@article{MuellerEngelKopinskietal.2017, author = {M{\"u}ller, Juliane and Engel, Tilman and Kopinski, Stephan and Mayer, Frank and M{\"u}ller, Steffen}, title = {Neuromuscular trunk activation patterns in back pain patients during one-handed lifting}, series = {World journal of orthopedics}, volume = {8}, journal = {World journal of orthopedics}, number = {2}, publisher = {Baishideng Publishing Group}, address = {Pleasanton}, issn = {2218-5836}, doi = {10.5312/wjo.v8.i2.142}, pages = {142 -- 148}, year = {2017}, abstract = {AIM To analyze neuromuscular activity patterns of the trunk in healthy controls (H) and back pain patients (BPP) during one-handed lifting of light to heavy loads. METHODS RESULTS Seven subjects (3m/4f; 32 +/- 7 years; 171 +/- 7 cm; 65 +/- 11 kg) were assigned to BPP (pain grade >= 2) and 36 (13m/23f; 28 +/- 8 years; 174 +/- 10 cm; 71 +/- 12 kg) to H (pain grade <= 1). H and BPP did not differ significantly in anthropometrics (P > 0.05). All subjects were able to lift the light and middle loads, but 57\% of BPP and 22\% of H were not able to lift the heavy load (all women) chi(2) analysis revealed statistically significant differences in task failure between H vs BPP (P = 0.03). EMG-RMS ranged from 33\% +/- 10\%/30\% +/- 9\% (DL, 1 kg) to 356\% +/- 148\%/283\% +/- 80\% (VR, 20 kg) in H/BPP with no statistical difference between groups regardless of load (P > 0.05). However, the EMG-RMS of the VR was greatest in all lifting tasks for both groups and increased with heavier loads. CONCLUSION Heavier loading leads to an increase (2-to 3-fold) in trunk muscle activity with comparable patterns. Heavy loading (20 kg) leads to task failure, especially in women with back pain.}, language = {en} } @article{BaritelloKhajooeiEngeletal.2020, author = {Baritello, Omar and Khajooei, Mina and Engel, Tilman and Kopinski, Stephan and Quarmby, Andrew James and M{\"u}ller, Steffen and Mayer, Frank}, title = {Neuromuscular shoulder activity during exercises with different combinations of stable and unstable weight mass}, series = {BMC sports science, medicine and rehabilitation}, volume = {12}, journal = {BMC sports science, medicine and rehabilitation}, number = {1}, publisher = {BioMed Central}, address = {London}, issn = {2052-1847}, doi = {10.1186/s13102-020-00168-x}, pages = {14}, year = {2020}, abstract = {Background Recent shoulder injury prevention programs have utilized resistance exercises combined with different forms of instability, with the goal of eliciting functional adaptations and thereby reducing the risk of injury. However, it is still unknown how an unstable weight mass (UWM) affects the muscular activity of the shoulder stabilizers. Aim of the study was to assess neuromuscular activity of dynamic shoulder stabilizers under four conditions of stable and UWM during three shoulder exercises. It was hypothesized that a combined condition of weight with UWM would elicit greater activation due to the increased stabilization demand. Methods Sixteen participants (7 m/9 f) were included in this cross-sectional study and prepared with an EMG-setup for the: Mm. upper/lower trapezius (U.TA/L.TA), lateral deltoid (DE), latissimus dorsi (LD), serratus anterior (SA) and pectoralis major (PE). A maximal voluntary isometric contraction test (MVIC; 5 s.) was performed on an isokinetic dynamometer. Next, internal/external rotation (In/Ex), abduction/adduction (Ab/Ad) and diagonal flexion/extension (F/E) exercises (5 reps.) were performed with four custom-made-pipes representing different exercise conditions. First, the empty-pipe (P; 0.5 kg) and then, randomly ordered, water-filled-pipe (PW; 1 kg), weight-pipe (PG; 4.5 kg) and weight + water-filled-pipe (PWG; 4.5 kg), while EMG was recorded. Raw root-mean-square values (RMS) were normalized to MVIC (\%MVIC). Differences between conditions for RMS\%MVIC, scapular stabilizer (SR: U.TA/L.TA; U.TA/SA) and contraction (CR: concentric/eccentric) ratios were analyzed (paired t-test; p <= 0.05; Bonferroni adjusted alpha = 0.008). Results PWG showed significantly greater muscle activity for all exercises and all muscles except for PE compared to P and PW. Condition PG elicited muscular activity comparable to PWG (p > 0.008) with significantly lower activation of L.TA and SA in the In/Ex rotation. The SR ratio was significantly higher in PWG compared to P and PW. No significant differences were found for the CR ratio in all exercises and for all muscles. Conclusion Higher weight generated greater muscle activation whereas an UWM raised the neuromuscular activity, increasing the stabilization demands. Especially in the In/Ex rotation, an UWM increased the RMS\%MVIC and SR ratio. This might improve training effects in shoulder prevention and rehabilitation programs.}, language = {en} } @misc{BaritelloKhajooeiEngeletal.2020, author = {Baritello, Omar and Khajooei, Mina and Engel, Tilman and Kopinski, Stephan and Quarmby, Andrew James and M{\"u}ller, Steffen and Mayer, Frank}, title = {Neuromuscular shoulder activity during exercises with different combinations of stable and unstable weight mass}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {1}, issn = {1866-8364}, doi = {10.25932/publishup-50936}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-509366}, pages = {16}, year = {2020}, abstract = {Background Recent shoulder injury prevention programs have utilized resistance exercises combined with different forms of instability, with the goal of eliciting functional adaptations and thereby reducing the risk of injury. However, it is still unknown how an unstable weight mass (UWM) affects the muscular activity of the shoulder stabilizers. Aim of the study was to assess neuromuscular activity of dynamic shoulder stabilizers under four conditions of stable and UWM during three shoulder exercises. It was hypothesized that a combined condition of weight with UWM would elicit greater activation due to the increased stabilization demand. Methods Sixteen participants (7 m/9 f) were included in this cross-sectional study and prepared with an EMG-setup for the: Mm. upper/lower trapezius (U.TA/L.TA), lateral deltoid (DE), latissimus dorsi (LD), serratus anterior (SA) and pectoralis major (PE). A maximal voluntary isometric contraction test (MVIC; 5 s.) was performed on an isokinetic dynamometer. Next, internal/external rotation (In/Ex), abduction/adduction (Ab/Ad) and diagonal flexion/extension (F/E) exercises (5 reps.) were performed with four custom-made-pipes representing different exercise conditions. First, the empty-pipe (P; 0.5 kg) and then, randomly ordered, water-filled-pipe (PW; 1 kg), weight-pipe (PG; 4.5 kg) and weight + water-filled-pipe (PWG; 4.5 kg), while EMG was recorded. Raw root-mean-square values (RMS) were normalized to MVIC (\%MVIC). Differences between conditions for RMS\%MVIC, scapular stabilizer (SR: U.TA/L.TA; U.TA/SA) and contraction (CR: concentric/eccentric) ratios were analyzed (paired t-test; p <= 0.05; Bonferroni adjusted alpha = 0.008). Results PWG showed significantly greater muscle activity for all exercises and all muscles except for PE compared to P and PW. Condition PG elicited muscular activity comparable to PWG (p > 0.008) with significantly lower activation of L.TA and SA in the In/Ex rotation. The SR ratio was significantly higher in PWG compared to P and PW. No significant differences were found for the CR ratio in all exercises and for all muscles. Conclusion Higher weight generated greater muscle activation whereas an UWM raised the neuromuscular activity, increasing the stabilization demands. Especially in the In/Ex rotation, an UWM increased the RMS\%MVIC and SR ratio. This might improve training effects in shoulder prevention and rehabilitation programs.}, language = {en} } @inproceedings{KopinskiEngelMuelleretal.2013, author = {Kopinski, Stephan and Engel, Tilman and M{\"u}ller, Steffen and Mayer, Frank}, title = {Torque-EMG relationship of lower back muscles - a pilot study}, series = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine}, volume = {45}, 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 = {7 -- 8}, year = {2013}, language = {en} } @inproceedings{EngelMuellerMuelleretal.2013, author = {Engel, Tilman and M{\"u}ller, Juliane and M{\"u}ller, Steffen and Reschke, Antje and Kopinski, Stephan and Mayer, Frank}, title = {Validity and reliability of a new customised split-belt treadmill provoking unexpected walking perturbations}, series = {Medicine and science in sports and exercise : official journal of the American College of Sports Medicine}, volume = {45}, 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 = {462 -- 462}, year = {2013}, language = {en} } @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} }