Overall, markers of muscle damage and immune response showed high inter-individual variability.
CONCLUSION: Despite maximal ECC loading of a large muscle group, no anti-inflammatory and just weak inflammatory responses were detected in healthy adults. Whether ECC elicits a different reaction in inflammatory clinical conditions is unclear.
Y1  - 2020
U6  - https://doi.org/10.1249/01.mss.0000679532.65880.af
SN  - 0195-9131
SN  - 1530-0315
VL  - 52
IS  - 7S
SP  - 497
EP  - 497
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Engel, Tilman
A1  - Schraplau, Anne
A1  - Wochatz, Monique
A1  - Kopinski, Stephan
A1  - Sonnenburg, Dominik
A1  - Schomöller, Anne
A1  - Risch, Lucie
A1  - Kaplick, Hannes
A1  - Mayer, Frank
T1  - Feasability of An Eccentric Isokinetic Protocol to Induce Trunk Muscle Damage: A Pilot Study
JF  - Sports Medicine International Open
N2  - Eccentric exercise is discussed as a treatment option for clinical populations, but specific responses in terms of muscle damage and systemic inflammation after repeated loading of large muscle groups have not been conclusively characterized. Therefore, this study tested the feasibility of an isokinetic protocol for repeated maximum eccentric loading of the trunk muscles. Nine asymptomatic participants (5 f/4 m; 34±6 yrs; 175±13 cm; 76±17 kg) performed three isokinetic 2-minute all-out trunk strength tests (1x concentric (CON), 2x eccentric (ECC1, ECC2), 2 weeks apart; flexion/extension, 60°/s, ROM 55°). Outcomes were peak torque, torque decline, total work, and indicators of muscle damage and inflammation (over 168 h). Statistics were done using the Friedman test (Dunn’s post-test). For ECC1 and ECC2, peak torque and total work were increased and torque decline reduced compared to CON. Repeated ECC bouts yielded unaltered torque and work outcomes. Muscle damage markers were highest after ECC1 (soreness 48 h, creatine kinase 72 h; p<0.05). Their overall responses (area under the curve) were abolished post-ECC2 compared to post-ECC1 (p<0.05). Interleukin-6 was higher post-ECC1 than CON, and attenuated post-ECC2 (p>0.05). Interleukin-10 and tumor necrosis factor-α were not detectable. All markers showed high inter-individual variability. The protocol was feasible to induce muscle damage indicators after exercising a large muscle group, but the pilot results indicated only weak systemic inflammatory responses in asymptomatic adults.
KW  - exercise
KW  - eccentric
KW  - muscle fatigue
KW  - trunk muscles
KW  - isokinetics
KW  - repeated bout effect
KW  - inflammation
KW  - exercise induced muscle damage
KW  - interleukin-6
KW  - internleukin-10
KW  - tumor necrosis factor-α
Y1  - 2021
U6  - https://doi.org/10.1055/a-1757-6724
SN  - 2367-1890
VL  - 6
SP  - E9
EP  - E17
PB  - Thieme
CY  - Stuttgart
ET  - 1
ER  - 
TY  - JOUR
A1  - Schomöller, Anne
A1  - Weis, Katharina
A1  - von Barby, Reena
A1  - Hübler, Axel
A1  - Mayer, Frank
A1  - Erler, Thomas
T1  - Restless legs syndrome in childhood and adolescence
BT  - Applicability of aquestionnaire designed to assess disease-related symptoms
JF  - Somnologie : Schlafforschung und Schlafmedizin ; Organ der Deutschen Gesellschaft für Schlafforschung und Schlafmedizin (DGSM)
KW  - Sleep
KW  - Child
KW  - Adolescent
KW  - Questionnaires
KW  - Diagnostic techniques and procedures
KW  - RLS
Y1  - 2019
U6  - https://doi.org/10.1007/s11818-018-0188-y
SN  - 1432-9123
SN  - 1439-054X
VL  - 23
IS  - 2
SP  - 104
EP  - 108
PB  - Springer
CY  - Cham
ER  - 
TY  - GEN
A1  - Schomöller, Anne
A1  - Risch, Lucie
A1  - Kaplick, Hannes
A1  - Schraplau, Anne
A1  - Wochatz, Monique
A1  - Engel, Tilman
A1  - Sonnenburg, Dominik
A1  - Mayer, Frank
T1  - Changes in paraspinal muscle T2 times and creatine kinase after a bout of eccentric exercise
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
N2  - Eccentric (ECC) exercises might cause muscle damage, characterized by delayed-onset muscle soreness, elevated creatine kinase (CK) levels and local muscle oedema, shown by elevated T2 times in magnet resonance imaging (MRI) scans. Previous research suggests a high inter-individual difference regarding these systemic and local responses to eccentric workload. PURPOSE: To analyze ECC exercise-induced muscle damage in lumbar paraspinal muscles assessed via MRI. METHODS: Ten participants (3f/7m; 33±6y; 174±8cm; 71±12kg) were included in the study. Quantitative paraspinal muscle constitution of M. erector spinae and M. multifidius were assessed in supine position before and 72h after an intense eccentric trunk exercise bout in a mobile 1.5 tesla MRI device. MRI scans were recorded on spinal level L3 (T2-weighted TSE echo sequences, 11 slices, 2mm slice thickness, 3mm gap, echo times: 20, 40, 60, 80, 100ms, TR time: 2500ms). Muscle T2 times were calculated for manually traced regions of interest of the respective muscles with an imaging software. The exercise protocol was performed in an isokinetic device and consisted of 120sec alternating ECC trunk flexion-extension with maximal effort. Venous blood samples were taken before and 72h after the ECC exercise. Descriptive statistics (mean±SD) and t-testing for pre-post ECC exercises were performed. RESULTS: T2 times increased from pre- to post-ECC MRI measurements from 55±3ms to 79±28ms in M. erector spinae and from 62±5ms to 78±24ms in M. multifidius (p<0.001). CK increased from 126±97 U/L to 1447±20579 U/L. High SDs of T2 time and CK in post-ECC measures could be due to inter-individual reactions to ECC exercises. 3 participants showed high local and systemic reactions (HR) with T2 time increases of 120±24% (M. erector spinae) and 73±50% (M. multifidius). In comparison, the remaining 7 participants showed increases of 11±12% (M. erector spinae) and 7±9% (M. multifidius) in T2 time. Mean CK increased 9.5-fold in the 3 HR subjects compared with the remaining 7 subjects. CONCLUSIONS: The 120sec maximal ECC trunk flexion-extension protocol induced high amounts of muscle damage in 3 participants. Moderate to low responses were found in the remaining 7 subjects, assuming that inter-individual predictors play a role regarding physiological responses to ECC workload.
Y1  - 2020
U6  - https://doi.org/10.1249/01.mss.0000685648.68626.f1
SN  - 0195-9131
SN  - 1530-0315
SN  - 0025-7990
VL  - 52
IS  - 17
SP  - 929
EP  - 929
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Schomöller, Anne
A1  - Risch, Lucie
A1  - Kaplick, Hannes
A1  - Wochatz, Monique
A1  - Engel, Tilman
A1  - Schraplau, Anne
A1  - Sonnenburg, Dominik
A1  - Huppertz, Alexander
A1  - Mayer, Frank
T1  - Inter-rater and inter-session reliability of lumbar paraspinal muscle composition in a mobile MRI device
JF  - BJR : an international journal of radiology, radiation oncology and all related sciences / British Institute of Radiology
N2  - Objective: To assess the reliability of measurements of paraspinal muscle transverse relaxation times (T2 times) between two observers and within one observer on different time points. <br /> Methods: 14 participants (9f/5m, 33 +/- 5 years, 176 +/- 10 cm, 73 +/- 12 kg) underwent 2 consecutive MRI scans (M1,M2) on the same day, followed by 1 MRI scan 13-14 days later (M3) in a mobile 1.5 Tesla MRI. T2 times were calculated in T-2 weighted turbo spin- echo-sequences at the spinal level of the third lumbar vertebrae (11 slices, 2 mm slice thickness, 1 mm interslice gap, echo times: 20, 40, 60, 80, 100 ms) for M. erector spinae (ES) and M. multifidius (MF). The following reliability parameter were calculated for the agreement of T2 times between two different investigators (OBS1 & OBS2) on the same MRI (inter rater reliability, IR) and by one investigator between different MRI of the same participant (intersession variability, IS): Test-Retest Variability (TRV, Differences/Mean*100); Coefficient of Variation (CV, Standard deviation/Mean*100); Bland-Altman Analysis (systematic bias = Mean of the Differences; Upper/Lower Limits of Agreement = Bias+/-1.96*SD); Intraclass Correlation Coefficient 3.1 (ICC) with absolute agreement, as well as its 95% confidence interval. <br /> Results: Mean TRV for IR was 2.6% for ES and 4.2% for MF. Mean TRV for IS was 3.5% (ES) and 5.1% (MF). Mean CV for IR was 1.9 (ES) and 3.0 (MF). Mean CV for IS was 2.5% (ES) and 3.6% (MF). A systematic bias of 1.3 ms (ES) and 2.1 ms (MF) were detected for IR and a systematic bias of 0.4 ms (ES) and 0.07 ms (MF) for IS. ICC for IR was 0.94 (ES) and 0.87 (MF). ICC for IS was 0.88 (ES) and 0.82 (MF). <br /> Conclusion: Reliable assessment of paraspinal muscle T2 time justifies its use for scientific purposes. The applied technique could be recommended to use for future studies that aim to assess changes of T2 times, e.g. after an intense bout of eccentric exercises.
Y1  - 2021
U6  - https://doi.org/10.1259/bjr.20210141
SN  - 0007-1285
SN  - 1748-880X
VL  - 94
IS  - 1127
PB  - Wiley
CY  - Bognor Regis
ER  - 
TY  - JOUR
A1  - Khajooei, Mina
A1  - Wochatz, Monique
A1  - Baritello, Omar
A1  - Mayer, Frank
T1  - Effects of shoes on children’s fundamental motor
skills performance
JF  - Footwear science : official journal of the Footwear Biomechanics Group
N2  - Progression or impediment of fundamental motor skills performance (FMSP) in children depends on internal and environmental factors. Shoes as an environmental constraint are believed to affect these movements as children showed to perform qualitatively better with sports shoes than flip-flop sandals. However, locomotor performance assessments based on biomechanical variables are limited. Therefore, the objective of this experiment was to assess the biomechanical effects of wearing shoes while performing fundamental motor skills in children. Barefoot and shod conditions were tested in healthy children between the age of 4 and 7 years. They were asked to perform basic and advanced motor skills including double-leg stance, horizontal jumps, walking as well as counter-movement jumps, single-leg stance and sprinting. Postural control and ground reaction data were measured with two embedded force plates. A 3D motion capture system was used to analyse the spatiotemporal parameters of walking and sprinting. Findings showed that the parameters of single- and double-leg stance, horizontal and counter-movement jump did not differ between barefoot and shod conditions. Most of the spatiotemporal variables including cadence, stride length, stride time, and contact time of walking and sprinting were statistically different between the barefoot and shod conditions. Consequently, tested shoes did not change performance and biomechanics of postural control and jumping tasks; however, the spatiotemporal gait parameters indicate changes in walking and sprinting characteristics with shoes in children.
KW  - Spatiotemporal
KW  - kinetics
KW  - jumping
KW  - stability
KW  - gait
Y1  - 2019
U6  - https://doi.org/10.1080/19424280.2019.1696895
SN  - 1942-4280
SN  - 1942-4299
VL  - 12
IS  - 1
SP  - 55
EP  - 62
PB  - Taylor & Francis
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Brecht, Pia
A1  - Beckendorf, Claudia
A1  - Mayer, Frank
T1  - Cardiac remodeling in child and adolescent athletes in association with sport discipline and sex
JF  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
N2  - Continuous high training loads are associated with structural cardiac adaptations and development of an athletic heart in adult athletes, especially in sport disciplines with high dynamic training components. In child and adolescent athletes these effects are increasingly reported. However, study populations are still very small.
Y1  - 2020
U6  - https://doi.org/10.1249/01.mss.0000679076.53908.d0
SN  - 0195-9131
SN  - 1530-0315
VL  - 52
IS  - 17
SP  - 472
EP  - 473
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Müller, Steffen
A1  - Stoll, Josefine
A1  - Mueller, Juliane
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Trunk Muscle Activity during Drop Jump Performance in Adolescent Athletes with Back Pain
JF  - Frontiers in physiology
N2  - In the context of back pain, great emphasis has been placed on the importance of trunk stability, especially in situations requiring compensation of repetitive, intense loading induced during high-performance activities, e.g., jumping or landing. This study aims to evaluate trunk muscle activity during drop jump in adolescent athletes with back pain (BP) compared to athletes without back pain (NBP). Eleven adolescent athletes suffering back pain (BP: m/f: n = 4/7; 15.9 +/- 1.3 y; 176 +/- 11 cm; 68 +/- 11 kg; 12.4 +/- 10.5 h/we training) and 11 matched athletes without back pain (NBP: m/f: n = 4/7; 15.5 +/- 1.3 y; 174 +/- 7 cm; 67 +/- 8 kg; 14.9 +/- 9.5 h/we training) were evaluated. Subjects conducted 3 drop jumps onto a force plate (ground reaction force). Bilateral 12-lead SEMG (surface Electromyography) was applied to assess trunk muscle activity. Ground contact time [ms], maximum vertical jump force [N], jump time [ms] and the jump performance index [m/s] were calculated for drop jumps. SEMG amplitudes (RMS: root mean square [%]) for all 12 single muscles were normalized toMIVC (maximum isometric voluntary contraction) and analyzed in 4 time windows (100 ms pre- and 200 ms post-initial ground contact, 100 ms pre- and 200 ms post-landing) as outcome variables. In addition, muscles were grouped and analyzed in ventral and dorsal muscles, as well as straight and transverse trunk muscles. Drop jump ground reaction force variables did not differ between NBP and BP (p > 0.05). Mm obliquus externus and internus abdominis presented higher SEMG amplitudes (1.3-1.9-fold) for BP (p < 0.05). Mm rectus abdominis, erector spinae thoracic/lumbar and latissimus dorsi did not differ (p > 0.05). The muscle group analysis over the whole jumping cycle showed statistically significantly higher SEMG amplitudes for BP in the ventral (p = 0.031) and transverse muscles (p = 0.020) compared to NBP. Higher activity of transverse, but not straight, trunk muscles might indicate a specific compensation strategy to support trunk stability in athletes with back pain during drop jumps. Therefore, exercises favoring the transverse trunk muscles could be recommended for back pain treatment.
KW  - SEMG-pattern
KW  - back pain
KW  - pre-activity
KW  - drop jump
KW  - neuromuscular
KW  - trunk
KW  - performance
KW  - young athletes
Y1  - 2017
U6  - https://doi.org/10.3389/fphys.2017.00274
SN  - 1664-042X
VL  - 8
SP  - 124
EP  - 132
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Cassel, Michael
A1  - Carlsohn, Anja
A1  - Fröhlich, Katja
A1  - John, Mareike
A1  - Riegels, N.
A1  - Mayer, Frank
T1  - Tendon Adaptation to Sport-specific Loading in Adolescent Athletes
JF  - International journal of sports medicine
N2  - Tendon adaptation due to mechanical loading is controversially discussed. However, data concerning the development of tendon thickness in adolescent athletes is sparse. The purpose of this study was to examine possible differences in Achilles (AT) and patellar tendon (PT) thickness in adolescent athletes while considering age, gender and sport-specific loading. In 500 adolescent competitive athletes of 16 different sports and 40 recreational controls both ATs and PTs were sonographically measured. Subjects were divided into 2 age groups (< 13; &#8805; 13 years) and 6 sport type categories (ball, combat, and water sports, combined disciplines, cycling, controls). In addition, 3 risk groups (low, moderate, high) were created according to the athlete’s risk of developing tendinopathy. AT and PT thickness did not significantly differ between age groups (AT/PT:<13: 5.4±0.7 mm/3.6±0.5 mm;&#8805;13: 5.3±0.7 mm/3.6±0.5 mm). In both age groups males presented higher tendon thickness than females (p<0.001). AT thickness was highest in ball sports/cyclists and lowest in controls (p&#8804;0.002). PT thickness was greatest in water sports and lowest in controls (p=0.02). High risk athletes presented slightly higher AT thickness compared to the low risk group (p=0.03). Increased AT and PT thickness in certain sport types compared to controls supports the hypothesis of structural tendon adaptation due to sport-specific loading.
KW  - achilles and patellar tendon
KW  - training adaptation
KW  - tendon thickness
KW  - standard values
KW  - sonography
Y1  - 2016
U6  - https://doi.org/10.1055/s-0035-1559772
SN  - 0172-4622
SN  - 1439-3964
VL  - 37
SP  - 159
EP  - 164
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Bisi-Balogun, Adebisi
A1  - Cassel, Michael
A1  - Mayer, Frank
T1  - Reliability of Various Measurement Stations for Determining Plantar Fascia Thickness and Echogenicity
JF  - Diagnostics : open access journal
N2  - This study aimed to determine the relative and absolute reliability of ultrasound (US) measurements of the thickness and echogenicity of the plantar fascia (PF) at different measurement stations along its length using a standardized protocol. Twelve healthy subjects (24 feet) were enrolled. The PF was imaged in the longitudinal plane. Subjects were assessed twice to evaluate the intra-rater reliability. A quantitative evaluation of the thickness and echogenicity of the plantar fascia was performed using Image J, a digital image analysis and viewer software. A sonography evaluation of the thickness and echogenicity of the PF showed a high relative reliability with an Intra class correlation coefficient of 0.88 at all measurement stations. However, the measurement stations for both the PF thickness and echogenicity which showed the highest intraclass correlation coefficient (ICCs) did not have the highest absolute reliability. Compared to other measurement stations, measuring the PF thickness at 3 cm distal and the echogenicity at a region of interest 1 cm to 2 cm distal from its insertion at the medial calcaneal tubercle showed the highest absolute reliability with the least systematic bias and random error. Also, the reliability was higher using a mean of three measurements compared to one measurement. To reduce discrepancies in the interpretation of the thickness and echogenicity measurements of the PF, the absolute reliability of the different measurement stations should be considered in clinical practice and research rather than the relative reliability with the ICC.
KW  - plantar fascia
KW  - reliability
KW  - sonography
KW  - musculoskeletal
Y1  - 2016
U6  - https://doi.org/10.3390/diagnostics6020015
SN  - 2075-4418
VL  - 6
SP  - 506
EP  - 519
PB  - MDPI
CY  - Basel
ER  - 
TY  - GEN
A1  - Joost, Theresa Anna
A1  - Brecht, Pia
A1  - Mayer, Frank
A1  - Cassel, Michael
T1  - Feasibility of open low-field MRI measurements in adolescent athletes with spondylolisthesis
T2  - Medicine and science in sports and exercise : official journal of the American College of Sports Medicine
N2  - PURPOSE: To determine the feasibility of upright compared to supine MRI measurements to determine characteristics of the lumbar spine in AA with spondylolisthesis.
METHODS: Ten AA (n=10; m/f: 4/6; 14.5±1.7y; 163±7cm; 52±8kg) from various sports, diagnosed with spondylolisthesis grade I-II Meyerding confirmed by x-ray in standing lateral view, were included. Open low-field MRI images (0.25 Tesla) in upright (82°) and supine (0°) position were evaluated by two observers. Medical imaging software was used to measure the anterior translation (AT, mm), lumbosacral joint angle (LSJA, °) and lordosis angle (LA, °). Reliability was analyzed by the intra-rater correlation coefficient (ICC) and standard error of measurements (SEM).
RESULTS: Due to motion artifacts during upright position, measures of three participants had to be excluded. Between observers, AT ranged from 4.2±2.7mm to 5.5±1.9mm (ICC=0.94, SEM=0.6mm) in upright and from 4.9±2.4mm to 5.9±3.0mm (ICC=0.89, SEM=0.9mm) in supine position. LSJA varied from 5.1±2.2° to 7.3±1.5° (ICC=0.54, SEM=1.5°) in upright and from 9.8±2.5° to 10±2.4° (ICC=0.73, SEM=1.1°) in supine position. LA differed from 58.8±14.6° to 61.9±6° (ICC=0.94, SEM=1.19°) in upright and from 51.9±11.7° to 52.6±11.1° (ICC=0.98, SEM=1.59°) in supine position.
CONCLUSIONS: Determination of AT and LA showed good to excellent reliability in both, upright and supine position. In contrast, reliability of LSJA had only moderate to good correlation
between observers and should therefore be interpreted with caution. However, motion artifacts should be taken into consideration during upright imaging procedures.
Y1  - 2020
U6  - https://doi.org/10.1249/01.mss.0000683832.74059.9d
SN  - 0195-9131
SN  - 1530-0315
VL  - 52
IS  - 17
SP  - 790
EP  - 790
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  - 
TY  - JOUR
A1  - Rector, Michael V.
A1  - Intziegianni, Konstantina
A1  - Müller, Steffen
A1  - Mayer, Frank
A1  - Cassel, Michael
T1  - Reproducibility of an ankle joint rotation correction method for assessment of Achilles tendon elongation
JF  - Isokinetics and exercise science : official journal of the European Isokinetic Society
N2  - BACKGROUND: The Achilles tendon (AT) requires optimal material and mechanical properties to function properly. Calculation of these properties depends on accurate measurement of input parameters (i.e. tendon elongation). However, the measurement of AT elongation with ultrasound during maximum voluntary isometric contraction (MVIC) is overestimated by ankle joint rotation (AJR). Methods to correct the influence of this rotation on AT elongation exist, yet their reproducibility in clinical settings is unknown. OBJECTIVE: To evaluate the test-retest reproducibility of AT elongation during MVIC after AJR correction. METHODS: Ten participants attended test and retest measurements where they performed plantar-flexion MVIC on a dynamometer. Simultaneously, ultrasound recorded AT elongation as the displacement of the medial gastrocnemius-myotendinous junction, while an electrogoniometer measured AJR. The ankle was then passively rotated to the AJR achieved during MVIC and AT elongation again determined. Elongation was corrected by subtracting this passive AT elongation from the total AT elongation during MVIC. Reproducibility was evaluated using ICC (2.1), test-retest variability (TRV, %), Bland-Altman analyses (Bias +/- LoA [1.96*SD]) and standard error of the measurement (SEM). RESULTS: Corrected AT elongation reproducibility exhibited an ICC = 0.79, SEM = 0.2 cm and TRV = 20 +/- 19%. Bias +/- LoA were determined to be 0.0 +/- 0.8 cm. CONCLUSIONS: Using this ultrasound and electrogoniometer-based method, corrected AT elongation can be assessed reproducibly.
KW  - Ultrasonography
KW  - Achilles tendon
KW  - reproducibility
KW  - isokinetic
KW  - ankle joint rotation
Y1  - 2017
U6  - https://doi.org/10.3233/IES-160644
SN  - 0959-3020
SN  - 1878-5913
VL  - 25
IS  - 1
SP  - 47
EP  - 52
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Wippert, Pia-Maria
A1  - Niederer, Daniel
A1  - Drießlein, David
A1  - Beck, Heidrun
A1  - Banzer, Winfried Eberhard
A1  - Schneider, Christian
A1  - Schiltenwolf, Marcus
A1  - Mayer, Frank
T1  - Psychosocial Moderators and Mediators of Sensorimotor Exercise in Low Back Pain: A Randomized Multicenter Controlled Trial
JF  - Frontiers in Psychiatry
N2  - The effects of exercise interventions on unspecific chronic low back pain (CLBP) have been investigated in many studies, but the results are inconclusive regarding exercise types, efficiency, and sustainability. This may be because the influence of psychosocial factors on exercise induced adaptation regarding CLBP is neglected. Therefore, this study assessed psychosocial characteristics, which moderate and mediate the effects of sensorimotor exercise on LBP. A single-blind 3-arm multicenter randomized controlled trial was conducted for 12-weeks. Three exercise groups, sensorimotor exercise (SMT), sensorimotor and behavioral training (SMT-BT), and regular routines (CG) were randomly assigned to 662 volunteers. Primary outcomes (pain intensity and disability) and psychosocial characteristics were assessed at baseline (M1) and follow-up (3/6/12/24 weeks, M2-M5). Multiple regression models were used to analyze whether psychosocial characteristics are moderators of the relationship between exercise and pain, meaning that psychosocial factors and exercise interact. Causal mediation analysis were conducted to analyze, whether psychosocial characteristics mediate the exercise effect on pain. A total of 453 participants with intermittent pain (mean age = 39.5 ± 12.2 years, f = 62%) completed the training. It was shown, that depressive symptomatology (at M4, M5), vital exhaustion (at M4), and perceived social support (at M5) are significant moderators of the relationship between exercise and the reduction of pain intensity. Further depressive mood (at M4), social-satisfaction (at M4), and anxiety (at M5 SMT) significantly moderate the exercise effect on pain disability. The amount of moderation was of clinical relevance. In contrast, there were no psychosocial variables which mediated exercise effects on pain. In conclusion it was shown, that psychosocial variables can be moderators in the relationship between sensorimotor exercise induced adaptation on CLBP which may explain conflicting results in the past regarding the merit of exercise interventions in CLBP. Results suggest further an early identification of psychosocial risk factors by diagnostic tools, which may essential support the planning of personalized exercise therapy.

Level of Evidence: Level I.

Clinical Trial Registration: DRKS00004977, LOE: I, MiSpEx: grant-number: 080102A/11-14. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00004977.
KW  - low-back-pain
KW  - motor-control-exercise
KW  - multidisciplinary-therapy
KW  - MiSpEx-network
KW  - yellow flags
Y1  - 2021
U6  - https://doi.org/10.3389/fpsyt.2021.629474
SN  - 1664-0640
VL  - 12
SP  - 1
EP  - 16
PB  - Frontiers Research Foundation
CY  - Lausanne, Schweiz
ER  - 
TY  - GEN
A1  - De Witt Huberts, Jessie
A1  - Niederer, Daniel
A1  - Wippert, Pia-Maria
A1  - Mayer, Frank
T1  - The effects of a new practical and synergetic multimodal treatment for chronic back pain on pain-related cognitions and wellbeing
T2  - Psychosomatic medicine
Y1  - 2017
SN  - 0033-3174
SN  - 1534-7796
VL  - 79
IS  - 4
SP  - A22
EP  - A23
PB  - Lippincott Williams & Wilkins
CY  - Philadelphia
ER  -