@inproceedings{WochatzKopinskiEngeletal.2014,
  author    = {Wochatz, Monique and Kopinski, Stephan and Engel, Tilman and M{\"u}ller, Steffen and Mayer, Frank},
  title     = {Flexion-extension ratio of trunk peak torque measures and antagonistic activity in males and females},
  series = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine},
  volume    = {46},
  booktitle = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine},
  number    = {5},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {0195-9131},
  pages     = {148 -- 148},
  year      = {2014},
  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{BaurMuellerHirschmuelleretal.2011,
  author    = {Baur, Heiner and M{\"u}ller, Steffen and Hirschm{\"u}ller, Anja and Cassel, Michael and Weber, Josefine and Mayer, Frank},
  title     = {Comparison in lower leg neuromuscular activity between runners with unilateral mid-portion Achilles tendinopathy and healthy individuals},
  series = {Journal of electromyography and kinesiology},
  volume    = {21},
  journal   = {Journal of electromyography and kinesiology},
  number    = {3},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {1050-6411},
  doi       = {10.1016/j.jelekin.2010.11.010},
  pages     = {499 -- 505},
  year      = {2011},
  abstract  = {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.},
  language  = {en}
}
@article{KoenigReschkeWolteretal.2013,
  author    = {K{\"o}nig, Niklas and Reschke, Antje and Wolter, Martin and M{\"u}ller, Steffen and Mayer, Frank and Baur, Heiner},
  title     = {Plantar pressure trigger for reliable nerve stimulus application during dynamic H-reflex measurements},
  series = {Gait \& posture},
  volume    = {37},
  journal   = {Gait \& posture},
  number    = {4},
  publisher = {Elsevier},
  address   = {Clare},
  issn      = {0966-6362},
  doi       = {10.1016/j.gaitpost.2012.09.021},
  pages     = {637 -- 639},
  year      = {2013},
  abstract  = {In dynamic H-reflex measurements, the standardisation of the nerve stimulation to the gait cycle is crucial to avoid misinterpretation due to altered pre-synaptic inhibition. In this pilot study, a plantar pressure sole was used to trigger the stimulation of the tibialis nerve with respect to the gait cycle. Consequently, the intersession reliability of the soleus muscle H-reflex during treadmill walking was investigated. Seven young participants performed walking trials on a treadmill at 5 km/h. The stimulating electrode was placed on the tibial nerve in the popliteal fossa. An EMG was recorded from the soleus muscle. To synchronize the stimulus to the gait cycle, initial heel strike was detected with a plantar pressure sole. Maximum H-reflex amplitude and M-wave amplitude were obtained and the Hmax/Mmax ratio was calculated. Data reveals excellent reliability, ICC = 0.89. Test-retest variability was 13.0\% (+/- 11.8). The Bland-Altman analysis showed a systematic error of 2.4\%. The plantar pressure sole was capable of triggering the stimulation of the tibialis nerve in a reliable way and offers a simple technique for the evaluation of reflex activity during walking.},
  language  = {en}
}
@article{IntziegianniCasselKoenigetal.2015,
  author    = {Intziegianni, Konstantina and Cassel, Michael and K{\"o}nig, Niklas and M{\"u}ller, Steffen and Fr{\"o}hlich, Katja and Mayer, Frank},
  title     = {Ultrasonography for the assessment of the structural properties of the Achilles tendon in asymptomatic individuals: An intra-rater reproducibility study},
  series = {Isokinetics and exercise science : official journal of the European Isokinetic Society},
  volume    = {23},
  journal   = {Isokinetics and exercise science : official journal of the European Isokinetic Society},
  number    = {4},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {0959-3020},
  doi       = {10.3233/IES-150586},
  pages     = {263 -- 270},
  year      = {2015},
  abstract  = {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.},
  language  = {en}
}
@article{EichlerRabeSalzwedeletal.2017,
  author    = {Eichler, Sarah and Rabe, Sophie and Salzwedel, Annett and M{\"u}ller, Steffen and Stoll, Josefine and Tilgner, Nina and John, Michael and Wegschneider, Karl and Mayer, Frank and V{\"o}ller, Heinz},
  title     = {Effectiveness of an interactive telerehabilitation system with home-based exercise training in patients after total hip or knee replacement},
  series = {Trials},
  volume    = {18},
  journal   = {Trials},
  publisher = {BioMed Central},
  address   = {London},
  issn      = {1745-6215},
  doi       = {10.1186/s13063-017-2173-3},
  pages     = {1 -- 7},
  year      = {2017},
  abstract  = {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.},
  language  = {en}
}
@article{AppiahDwomohMuellerMayer2018,
  author    = {Appiah-Dwomoh, Edem Korkor and M{\"u}ller, Steffen and Mayer, Frank},
  title     = {Reproducibility of Static and Dynamic Postural Control Measurement in Adolescent Athletes with Back Pain},
  series = {Rehabilitation Research and Practice},
  volume    = {2018},
  journal   = {Rehabilitation Research and Practice},
  publisher = {Hindawi},
  address   = {New York},
  issn      = {2090-2875},
  doi       = {10.1155/2018/8438350},
  pages     = {1 -- 8},
  year      = {2018},
  abstract  = {Static (one-legged stance) and dynamic (star excursion balance) postural control tests were performed by 14 adolescent athletes with and 17 without back pain to determine reproducibility. The total displacement, mediolateral and anterior-posterior displacements of the centre of pressure in mm for the static, and the normalized and composite reach distances for the dynamic tests were analysed. Intraclass correlation coefficients, 95\% confidence intervals, and a Bland-Altman analysis were calculated for reproducibility. Intraclass correlation coefficients for subjects with (0.54 to 0.65), (0.61 to 0.69) and without (0.45 to 0.49), (0.52 to 0.60) back pain were obtained on the static test for right and left legs, respectively. Likewise, (0.79 to 0.88), (0.75 to 0.93) for subjects with and (0.61 to 0.82), (0.60 to 0.85) for those without back pain were obtained on the dynamic test for the right and left legs, respectively. Systematic bias was not observed between test and retest of subjects on both static and dynamic tests. The one-legged stance and star excursion balance tests have fair to excellent reliabilities on measures of postural control in adolescent athletes with and without back pain. They can be used as measures of postural control in adolescent athletes with and without back pain.},
  language  = {en}
}
@article{HirschmuellerKonstantinidisBauretal.2011,
  author    = {Hirschm{\"u}ller, Anja and Konstantinidis, Lukas and Baur, Heiner and M{\"u}ller, Steffen and Mehlhorn, Alexander and Kontermann, Julia and Grosse, Ulrich and S{\"u}dkamp, Norbert P. and Helwig, Peter},
  title     = {Do changes in dynamic plantar pressure distribution, strength capacity and postural control after intra-articular calcaneal fracture correlate with clinical and radiological outcome?},
  series = {Injury : international journal of the care of the injured},
  volume    = {42},
  journal   = {Injury : international journal of the care of the injured},
  number    = {10},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0020-1383},
  doi       = {10.1016/j.injury.2010.09.040},
  pages     = {1135 -- 1143},
  year      = {2011},
  abstract  = {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.},
  language  = {en}
}
@article{BaurHirschmuellerMuelleretal.2011,
  author    = {Baur, Heiner and Hirschm{\"u}ller, Anja and M{\"u}ller, Steffen and Mayer, Frank},
  title     = {Neuromuscular activity of the peroneal muscle after foot orthoses therapy in runners},
  series = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine},
  volume    = {43},
  journal   = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine},
  number    = {8},
  publisher = {Lippincott Williams \& Wilkins},
  address   = {Philadelphia},
  issn      = {0195-9131},
  doi       = {10.1249/MSS.0b013e31820c64ae},
  pages     = {1500 -- 1506},
  year      = {2011},
  abstract  = {BAUR, H., A. HIRSCHMULLER, S. MULLER, and F. MAYER. Neuromuscular Activity of the Peroneal Muscle after Foot Orthoses Therapy in Runners. Med. Sci. Sports Exerc., Vol. 43, No. 8, pp. 1500-1506, 2011. Purpose: Foot orthoses are a standard option to treat overuse injury. Biomechanical data providing mechanisms of foot orthoses' effectiveness are sparse. Stability of the ankle joint complex might be a key factor. The purpose was therefore to analyze neuromuscular activity of the musculus peroneus longus in runners with overuse injury symptoms treated with foot orthoses. Methods: A total of 99 male and female runners with overuse injury symptoms randomized in a control group (CO) and an orthoses group (OR) were analyzed on a treadmill at 3.3 m.s(-1) before and after an 8-wk foot orthoses intervention. Muscular activity of the musculus peroneus longus was measured and quantified in the time domain (initial onset of activation (T-ini), time of maximal activity (T-max), total time of activation (T-tot)) and amplitude domain (amplitude in preactivation (A(pre)), weight acceptance (A(wa)), push-off (A(po))). Results: Peroneal activity in the time domain did not differ initially between CO and OR, and no effect was observed after therapy (T-ini: CO = -0.88 +/- 0.09, OR = -0.88 +/- 0.08 / T-max: CO = 0.14 +/- 0.06, OR = 0.15 +/- 0.06 / T-tot: CO = 0.40 +/- 0.09, OR = 0.41 +/- 0.09; P > 0.05). In preactivation (Apre), muscle activity was higher in OR after intervention (CO = 0.97 +/- 0.32, 95\% confidence interval = 0.90-1.05; OR = 1.18 +/- 0.43, 95\% confidence interval = 1.08-1.28; P = 0.003). There was no group or intervention effect during stance (A(wa): CO = 2.33 +/- 0.66, OR = 2.33 +/- 0.74 / A(po): CO = 0.80 +/- 0.41, OR = 0.88 +/- 0.40; P > 0.05). Conclusions: Enhanced muscle activation of the musculus peroneus longus in preactivation suggests an altered preprogrammed activity, which might lead to better ankle stability providing a possible mode of action for foot orthoses therapy.},
  language  = {en}
}
@article{MuellerMayerBauretal.2011,
  author    = {M{\"u}ller, Steffen and Mayer, Patrizia and Baur, Heiner and Mayer, Frank},
  title     = {Higher velocities in isokinetic dynamometry a pilot study of new test mode with active compensation of inertia},
  series = {Isokinetics and exercise science : official journal of the European Isokinetic Society},
  volume    = {19},
  journal   = {Isokinetics and exercise science : official journal of the European Isokinetic Society},
  number    = {2},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {0959-3020},
  doi       = {10.3233/IES-2011-0398},
  pages     = {63 -- 70},
  year      = {2011},
  abstract  = {Isokinetic dynamometry is a standard technique for strength testing and training. Nevertheless reliability and validity is limited due to inertia effects, especially for high velocities. Therefore in a first methodological approach the purpose was to evaluate a new isokinetic measurement mode including inertia compensation compared to a classic isokinetic measurement mode for single and multijoint movements at different velocities. Isokinetic maximum strength measurements were carried out in 26 healthy active subjects. Tests were performed using classic isokinetic and new isokinetic mode in random order. Maximum torque/force, maximum movement velocity and time for acceleration were calculated. For inter-instrument agreement Bland and Altman analysis, systematic and random error was quantified. Differences between both methods were assessed (ANOVA alpha = 0.05). Bland and Altman analysis showed the highest agreement between the two modes for strength and velocity measurements (bias: < +/- 1.1\%; LOA: < 14.2\%) in knee flexion/extension at slow isokinetic velocity (60 degrees/s). Least agreement (range: bias: -67.6\% +/- 119.0\%; LOA: 53.4\% 69.3\%) was observed for shoulder/arm test at high isokinetic velocity (360 degrees/s). The Isokin(new) mode showed higher maximum movement velocities (p < 0.05). For low isokinetic velocities the new mode agrees with the classic mode. Especially at high isokinetic velocities the new isokinetic mode shows relevant benefits coupled with a possible trade-off with the force/torque measurement. In conclusion, this study offers for the first time a comparison between the 'classical' and inertia-compensated isokinetic dynamometers indicating the advantages and disadvantages associated with each individual approach, particularly as they relate to medium or high velocities in testing and training.},
  language  = {en}
}
@article{HirschmuellerBaurMuelleretal.2011,
  author    = {Hirschm{\"u}ller, Anja and Baur, Heiner and M{\"u}ller, Steffen and Helwig, Peter and Dickhuth, Hans-Hermann and Mayer, Frank},
  title     = {Clinical effectiveness of customised sport shoe orthoses for overuse injuries in runners a randomised controlled study},
  series = {British journal of sports medicine : the journal of sport and exercise medicine},
  volume    = {45},
  journal   = {British journal of sports medicine : the journal of sport and exercise medicine},
  number    = {12},
  publisher = {BMJ Publ. Group},
  address   = {London},
  issn      = {0306-3674},
  doi       = {10.1136/bjsm.2008.055830},
  pages     = {959 -- 965},
  year      = {2011},
  abstract  = {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.},
  language  = {en}
}
@article{MuellerStollCasseletal.2017,
  author    = {M{\"u}ller, Steffen and Stoll, Josefine and Cassel, Michael and Mayer, Frank},
  title     = {Trunk Muscle Activity during Drop Jump Performance in Adolescent Athletes with Back Pain},
  series = {Frontiers in physiology},
  volume    = {8},
  journal   = {Frontiers in physiology},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-042X},
  doi       = {10.3389/fphys.2017.00274},
  year      = {2017},
  abstract  = {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.},
  language  = {en}
}
@article{CasselIntziegianniRischetal.2017,
  author    = {Cassel, Michael and Intziegianni, Konstantina and Risch, Lucie and M{\"u}ller, Steffen and Engel, Tilman and Mayer, Frank},
  title     = {Physiological Tendon Thickness Adaptation in Adolescent Elite Athletes},
  series = {Frontiers in physiology},
  volume    = {8},
  journal   = {Frontiers in physiology},
  publisher = {Frontiers},
  address   = {Lausanne},
  issn      = {1664-042X},
  doi       = {10.3389/fphys.2017.00795},
  pages     = {1 -- 8},
  year      = {2017},
  abstract  = {Increased Achilles (AT) and Patellar tendon (PT) thickness in adolescent athletes compared to non-athletes could be shown. However, it is unclear, if changes are of pathological or physiological origin due to training. The aim of this study was to determine physiological AT and PT thickness adaptation in adolescent elite athletes compared to non-athletes, considering sex and sport. In a longitudinal study design with two measurement days (M1/M2) within an interval of 3.2 ± 0.8 years, 131 healthy adolescent elite athletes (m/f: 90/41) out of 13 different sports and 24 recreationally active controls (m/f: 6/18) were included. Both ATs and PTs were measured at standardized reference points. Athletes were divided into 4 sport categories [ball (B), combat (C), endurance (E) and explosive strength sports (S)]. Descriptive analysis (mean ± SD) and statistical testing for group differences was performed (α = 0.05). AT thickness did not differ significantly between measurement days, neither in athletes (5.6 ± 0.7 mm/5.6 ± 0.7 mm) nor in controls (4.8 ± 0.4 mm/4.9 ± 0.5 mm, p > 0.05). For PTs, athletes presented increased thickness at M2 (M1: 3.5 ± 0.5 mm, M2: 3.8 ± 0.5 mm, p < 0.001). In general, males had thicker ATs and PTs than females (p < 0.05). Considering sex and sports, only male athletes from B, C, and S showed significant higher PT-thickness at M2 compared to controls (p ≤ 0.01). Sport-specific adaptation regarding tendon thickness in adolescent elite athletes can be detected in PTs among male athletes participating in certain sports with high repetitive jumping and strength components. Sonographic microstructural analysis might provide an enhanced insight into tendon material properties enabling the differentiation of sex and influence of different sports.},
  language  = {en}
}
@article{AppiahDwomohMuellerMayer2019,
  author    = {Appiah-Dwomoh, Edem Korkor and M{\"u}ller, Steffen and Mayer, Frank},
  title     = {Is there an association between variables of static and dynamic postural control in adolescent athletes with back pain?},
  series = {German Journal of Exercise and Sport Research},
  volume    = {49},
  journal   = {German Journal of Exercise and Sport Research},
  number    = {2},
  publisher = {Springer},
  address   = {New York},
  issn      = {2509-3142},
  doi       = {10.1007/s12662-019-00573-6},
  pages     = {150 -- 155},
  year      = {2019},
  abstract  = {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.},
  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}
}
@misc{BaurHirschmuellerJahnetal.2008,
  author    = {Baur, Heiner and Hirschm{\"u}ller, Anja and Jahn, Michael and M{\"u}ller, Steffen and Mayer, Frank},
  title     = {Therapeutic efficiency and biomechanical effects of sport insoles in female runners},
  series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe},
  number    = {624},
  issn      = {1866-8364},
  doi       = {10.25932/publishup-43552},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435525},
  pages     = {4},
  year      = {2008},
  language  = {en}
}
@article{BaurMuellerHirschmuelleretal.2006,
  author    = {Baur, Heiner and M{\"u}ller, Steffen and Hirschm{\"u}ller, Anja and Huber, Georg and Mayer, Frank},
  title     = {Reactivity, stability, and strength performance capacity in motor sports},
  series = {British journal of sports medicine : the journal of sport and exercise medicine},
  volume    = {40},
  journal   = {British journal of sports medicine : the journal of sport and exercise medicine},
  publisher = {BMJ Publ. Group},
  address   = {London},
  issn      = {0306-3674},
  doi       = {10.1136/bjsm.2006.025783},
  pages     = {906 -- 910},
  year      = {2006},
  abstract  = {Background: Racing drivers require multifaceted cognitive and physical abilities in a multitasking situation. A knowledge of their physical capacities may help to improve fitness and performance. Objective: To compare reaction time, stability performance capacity, and strength performance capacity of elite racing drivers with those of age-matched, physically active controls. Methods: Eight elite racing drivers and 10 physically active controls matched for age and weight were tested in a reaction and determination test requiring upper and lower extremity responses to visual and audio cues. Further tests comprised evaluation of one-leg postural stability on a two-dimensional moveable platform, measures of maximum strength performance capacity of the extensors of the leg on a leg press, and a test of force capacity of the arms in a sitting position at a steering wheel. An additional arm endurance test consisted of isometric work at the steering wheel at + 30 degrees and -30 degrees where an eccentric threshold load of 30 N.m was applied. Subjects had to hold the end positions above this threshold until exhaustion. Univariate one way analysis of variance (alpha = 0.05) including a Bonferroni adjustment was used to detect group differences between the drivers and controls. Results: The reaction time of the racing drivers was significantly faster than the controls ( p = 0.004). The following motor reaction time and reaction times in the multiple determination test did not differ between the groups. No significant differences (p> 0.05) were found for postural stability, leg extensor strength, or arm strength and endurance. Conclusions: Racing drivers have faster reaction times than age-matched physically active controls. Further development of motor sport-specific test protocols is suggested. According to the requirements of motor racing, strength and sensorimotor performance capacity can potentially be improved.},
  language  = {en}
}
@article{MuellerEngelMuelleretal.2018,
  author    = {Mueller, Steffen and Engel, Tilman and M{\"u}ller, Juliane and Stoll, Josefine and Baur, Heiner and Mayer, Frank},
  title     = {Sensorimotor exercises and enhanced trunk function},
  series = {International journal of sports medicine},
  volume    = {39},
  journal   = {International journal of sports medicine},
  number    = {7},
  publisher = {Thieme},
  address   = {Stuttgart},
  issn      = {0172-4622},
  doi       = {10.1055/a-0592-7286},
  pages     = {555 -- 563},
  year      = {2018},
  abstract  = {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).},
  language  = {en}
}
@article{MayerBonaventuraCasseletal.2012,
  author    = {Mayer, Frank and Bonaventura, Klaus and Cassel, Michael and M{\"u}ller, Steffen and Weber, Josefine and Scharhag-Rosenberger, Friederike and Carlsohn, Anja and Baur, Heiner and Scharhag, J{\"u}rgen},
  title     = {Medical results of preparticipation examination in adolescent athletes},
  series = {British journal of sports medicine : the journal of sport and exercise medicine},
  volume    = {46},
  journal   = {British journal of sports medicine : the journal of sport and exercise medicine},
  number    = {7},
  publisher = {BMJ Publ. Group},
  address   = {London},
  issn      = {0306-3674},
  doi       = {10.1136/bjsports-2011-090966},
  pages     = {524 -- 530},
  year      = {2012},
  abstract  = {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.},
  language  = {en}
}
@article{BaurHirschmuellerMuelleretal.2012,
  author    = {Baur, Heiner and Hirschm{\"u}ller, Anja and M{\"u}ller, Steffen and Cassel, Michael and Mayer, Frank},
  title     = {Is EMG of the lower leg dependent on weekly running mileage?},
  series = {International journal of sports medicine},
  volume    = {33},
  journal   = {International journal of sports medicine},
  number    = {1},
  publisher = {Thieme},
  address   = {Stuttgart},
  issn      = {0172-4622},
  doi       = {10.1055/s-0031-1286250},
  pages     = {53 -- 57},
  year      = {2012},
  abstract  = {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.},
  language  = {en}
}