PDF(Pubmed)
Abstract：
OBJECTIVE: Scapular dyskinesis is one of the causes of shoulder disorders and involves muscle weakness in the serratus anterior. This study investigated whether motor unit (MU) recruitment and firing property, which are important for muscle exertion, have altered in serratus anterior of the individuals with scapular dyskinesis.
METHODS: Asymptomatic adults with (SD) and without (control) scapular dyskinesis were analyzed. Surface electromyography (sEMG) waveforms were collected at submaximal voluntary contraction of the serratus anterior. The sEMG waveform was decomposed into MU action potential amplitude (MUAPAMP), mean firing rate (MFR), and recruitment threshold. MUs were divided into low, moderate, and high thresholds, and MU recruitment and firing properties of the groups were compared.
RESULTS: High-threshold MUAPAMP was significantly smaller in the SD group than in the control group. The control group also exhibited recruitment properties that reflected the size principle, however, the SD group did not. Furthermore, the SD group had a lower MFR than the control group.
CONCLUSIONS: Individuals with scapular dyskinesis exhibit altered MU recruitment properties and lower firing rates of the serratus anterior; this may be detrimental to muscle performance. Thus, it may be necessary to improve the neural drive of the serratus anterior when correcting scapular dyskinesis.
METHODS: Asymptomatic adults with (SD) and without (control) scapular dyskinesis were analyzed. Surface electromyography (sEMG) waveforms were collected at submaximal voluntary contraction of the serratus anterior. The sEMG waveform was decomposed into MU action potential amplitude (MUAPAMP), mean firing rate (MFR), and recruitment threshold. MUs were divided into low, moderate, and high thresholds, and MU recruitment and firing properties of the groups were compared.
RESULTS: High-threshold MUAPAMP was significantly smaller in the SD group than in the control group. The control group also exhibited recruitment properties that reflected the size principle, however, the SD group did not. Furthermore, the SD group had a lower MFR than the control group.
CONCLUSIONS: Individuals with scapular dyskinesis exhibit altered MU recruitment properties and lower firing rates of the serratus anterior; this may be detrimental to muscle performance. Thus, it may be necessary to improve the neural drive of the serratus anterior when correcting scapular dyskinesis.
摘要：
目的：肩胛骨皮肤发育不良是导致肩关节紊乱的原因之一，与前锯肌肌无力有关。这项研究调查了汽车单位(MU)是否招募和射击财产，这对肌肉锻炼很重要，在肩胛骨皮肤发育不良的个体的前锯齿中发生了改变。
方法：分析了有（SD）和没有（对照）肩胛骨发育不良的无症状成年人。在前锯肌的次最大自愿收缩时收集表面肌电图（sEMG）波形。将sEMG波形分解为MU动作电位振幅(MUAPAMP),平均激发率（MFR），招聘门槛。MU分为低位，中度,和高门槛，比较了各组的MU招募和解雇属性。
结果：高阈值MUAPAMP在SD组明显小于对照组。对照组还展示了反映规模原则的招聘属性，然而,SD组没有。此外，SD组的MFR低于对照组。
结论：肩胛骨皮肤发育不良患者表现出改变的MU募集特性和较低的前锯肌放电率；这可能对肌肉性能有害。因此，在矫正肩胛骨发育不全时，可能需要改善前锯齿肌的神经驱动。
方法：分析了有（SD）和没有（对照）肩胛骨发育不良的无症状成年人。在前锯肌的次最大自愿收缩时收集表面肌电图（sEMG）波形。将sEMG波形分解为MU动作电位振幅(MUAPAMP),平均激发率（MFR），招聘门槛。MU分为低位，中度,和高门槛，比较了各组的MU招募和解雇属性。
结果：高阈值MUAPAMP在SD组明显小于对照组。对照组还展示了反映规模原则的招聘属性，然而,SD组没有。此外，SD组的MFR低于对照组。
结论：肩胛骨皮肤发育不良患者表现出改变的MU募集特性和较低的前锯肌放电率；这可能对肌肉性能有害。因此，在矫正肩胛骨发育不全时，可能需要改善前锯齿肌的神经驱动。
