@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{BuschBlasimannMayeretal.2021, author = {Busch, Aglaja and Blasimann, Angela and Mayer, Frank and Baur, Heiner}, title = {Alterations in sensorimotor function after ACL reconstruction during active joint position sense testing. A systematic review}, series = {PLOS ONE}, volume = {16}, journal = {PLOS ONE}, number = {6}, publisher = {PLOS}, address = {San Francisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0253503}, pages = {14}, year = {2021}, abstract = {Background The anterior cruciate ligament (ACL) rupture can lead to impaired knee function. Reconstruction decreases the mechanical instability but might not have an impact on sensorimotor alterations. Objective Evaluation of the sensorimotor function measured with the active joint position sense (JPS) test in anterior cruciate ligament (ACL) reconstructed patients compared to the contralateral side and a healthy control group. Methods The databases MEDLINE, CINAHL, EMBASE, PEDro, Cochrane Library and SPORTDiscus were systematically searched from origin until April 2020. Studies published in English, German, French, Spanish or Italian language were included. Evaluation of the sensorimotor performance was restricted to the active joint position sense test in ACL reconstructed participants or healthy controls. The Preferred Items for Systematic Reviews and Meta-Analyses guidelines were followed. Study quality was evaluated using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Data was descriptively synthesized. Results Ten studies were included after application of the selective criteria. Higher angular deviation, reaching significant difference (p < 0.001) in one study, was shown up to three months after surgery in the affected limb. Six months post-operative significantly less error (p < 0.01) was found in the reconstructed leg compared to the contralateral side and healthy controls. One or more years after ACL reconstruction significant differences were inconsistent along the studies. Conclusions Altered sensorimotor function was present after ACL reconstruction. Due to inconsistencies and small magnitudes, clinical relevance might be questionable. JPS testing can be performed in acute injured persons and prospective studies could enhance knowledge of sensorimotor function throughout the rehabilitative processes.}, language = {en} } @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{BuschBlasimannHenleetal.2019, author = {Busch, Aglaja and Blasimann, Angela and Henle, Philipp and Baur, Heiner}, title = {Neuromuscular activity during stair descent in ACL reconstructed patients}, series = {The Knee}, volume = {26}, journal = {The Knee}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0968-0160}, doi = {10.1016/j.knee.2018.12.011}, pages = {310 -- 316}, year = {2019}, abstract = {Background: The anterior cruciate ligament (ACL) rupture is a severe knee injury. Altered kinematics and kinetics in ACL reconstructed (ACL-R) patients compared to healthy participants (ACL-I) are known and attributed to an altered sensorimotor control. However, studies on neuromuscular control often lack homogeneous patient cohorts. The objective was to examine neuromuscular activity during stair descent in patients one year after ACL reconstruction. Method: Neuromuscular activity of vastus medialis (VM) and lateralis (VL), biceps femoris (BF) and semitendinosus (ST) was recorded by electromyography in 10 ACL-R (age: 26 +/- 10 years; height: 175 +/- 6 cm; mass: 75 +/- 14 kg) and 10 healthy matched controls (age: 31 +/- 7 years; height: 175 +/- 7 cm; mass: 68 +/- 10 kg). A 10-minute walking treadmill warm-up was used for submaximal normalization. Afterwards participants descended 10 times a six-step stairway at a self-selected speed. The movement was separated into pre-activation (PRE), weight acceptance (WA) and push-off phase (PO). Normalized root mean squares for each muscle, limb and movement phase were calculated. Kruskal-Wallis ANOVA compared ACL-R injured and contralateral leg and the ACL-I leg (alpha = 0.05). Results: Significant increased normalised activity in ST during WA in ACL-R injured leg compared to ACL-I and during PO in VL in the ACL-R contralateral leg compared to ACL-I. Decreased activity was shown in VM in ACL-R injured compared to contralateral leg (p < 0.05). Conclusion: Altered neuromuscular activations are present one year after ACL reconstruction compared to the contralateral and healthy matched control limb. Current standard rehabilitation programs may not be able to fully restore sensorimotor control and demand further investigations. (C) 2018 Elsevier B.V. All rights reserved.}, 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{MuellerCarlsohnMuelleretal.2016, author = {Mueller, Steffen and Carlsohn, Anja and Mueller, Juliane and Baur, Heiner and Mayer, Frank}, title = {Influence of Obesity on Foot Loading Characteristics in Gait for Children Aged 1 to 12 Years}, series = {PLoS one}, volume = {11}, journal = {PLoS one}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0149924}, pages = {1710 -- 1717}, year = {2016}, abstract = {Background Overweight and obesity are increasing health problems that are not restricted to adults only. Childhood obesity is associated with metabolic, psychological and musculoskeletal comorbidities. However, knowledge about the effect of obesity on the foot function across maturation is lacking. Decreased foot function with disproportional loading characteristics is expected for obese children. The aim of this study was to examine foot loading characteristics during gait of normal-weight, overweight and obese children aged 1-12 years. Methods Results Mean walking velocity was 0.95 +/- 0.25 m/s with no differences between normal-weight, overweight or obese children (p = 0.0841). Results show higher foot contact area, arch index, peak pressure and force time integral in overweight and obese children (p< 0.001). Obese children showed the 1.48-fold (1 year-old) to 3.49-fold (10 year-old) midfoot loading (FTI) compared to normal-weight. Conclusion Additional body mass leads to higher overall load, with disproportional impact on the midfoot area and longitudinal foot arch showing characteristic foot loading patterns. Already the feet of one and two year old children are significantly affected. Childhood overweight and obesity is not compensated by the musculoskeletal system. To avoid excessive foot loading with potential risk of discomfort or pain in childhood, prevention strategies should be developed and validated for children with a high body mass index and functional changes in the midfoot area. The presented plantar pressure values could additionally serve as reference data to identify suspicious foot loading patterns in children.}, language = {en} } @article{MuellerMuellerEngeletal.2016, author = {M{\"u}ller, Juliane and M{\"u}ller, Steffen and Engel, Tilman and Reschke, Antje and Baur, Heiner and Mayer, Frank}, title = {Stumbling reactions during perturbed walking: Neuromuscular reflex activity and 3-D kinematics of the trunk - A pilot study}, series = {Journal of biomechanics}, volume = {49}, journal = {Journal of biomechanics}, publisher = {Elsevier}, address = {Oxford}, issn = {0021-9290}, doi = {10.1016/j.jbiomech.2015.09.041}, pages = {933 -- 938}, year = {2016}, abstract = {Stumbling led to an increase in ROM, compared to unperturbed gait, in all segments and planes. These increases ranged between 107 +/- 26\% (UTA/rotation) and 262 +/- 132\% (UTS/lateral flexion), significant only in lateral flexion. EMG activity of the trunk was increased during stumbling (abdominal: 665 +/- 283\%; back: 501 +/- 215\%), without significant differences between muscles. Provoked stumbling leads to a measurable effect on the trunk, quantifiable by an increase in ROM and EMG activity, compared to normal walking. Greater abdominal muscle activity and ROM of lateral flexion may indicate a specific compensation pattern occurring during stumbling. (C) 2015 Elsevier Ltd. All rights reserved.}, language = {en} } @article{MuellerMuellerStolletal.2016, author = {M{\"u}ller, Juliane and M{\"u}ller, Steffen and Stoll, Josefine and Rector, Michael V. and Baur, Heiner and Mayer, Frank}, title = {Influence of Load on Three-Dimensional Segmental Trunk Kinematics in One-Handed Lifting: A Pilot Study}, series = {Journal of applied biomechanics}, volume = {32}, journal = {Journal of applied biomechanics}, publisher = {Human Kinetics Publ.}, address = {Champaign}, issn = {1065-8483}, doi = {10.1123/jab.2015-0227}, pages = {520 -- 525}, year = {2016}, abstract = {Stability of the trunk is relevant in determining trunk response to different loading in everyday tasks initiated by the limbs. Descriptions of the trunk's mechanical movement patterns in response to different loads while lifting objects are still under debate. Hence, the aim of this study was to analyze the influence of weight on 3-dimensional segmental motion of the trunk during 1-handed lifting. Ten asymptomatic subjects were included (29 ± 3 y; 1.79 ± 0.09 m; 75 ± 14 kg). Subjects lifted 3× a light and heavy load from the ground up onto a table. Three-dimensional segmental trunk motion was measured (12 markers; 3 segments: upper thoracic area [UTA], lower thoracic area [LTA], lumbar area [LA]). Outcomes were total motion amplitudes (ROM;[°]) for anterior flexion, lateral flexion, and rotation of each segment. The highest ROM was observed in the LTA segment (anterior flexion), and the smallest ROM in the UTA segment (lateral flexion). ROM differed for all planes between the 3 segments for both tasks (P < .001). There were no differences in ROM between light and heavy loads (P > .05). No interaction effects (load × segment) were observed, as ROM did not reveal differences between loading tasks. Regardless of weight, the 3 segments did reflect differences, supporting the relevance of multisegmental analysis.}, language = {en} } @article{MuellerEngelMuelleretal.2016, author = {Mueller, Juliane and Engel, Tilman and Mueller, Steffen and Kopinski, Stephan and Baur, Heiner and Mayer, Frank}, title = {Neuromuscular response of the trunk to sudden gait disturbances: Forward vs. backward perturbation}, series = {Journal of electromyography and kinesiology}, volume = {30}, journal = {Journal of electromyography and kinesiology}, publisher = {Elsevier}, address = {Oxford}, issn = {1050-6411}, doi = {10.1016/j.jelekin.2016.07.005}, pages = {168 -- 176}, year = {2016}, abstract = {The study aimed to analyse neuromuscular activity of the trunk comparing four different perturbations during gait. Thirteen subjects (28 +/- 3 yrs) walked (1 m/s) on a split-belt treadmill, while 4 (belt) perturbations (F1, F2, B1, B2) were randomly applied. Perturbations differed, related to treadmill belt translation, in direction (forward (F)/backward (B)) and amplitude (20 m/s(2) (1)/40 m/s(2) (2)). Trunk muscle activity was assessed with a 12-lead-EMG. EMG-RMS [\%] (0-200 ms after perturbation; normalized to RMS of normal gait) was analyzed for muscles and four trunk areas (ventral left/right; dorsal left/right). Ratio of ventral: dorsal muscles were calculated. Muscle onset [ms] was determined. Data analysis was conducted descriptively, followed by ANOVA (post hoc Tukey-Kramer (alpha = 0.05)). All perturbations lead to an increase in EMG-RMS (428 +/- 289\%). F1 showed the lowest and F2 the highest increase for the flexors. B2 showed the highest increase for the extensors. Significant differences between perturbations could be observed for 6 muscles, as well as the 4 trunk areas. Ratio analysis revealed no significant differences (range 1.25 (B1) to 1.71 (F2) between stimuli. Muscle response time (ventral: 87.0 +/- 21.7 ms; dorsal: 88.4 +/- 17.0 ms) between stimuli was only significant (p = 0.005) for the dorsal muscles. Magnitude significantly influences neuromuscular trunk response patterns in healthy adults. Regardless of direction ventral muscles always revealed higher relative increase of activity while compensating the walking perturbations. (C) 2016 Elsevier Ltd. All rights reserved.}, language = {en} } @article{WahmkowCasselMayeretal.2017, author = {Wahmkow, Gunnar and Cassel, Michael and Mayer, Frank and Baur, Heiner}, title = {Effects of different medial arch support heights on rearfoot kinematics}, series = {PLoS one}, volume = {12}, journal = {PLoS one}, number = {3}, publisher = {PLoS}, address = {Lawrence, Kan.}, issn = {1932-6203}, doi = {10.1371/journal.pone.0172334}, year = {2017}, abstract = {Background Foot orthoses are usually assumed to be effective by optimizing mechanically dynamic rearfoot configuration. However, the effect from a foot orthosis on kinematics that has been demonstrated scientifically has only been marginal. The aim of this study was to examine the effect of different heights in medial arch-supported foot orthoses on rear foot motion during gait. Methods Nineteen asymptomatic runners (36±11years, 180±5cm, 79±10kg; 41±22km/week) participated in the study. Trials were recorded at 3.1 mph (5 km/h) on a treadmill. Athletes walked barefoot and with 4 different not customized medial arch-supported foot orthoses of various arch heights (N:0 mm, M:30 mm, H:35 mm, E:40mm). Six infrared cameras and the `Oxford Foot Model´ were used to capture motion. The average stride in each condition was calculated from 50 gait cycles per condition. Eversion excursion and internal tibia rotation were analyzed. Descriptive statistics included calculating the mean ± SD and 95\% CIs. Group differences by condition were analyzed by one factor (foot orthoses) repeated measures ANOVA (α = 0.05). Results Eversion excursion revealed the lowest values for N and highest for H (B:4.6°±2.2°; 95\% CI [3.1;6.2]/N:4.0°±1.7°; [2.9;5.2]/M:5.2°±2.6°; [3.6;6.8]/H:6.2°±3.3°; [4.0;8.5]/E:5.1°±3.5°; [2.8;7.5]) (p>0.05). Range of internal tibia rotation was lowest with orthosis H and highest with E (B:13.3°±3.2°; 95\% CI [11.0;15.6]/N:14.5°±7.2°; [9.2;19.6]/M:13.8°±5.0°; [10.8;16.8]/H:12.3°±4.3°; [9.0;15.6]/E:14.9°±5.0°; [11.5;18.3]) (p>0.05). Differences between conditions were small and the intrasubject variation high. Conclusion Our results indicate that different arch support heights have no systematic effect on eversion excursion or the range of internal tibia rotation and therefore might not exert a crucial influence on rear foot alignment during gait.}, language = {en} }