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 - Müller, Juliane A1 - Müller, Steffen A1 - Stoll, Josefine A1 - Fröhlich, K. A1 - Otto, Christoph A1 - Mayer, Frank T1 - Back pain prevalence in adolescent athletes JF - Scandinavian journal of medicine & science in sports N2 - The research aimed to investigate back pain (BP) prevalence in a large cohort of young athletes with respect to age, gender, and sport discipline. BP (within the last 7days) was assessed with a face scale (face 1-2=no pain; face 3-5=pain) in 2116 athletes (m/f 61%/39%; 13.3 +/- 1.7years; 163.0 +/- 11.8cm; 52.6 +/- 13.9kg; 4.9 +/- 2.7 training years; 8.4 +/- 5.7 training h/week). Four different sports categories were devised (a: combat sports, b: game sports; c: explosive strength sport; d: endurance sport). Analysis was described descriptively, regarding age, gender, and sport. In addition, 95% confidence intervals (CI) were calculated. About 168 (8%) athletes were allocated into the BP group. About 9% of females and 7% of males reported BP. Athletes, 11-13years, showed a prevalence of 2-4%; while prevalence increased to 12-20% in 14- to 17-year olds. Considering sport discipline, prevalence ranged from 3% (soccer) to 14% (canoeing). Prevalences in weight lifting, judo, wrestling, rowing, and shooting were 10%; in boxing, soccer, handball, cycling, and horse riding, 6%. 95% CI ranged between 0.08-0.11. BP exists in adolescent athletes, but is uncommon and shows no gender differences. A prevalence increase after age 14 is obvious. Differentiated prevention programs in daily training routines might address sport discipline-specific BP prevalence. KW - Young athletes KW - back pain KW - prevalence KW - types of sports Y1 - 2017 U6 - https://doi.org/10.1111/sms.12664 SN - 0905-7188 SN - 1600-0838 VL - 27 SP - 448 EP - 454 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Hirschmüller, Anja A1 - Baur, Heiner A1 - Müller, Steffen A1 - Helwig, Peter A1 - Dickhuth, Hans-Hermann A1 - Mayer, Frank T1 - Clinical effectiveness of customised sport shoe orthoses for overuse injuries in runners a randomised controlled study JF - British journal of sports medicine : the journal of sport and exercise medicine N2 - Background and objectives Treatment of chronic running-related overuse injuries by orthopaedic shoe orthoses is very common but not evidence-based to date. Hypothesis Polyurethane foam orthoses adapted to a participant's barefoot plantar pressure distribution are an effective treatment option for chronic overuse injuries in runners. Design Prospective, randomised, controlled clinical trial. Intervention 51 patients with running injuries were treated with custom-made, semirigid running shoe orthoses for 8 weeks. 48 served as a randomised control group that continued regular training activity without any treatment. Main outcome measures Evaluation was made by the validated pain questionnaire Subjective Pain Experience Scale, the pain disability index and a comfort index in the orthoses group (ICI). Results There were statistically significant differences between the orthoses and control groups at 8 weeks for the pain disability index (mean difference 3.2; 95% CI 0.9 to 5.5) and the Subjective Pain Experience Scale (6.6; 2.6 to 10.6). The patients with orthoses reported a rising wearing comfort (pre-treatment ICI 69/100; post-treatment ICI 83/100) that was most pronounced in the first 4 weeks (ICI 80.4/100). Conclusion Customised polyurethane running shoe orthoses are an effective conservative therapy strategy for chronic running injuries with high comfort and acceptance of injured runners. Y1 - 2011 U6 - https://doi.org/10.1136/bjsm.2008.055830 SN - 0306-3674 VL - 45 IS - 12 SP - 959 EP - 965 PB - BMJ Publ. Group CY - London 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 - CHAP A1 - Carlsohn, Anja A1 - Weber, Josefine A1 - Müller, Juliane A1 - Stuwe, Anja A1 - Müller, Steffen A1 - Mayer, Frank T1 - Dietary intake to reduce body mass before competition in german judo 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 - 109 EP - 109 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Hirschmüller, Anja A1 - Konstantinidis, Lukas A1 - Baur, Heiner A1 - Müller, Steffen A1 - Mehlhorn, Alexander A1 - Kontermann, Julia A1 - Grosse, Ulrich A1 - Südkamp, Norbert P. A1 - Helwig, Peter T1 - Do changes in dynamic plantar pressure distribution, strength capacity and postural control after intra-articular calcaneal fracture correlate with clinical and radiological outcome? JF - Injury : international journal of the care of the injured N2 - Fractures of the calcaneus are often associated with serious permanent disability, a considerable reduction in quality of life, and high socio-economic cost. Although some studies have already reported changes in plantar pressure distribution after calcaneal fracture, no investigation has yet focused on the patient's strength and postural control. Method: 60 patients with unilateral, operatively treated, intra-articular calcaneal fractures were clinically and biomechanically evaluated >1 year postoperatively (physical examination, SF-36, AOFAS score, lower leg isokinetic strength, postural control and gait analysis including plantar pressure distribution). Results were correlated to clinical outcome and preoperative radiological findings (Bohler angle, Zwipp and Sanders Score). Results: Clinical examination revealed a statistically significant reduction in range of motion at the tibiotalar and the subtalar joint on the affected side. Additionally, there was a statistically significant reduction of plantar flexor peak torque of the injured compared to the uninjured limb (p < 0.001) as well as a reduction in postural control that was also more pronounced on the initially injured side (standing duration 4.2 +/- 2.9 s vs. 7.6 +/- 2.1 s, p < 0.05). Plantar pressure measurements revealed a statistically significant pressure reduction at the hindfoot (p = 0.0007) and a pressure increase at the midfoot (p = 0.0001) and beneath the lateral forefoot (p = 0.037) of the injured foot. There was only a weak correlation between radiological classifications and clinical outcome but a moderate correlation between strength differences and the clinical questionnaires (CC 0.27-0.4) as well as between standing duration and the clinical questionnaires. Although thigh circumference was also reduced on the injured side, there was no important relationship between changes in lower leg circumference and strength suggesting that measurement of leg circumference may not be a valid assessment of maximum strength deficits. Self-selected walking speed was the parameter that showed the best correlation with clinical outcome (AOFAS score). Conclusion: Calcaneal fractures are associated with a significant reduction in ankle joint ROM, plantar flexion strength and postural control. These impairments seem to be highly relevant to the patients. Restoration of muscular strength and proprioception should therefore be aggressively addressed in the rehabilitation process after these fractures. KW - Intra-articular calcaneal fracture KW - Calcaneus KW - Muscle strength KW - Peak torque KW - Plantar pressure distribution KW - Proprioception KW - Postural control KW - Balance KW - Gait KW - Rehabilitation Y1 - 2011 U6 - https://doi.org/10.1016/j.injury.2010.09.040 SN - 0020-1383 VL - 42 IS - 10 SP - 1135 EP - 1143 PB - Elsevier CY - Oxford 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 - Eichler, Sarah A1 - Rabe, Sophie A1 - Salzwedel, Annett A1 - Müller, Steffen A1 - Stoll, Josefine A1 - Tilgner, Nina A1 - John, Michael A1 - Wegschneider, 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 BT - 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 SP - 1 EP - 7 PB - BioMed Central CY - London ER - TY - CHAP A1 - Müller, Juliane A1 - Weber, Josefine A1 - Otto, Christoph A1 - Müller, Steffen A1 - Mayer, Frank T1 - Effects of six-month trunk stability exercises on low back pain prevalence in young 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 - 601 EP - 601 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Müller, Juliane A1 - Engel, Tilman A1 - Müller, Steffen A1 - Stoll, Josefine A1 - Baur, Heiner A1 - Mayer, Frank T1 - Effects of sudden walking perturbations on neuromuscular reflex activity and three-dimensional motion of the trunk in healthy controls and back pain symptomatic subjects JF - PLoS one N2 - Background Back pain patients (BPP) show delayed muscle onset, increased co-contractions, and variability as response to quasi-static sudden trunk loading in comparison to healthy controls (H). However, it is unclear whether these results can validly be transferred to suddenly applied walking perturbations, an automated but more functional and complex movement pattern. There is an evident need to develop research-based strategies for the rehabilitation of back pain. Therefore, the investigation of differences in trunk stability between H and BPP in functional movements is of primary interest in order to define suitable intervention regimes. The purpose of this study was to analyse neuromuscular reflex activity as well as three-dimensional trunk kinematics between H and BPP during walking perturbations. Methods Eighty H (31m/49f;29±9yrs;174±10cm;71±13kg) and 14 BPP (6m/8f;30±8yrs;171±10cm;67±14kg) walked (1m/s) on a split-belt treadmill while 15 right-sided perturbations (belt decelerating, 40m/s2, 50ms duration; 200ms after heel contact) were randomly applied. Trunk muscle activity was assessed using a 12-lead EMG set-up. Trunk kinematics were measured using a 3-segment-model consisting of 12 markers (upper thoracic (UTA), lower thoracic (LTA), lumbar area (LA)). EMG-RMS ([%],0-200ms after perturbation) was calculated and normalized to the RMS of unperturbed gait. Latency (TON;ms) and time to maximum activity (TMAX;ms) were analysed. Total motion amplitude (ROM;[°]) and mean angle (Amean;[°]) for extension-flexion, lateral flexion and rotation were calculated (whole stride cycle; 0-200ms after perturbation) for each of the three segments during unperturbed and perturbed gait. For ROM only, perturbed was normalized to unperturbed step [%] for the whole stride as well as the 200ms after perturbation. Data were analysed descriptively followed by a student´s t-test to account for group differences. Co-contraction was analyzed between ventral and dorsal muscles (V:R) as well as side right:side left ratio (Sright:Sleft). The coefficient of variation (CV;%) was calculated (EMG-RMS;ROM) to evaluate variability between the 15 perturbations for all groups. With respect to unequal distribution of participants to groups, an additional matched-group analysis was conducted. Fourteen healthy controls out of group H were sex-, age- and anthropometrically matched (group Hmatched) to the BPP. Results No group differences were observed for EMG-RMS or CV analysis (EMG/ROM) (p>0.025). Co-contraction analysis revealed no differences for V:R and Srigth:Sleft between the groups (p>0.025). BPP showed an increased TON and TMAX, being significant for Mm. rectus abdominus (p = 0.019) and erector spinae T9/L3 (p = 0.005/p = 0.015). ROM analysis over the unperturbed stride cycle revealed no differences between groups (p>0.025). Normalization of perturbed to unperturbed step lead to significant differences for the lumbar segment (LA) in lateral flexion with BPP showing higher normalized ROM compared to Hmatched (p = 0.02). BPP showed a significant higher flexed posture (UTA (p = 0.02); LTA (p = 0.004)) during normal walking (Amean). Trunk posture (Amean) during perturbation showed higher trunk extension values in LTA segments for H/Hmatched compared to BPP (p = 0.003). Matched group (BPP vs. Hmatched) analysis did not show any systematic changes of all results between groups. Conclusion BPP present impaired muscle response times and trunk posture, especially in the sagittal and transversal planes, compared to H. This could indicate reduced trunk stability and higher loading during gait perturbations. Y1 - 2017 U6 - https://doi.org/10.1371/journal.pone.0174034 SN - 1932-6203 VL - 12 IS - 3 PB - PLoS CY - Lawrence, Kan. ER -