@article{WochatzTilgnerMuelleretal.2019,
author = {Wochatz, Monique and Tilgner, Nina and Mueller, Steffen and Rabe, Sophie and Eichler, Sarah and John, Michael and V{\"o}ller, Heinz and Mayer, Frank},
title = {Reliability and validity of the Kinect V2 for the assessment of lower extremity rehabilitation exercises},
series = {Gait \& posture},
volume = {70},
journal = {Gait \& posture},
publisher = {Elsevier},
address = {Clare},
issn = {0966-6362},
doi = {10.1016/j.gaitpost.2019.03.020},
pages = {330 -- 335},
year = {2019},
abstract = {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.},
language = {en}
}
@article{WochatzRabeWolteretal.2017,
author = {Wochatz, Monique and Rabe, Sophie and Wolter, Martin and Engel, Tilman and Mueller, Steffen and Mayer, Frank},
title = {Reproducibility of scapular muscle activity in isokinetic shoulder flexion and extension},
series = {Journal of electromyography and kinesiology},
volume = {34},
journal = {Journal of electromyography and kinesiology},
publisher = {Elsevier},
address = {Oxford},
issn = {1050-6411},
doi = {10.1016/j.jelekin.2017.04.006},
pages = {86 -- 92},
year = {2017},
abstract = {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.},
language = {en}
}
@article{WochatzRabeWolteretal.2017,
author = {Wochatz, Monique and Rabe, Sophie and Wolter, Martin and Engel, Tilman and Mueller, Steffen and Mayer, Frank},
title = {Muscle activity of upper and lower trapezius and serratus anterior during unloaded and maximal loaded shoulder flexion and extension},
series = {International Biomechanics},
volume = {4},
journal = {International Biomechanics},
number = {2},
publisher = {Elsevier},
address = {Amsterdam},
doi = {https://doi.org/10.1080/23335432.2017.1364668},
pages = {68 -- 76},
year = {2017},
abstract = {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.},
language = {en}
}
@article{WochatzRabeEngeletal.2021,
author = {Wochatz, Monique and Rabe, Sophie and Engel, Tilman and M{\"u}ller, Steffen and Mayer, Frank},
title = {Scapular kinematics during unloaded and maximal loaded isokinetic concentric and eccentric shoulder flexion and extension movements},
series = {Journal of electromyography \& kinesiology : official journal of the International Society of Electrophysiology and Kinesiology},
volume = {57},
journal = {Journal of electromyography \& kinesiology : official journal of the International Society of Electrophysiology and Kinesiology},
publisher = {Elsevier},
address = {Amsterdam},
issn = {1050-6411},
doi = {10.1016/j.jelekin.2021.102517},
pages = {8},
year = {2021},
abstract = {Characterization of scapular kinematics under demanding load conditions might aid to distinguish between physiological and clinically relevant alterations. Previous investigations focused only on submaximal external load situations. How scapular movement changes with maximal load remains unclear. Therefore, the present study aimed to evaluate 3D scapular kinematics during unloaded and maximal loaded shoulder flexion and extension. Twelve asymptomatic individuals performed shoulder flexion and extension movements under unloaded and maximal concentric and eccentric loaded isokinetic conditions. 3D scapular kinematics assessed with a motion capture system was analyzed for 20° intervals of humeral positions from 20° to 120° flexion. Repeated measures ANOVAs were used to evaluate kinematic differences between load conditions for scapular position angles, scapulohumeral rhythm and scapular motion extent. Increased scapular upward rotation was seen during shoulder flexion and extension as well as decreased posterior tilt and external rotation during eccentric and concentric arm descents of maximal loaded compared to unloaded conditions. Load effects were further seen for the scapulohumeral rhythm with greater scapular involvement at lower humeral positions and increased scapular motion extent under maximal loaded shoulder movements. With maximal load applied to the arm physiological scapular movement pattern are induced that may imply both impingement sparing and causing mechanisms.},
language = {en}
}
@article{WochatzEngelMuelleretal.2020,
author = {Wochatz, Monique and Engel, Tilman and M{\"u}ller, Steffen and Mayer, Frank},
title = {Alterations in scapular kinematics and scapular muscle activity after fatiguing shoulder flexion and extension movements},
series = {Medicine and science in sports and exercise : MSSE},
volume = {52},
journal = {Medicine and science in sports and exercise : MSSE},
number = {17},
publisher = {Lippincott Williams \& Wilkins},
address = {Philadelphia},
issn = {0195-9131},
doi = {10.1249/01.mss.0000676540.02017.2c},
pages = {274 -- 274},
year = {2020},
abstract = {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.},
language = {en}
}
@article{WippertPuschmannArampatzisetal.2017,
author = {Wippert, Pia-Maria and Puschmann, Anne-Katrin and Arampatzis, Adamantios and Schiltenwolf, Marcus and Mayer, Frank},
title = {Diagnosis of psychosocial risk factors in prevention of low back pain in athletes (MiSpEx)},
series = {BMJ Open Sport \& Exercise Medicine},
volume = {3},
journal = {BMJ Open Sport \& Exercise Medicine},
number = {1},
issn = {2055-7647},
doi = {10.1136/bmjsem-2017-000295},
year = {2017},
abstract = {Background Low back pain (LBP) is a common pain syndrome in athletes, responsible for 28\% of missed training days/year. Psychosocial factors contribute to chronic pain development. This study aims to investigate the transferability of psychosocial screening tools developed in the general population to athletes and to define athlete-specific thresholds. Methods Data from a prospective multicentre study on LBP were collected at baseline and 1-year follow-up (n=52 athletes, n=289 recreational athletes and n=246 non-athletes). Pain was assessed using the Chronic Pain Grade questionnaire. The psychosocial Risk Stratification Index (RSI) was used to obtain prognostic information regarding the risk of chronic LBP (CLBP). Individual psychosocial risk profile was gained with the Risk Prevention Index - Social (RPI-S). Differences between groups were calculated using general linear models and planned contrasts. Discrimination thresholds for athletes were defined with receiver operating characteristics (ROC) curves. Results Athletes and recreational athletes showed significantly lower psychosocial risk profiles and prognostic risk for CLBP than non-athletes. ROC curves suggested discrimination thresholds for athletes were different compared with non-athletes. Both screenings demonstrated very good sensitivity (RSI=100\%; RPI-S: 75\%-100\%) and specificity (RSI: 76\%-93\%; RPI-S: 71\%-93\%). RSI revealed two risk classes for pain intensity (area under the curve (AUC) 0.92(95\% CI 0.85 to 1.0)) and pain disability (AUC 0.88(95\% CI 0.71 to 1.0)). Conclusions Both screening tools can be used for athletes. Athlete-specific thresholds will improve physicians' decision making and allow stratified treatment and prevention.},
language = {en}
}
@article{WippertDeWittHubertsKlipkeretal.2015,
author = {Wippert, Pia-Maria and De Witt Huberts, Jessie and Klipker, Kathrin and Gantz, Simone and Schiltenwolf, Marcus and Mayer, Frank},
title = {Development and content of the behavioral therapy module of the MiSpEx intervention. Randomized, controlled trial on chronic nonspecific low back pain},
series = {Der Schmerz : Organ der Deutschen Gesellschaft zum Studium des Schmerzes, der {\"O}sterreichischen Schmerzgesellschaft und der Deutschen Interdisziplin{\"a}ren Vereinigung f{\"u}r Schmerztherapie},
volume = {29},
journal = {Der Schmerz : Organ der Deutschen Gesellschaft zum Studium des Schmerzes, der {\"O}sterreichischen Schmerzgesellschaft und der Deutschen Interdisziplin{\"a}ren Vereinigung f{\"u}r Schmerztherapie},
number = {6},
publisher = {Springer},
address = {New York},
issn = {0932-433X},
doi = {10.1007/s00482-015-0044-y},
pages = {658 -- 663},
year = {2015},
abstract = {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.},
language = {de}
}
@article{WippertArampatzisBanzeretal.2019,
author = {Wippert, Pia-Maria and Arampatzis, Adamantios and Banzer, Winfried and Beck, Heidrun and Hasenbring, Monika Ilona and Schiltenwolf, Marcus and Schneider, Christian and Stengel, Dirk and Platen, Petra and Mayer, Frank},
title = {Psychosoziale Risikofaktoren in der Entstehung von chronisch unspezifischen R{\"u}ckenschmerzen},
series = {Zeitschrift f{\"u}r Sportpsychologie},
volume = {26},
journal = {Zeitschrift f{\"u}r Sportpsychologie},
number = {1},
publisher = {Hogrefe},
address = {G{\"o}ttingen},
issn = {1612-5010},
doi = {10.1026/1612-5010/a000245},
pages = {25 -- 35},
year = {2019},
abstract = {Chronisch unspezifische R{\"u}ckenschmerzen (CURS) geh{\"o}ren international zu den h{\"a}ufigsten Schmerzph{\"a}nomenen und k{\"o}nnen f{\"u}r Athletinnen und Athleten karrierelimitierend sein. Knapp ein Drittel der j{\"a}hrlichen Trainingsausfallzeiten werden auf CURS zur{\"u}ckgef{\"u}hrt. In der Entstehung von chronischen Schmerzen ist ein multifaktorielles {\"A}tiologiemodell mit einem signifikanten Einfluss psychosozialer Risikofaktoren evident. Obwohl dies in der Allgemeinbev{\"o}lkerung bereits gut erforscht ist, gibt es in der Sportwissenschaft vergleichsweise wenige Arbeiten dar{\"u}ber. Dieses Thema wird daher in drei Multicenterstudien und zahlreichen Teilstudien des MiSpEx-Netzwerks (Medicine in Spine-Exercise-Network, F{\"o}rderzeitraum 2011 - 2018) aufgegriffen. Entsprechend der Empfehlung einer fr{\"u}hzeitigen Diagnostik von Chronifizierungsfaktoren in der „Nationalen Versorgungsleitlinie Kreuzschmerz", besch{\"a}ftigt sich das Netzwerk u. a. mit der {\"U}berpr{\"u}fung, Entwicklung und Evaluation diagnostischer M{\"o}glichkeiten. Der vorliegende Beitrag beschreibt die Entwicklung einer Diagnostik von psychosozialen Risikofaktoren, die einerseits eine Einsch{\"a}tzung des Risikos der Entwicklung von CURS und andererseits eine individuelle Zuweisung zu (Trainings)Interventionen erlaubt. Es wird die Entwicklungsrationale beschrieben und dabei verschiedene methodische Herangehensweisen und Entscheidungssequenzen reflektiert.},
language = {de}
}
@article{VerchHirschmuellerMuelleretal.2018,
author = {Verch, Ronald and Hirschm{\"u}ller, Anja and M{\"u}ller, Juliane and Baur, Heiner and Mayer, Frank and M{\"u}ller, Steffen},
title = {Is in-toing gait physiological in children?},
series = {Gait \& posture},
volume = {66},
journal = {Gait \& posture},
publisher = {Elsevier},
address = {Clare},
issn = {0966-6362},
doi = {10.1016/j.gaitpost.2018.08.019},
pages = {70 -- 75},
year = {2018},
abstract = {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.},
language = {en}
}
@article{SchraplauBlockHaeusleretal.2021,
author = {Schraplau, Anne and Block, Andrea and H{\"a}usler, Andreas and Wippert, Pia-Maria and Rapp, Michael A. and V{\"o}ller, Heinz and Bonaventura, Klaus and Mayer, Frank},
title = {Mobile diagnostics and consultation for the prevention of the metabolic syndrome and its secondary diseases in Brandenburg—study protocol of a regional prospective cohort study},
series = {Pilot and Feasibility Studies},
volume = {7},
journal = {Pilot and Feasibility Studies},
publisher = {BioMed Central (Springer Nature)},
address = {London},
issn = {2055-5784},
doi = {10.1186/s40814-021-00898-w},
pages = {1 -- 11},
year = {2021},
abstract = {Background The metabolic syndrome (MetS) is a risk cluster for a number of secondary diseases. The implementation of prevention programs requires early detection of individuals at risk. However, access to health care providers is limited in structurally weak regions. Brandenburg, a rural federal state in Germany, has an especially high MetS prevalence and disease burden. This study aims to validate and test the feasibility of a setup for mobile diagnostics of MetS and its secondary diseases, to evaluate the MetS prevalence and its association with moderating factors in Brandenburg and to identify new ways of early prevention, while establishing a "Mobile Brandenburg Cohort" to reveal new causes and risk factors for MetS. Methods In a pilot study, setups for mobile diagnostics of MetS and secondary diseases will be developed and validated. A van will be equipped as an examination room using point-of-care blood analyzers and by mobilizing standard methods. In study part A, these mobile diagnostic units will be placed at different locations in Brandenburg to locally recruit 5000 participants aged 40-70 years. They will be examined for MetS and advice on nutrition and physical activity will be provided. Questionnaires will be used to evaluate sociodemographics, stress perception, and physical activity. In study part B, participants with MetS, but without known secondary diseases, will receive a detailed mobile medical examination, including MetS diagnostics, medical history, clinical examinations, and instrumental diagnostics for internal, cardiovascular, musculoskeletal, and cognitive disorders. Participants will receive advice on nutrition and an exercise program will be demonstrated on site. People unable to participate in these mobile examinations will be interviewed by telephone. If necessary, participants will be referred to general practitioners for further diagnosis. Discussion The mobile diagnostics approach enables early detection of individuals at risk, and their targeted referral to local health care providers. Evaluation of the MetS prevalence, its relation to risk-increasing factors, and the "Mobile Brandenburg Cohort" create a unique database for further longitudinal studies on the implementation of home-based prevention programs to reduce mortality, especially in rural regions. Trial registration German Clinical Trials Register, DRKS00022764; registered 07 October 2020—retrospectively registered.},
language = {en}
}
@article{SchomoellerWeisvonBarbyetal.2019,
author = {Schom{\"o}ller, Anne and Weis, Katharina and von Barby, Reena and H{\"u}bler, Axel and Mayer, Frank and Erler, Thomas},
title = {Restless legs syndrome in childhood and adolescence},
series = {Somnologie : Schlafforschung und Schlafmedizin ; Organ der Deutschen Gesellschaft f{\"u}r Schlafforschung und Schlafmedizin (DGSM)},
volume = {23},
journal = {Somnologie : Schlafforschung und Schlafmedizin ; Organ der Deutschen Gesellschaft f{\"u}r Schlafforschung und Schlafmedizin (DGSM)},
number = {2},
publisher = {Springer},
address = {Cham},
issn = {1432-9123},
doi = {10.1007/s11818-018-0188-y},
pages = {104 -- 108},
year = {2019},
language = {en}
}
@article{SchomoellerSchugardtKotschetal.2021,
author = {Schom{\"o}ller, Anne and Schugardt, Monique and Kotsch, Peggy and Mayer, Frank},
title = {The effect of body composition on cycling power during an incremental test in young athletes},
series = {Journal of strength and conditioning research : the research journal of the NSCA / National Strength \& Conditioning Association},
volume = {35},
journal = {Journal of strength and conditioning research : the research journal of the NSCA / National Strength \& Conditioning Association},
number = {11},
publisher = {Lippincott Williams \& Wilkins},
address = {Philadelphia},
issn = {1064-8011},
doi = {10.1519/JSC.0000000000003271},
pages = {3225 -- 3231},
year = {2021},
abstract = {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.},
language = {en}
}
@article{SchomoellerRischKaplicketal.2021,
author = {Schom{\"o}ller, Anne and Risch, Lucie and Kaplick, Hannes and Wochatz, Monique and Engel, Tilman and Schraplau, Anne and Sonnenburg, Dominik and Huppertz, Alexander and Mayer, Frank},
title = {Inter-rater and inter-session reliability of lumbar paraspinal muscle composition in a mobile MRI device},
series = {BJR : an international journal of radiology, radiation oncology and all related sciences / British Institute of Radiology},
volume = {94},
journal = {BJR : an international journal of radiology, radiation oncology and all related sciences / British Institute of Radiology},
number = {1127},
publisher = {Wiley},
address = {Bognor Regis},
issn = {0007-1285},
doi = {10.1259/bjr.20210141},
pages = {6},
year = {2021},
abstract = {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.
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.
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).
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.},
language = {en}
}
@article{ScharhagRosenbergerWochatzOttoetal.2014,
author = {Scharhag-Rosenberger, Friederike and Wochatz, Monique and Otto, Christoph and Cassel, Michael and Mayer, Frank and Scharhag, J{\"u}rgen},
title = {Blood lactate concentrations are mildly affected by mobile gas exchange measurements},
series = {International journal of sports medicine},
volume = {35},
journal = {International journal of sports medicine},
number = {7},
publisher = {Thieme},
address = {Stuttgart},
issn = {0172-4622},
doi = {10.1055/s-0033-1354386},
pages = {590 -- 594},
year = {2014},
abstract = {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.},
language = {en}
}
@article{ScharhagRosenbergerCarlsohnLundbyetal.2014,
author = {Scharhag-Rosenberger, Friederike and Carlsohn, Anja and Lundby, Carsten and Schueler, Stefan and Mayer, Frank and Scharhag, J{\"u}rgen},
title = {Can more than one incremental cycling test be performed within one day?},
series = {European journal of sport science : official journal of the European College of Sport Science},
volume = {14},
journal = {European journal of sport science : official journal of the European College of Sport Science},
number = {5},
publisher = {Routledge, Taylor \& Francis Group},
address = {Abingdon},
issn = {1746-1391},
doi = {10.1080/17461391.2013.853208},
pages = {459 -- 467},
year = {2014},
abstract = {Changes in performance parameters over four consecutive maximal incremental cycling tests were investigated to determine how many tests can be performed within one single day without negatively affecting performance. Sixteen male and female subjects (eight trained (T): 25 +/- 3 yr, BMI 22.6 +/- 2.5 kg center dot m(-2), maximal power output (P-max) 4.6 +/- 0.5 W center dot kg(-1); eight untrained (UT): 27 +/- 3 yr, BMI 22.3 +/- 1.2 kg center dot m(-2), P-max 2.9 +/- 0.3 W center dot kg(-1)) performed four successive maximal incremental cycling tests separated by 1.5 h of passive rest. Individual energy requirements were covered by standardised meals between trials. Maximal oxygen uptake (VO2max) remained unchanged over the four tests in both groups (P = 0.20 and P = 0.33, respectively). P-max did not change in the T group (P = 0.32), but decreased from the third test in the UT group (P < 0.01). Heart rate responses to submaximal exercise were elevated from the third test in the T group and from the second test in the UT group (P < 0.05). The increase in blood lactate shifted rightward over the four tests in both groups (P < 0.001 and P < 0.01, respectively). Exercise-induced net increases in epinephrine and norepinephrine were not different between the tests in either group (P 0.15). If VO2max is the main parameter of interest, trained and untrained individuals can perform at least four maximal incremental cycling tests per day. However, because other parameters changed after the first and second test, respectively, no more than one test per day should be performed if parameters other than VO2max are the prime focus.},
language = {en}
}
@article{ScharhagRosenbergerCarlsohnCasseletal.2011,
author = {Scharhag-Rosenberger, Friederike and Carlsohn, Anja and Cassel, Michael and Mayer, Frank and Scharhag, J{\"u}rgen},
title = {How to test maximal oxygen uptake a study on timing and testing procedure of a supramaximal verification test},
series = {Applied physiology, nutrition, and metabolism = Physiologie appliqu{\´e}e, nutrition et m{\´e}tabolisme},
volume = {36},
journal = {Applied physiology, nutrition, and metabolism = Physiologie appliqu{\´e}e, nutrition et m{\´e}tabolisme},
number = {1},
publisher = {NRC Research Press},
address = {Ottawa},
issn = {1715-5312},
doi = {10.1139/H10-099},
pages = {153 -- 160},
year = {2011},
abstract = {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.},
language = {en}
}
@article{RischStollSchomoelleretal.2020,
author = {Risch, Lucie and Stoll, Josefine and Schom{\"o}ller, Anne and Engel, Tilman and Mayer, Frank and Cassel, Michael},
title = {Intraindividual Doppler Flow Response to Exercise Differs Between Symptomatic and Asymptomatic Achilles Tendons},
series = {Frontiers in physiology},
volume = {12},
journal = {Frontiers in physiology},
publisher = {Frontiers Research Foundation},
address = {Lausanne, Schweiz},
issn = {1664-042X},
doi = {10.3389/fphys.2021.617497},
pages = {1 -- 8},
year = {2020},
abstract = {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."},
language = {en}
}
@article{RischCasselMayer2017,
author = {Risch, Lucie and Cassel, Michael and Mayer, Frank},
title = {Acute effect of running exercise on physiological Achilles tendon blood flow},
series = {Scandinavian journal of medicine \& science in sports},
volume = {28},
journal = {Scandinavian journal of medicine \& science in sports},
number = {1},
publisher = {Wiley},
address = {Hoboken},
issn = {0905-7188},
doi = {10.1111/sms.12874},
pages = {138 -- 143},
year = {2017},
abstract = {Sonographically detectable intratendinous blood flow (IBF) is found in 50\%-88\% of Achilles tendinopathy patients as well as in up to 35\% of asymptomatic Achilles tendons (AT). Although IBF is frequently associated with tendon pathology, it may also represent a physiological regulation, for example, due to increased blood flow in response to exercise. Therefore, this study aimed to investigate the acute effects of a standardized running exercise protocol on IBF assessed with Doppler ultrasound (DU) Advanced dynamic flow in healthy ATs. 10 recreationally active adults (5 f, 5m; 29 +/- 3years, 1.72 +/- 0.12m, 68 +/- 16kg, physical activity 206 +/- 145minute/wk) with no history of AT pain and inconspicious tendon structure performed 3 treadmill running tasks on separate days (M1-3) with DU examinations directly before and 5, 30, 60, and 120minutes after exercise. At M1, an incremental exercise test was used to determine the individual anaerobic threshold (IAT). At M2 and M3, participants performed 30-minute submaximal constant load tests (CL1/CL2) with an intensity 5\% below IAT. IBF in each tendon was quantified by counting the number of vessels. IBF increased in five ATs from no vessels at baseline to one to four vessels solely detectable 5minutes after CL1 or CL2. One AT had persisting IBF (three vessels) throughout all examinations. Fourteen ATs revealed no IBF at all. Prolonged running led to a physiological, temporary appearance of IBF in 25\% of asymptomatic ATs. To avoid exercise-induced IBF in clinical practice, DU examinations should be performed after 30minutes of rest.},
language = {en}
}
@article{RectorIntziegianniMuelleretal.2017,
author = {Rector, Michael V. and Intziegianni, Konstantina and M{\"u}ller, Steffen and Mayer, Frank and Cassel, Michael},
title = {Reproducibility of an ankle joint rotation correction method for assessment of Achilles tendon elongation},
series = {Isokinetics and exercise science : official journal of the European Isokinetic Society},
volume = {25},
journal = {Isokinetics and exercise science : official journal of the European Isokinetic Society},
number = {1},
publisher = {IOS Press},
address = {Amsterdam},
issn = {0959-3020},
doi = {10.3233/IES-160644},
pages = {47 -- 52},
year = {2017},
abstract = {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.},
language = {en}
}
@article{QuarmbyKhajooeiEngeletal.2019,
author = {Quarmby, Andrew James and Khajooei, Mina and Engel, Tilman and Kaplick, Hannes and Mayer, Frank},
title = {The feasibility of a split-belt instrumented treadmill running protocol with perturbations},
series = {Journal of biomechanics},
volume = {98},
journal = {Journal of biomechanics},
publisher = {Elsevier},
address = {Oxford},
issn = {0021-9290},
doi = {10.1016/j.jbiomech.2019.109493},
pages = {5},
year = {2019},
abstract = {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.
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).
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.},
language = {en}
}