Department of Sports Science, College of Education, Zhejiang University, Hangzhou 310058, China.
Ningbo Innovation Center, Zhejiang University, Ningbo 315100, China.
J Electromyogr Kinesiol. 2024 Oct;78:102918. doi: 10.1016/j.jelekin.2024.102918. Epub 2024 Aug 26.
The study investigated the effects of unilateral and bilateral lower extremity fatigue on both postural stability and postural adjustments. Fourteen young male subjects performed unilateral and bilateral dynamic lower extremity pedaling exercises with 5 sets of 20 times at 50 % maximum voluntary contraction. Center of pressure (COP) signals were recorded before and after the fatigue exercise. Electromyography activities of six trunk and leg muscles were recorded and analyzed during the anticipatory (APAs) and compensatory (CPAs) postural adjustments. The results showed that both fatiguing exercises caused an increase in COP and larger APAs and CPAs in the rectus femoris and tibialis anterior during externally initiated perturbation. However, the observed indicators showed no clear difference between unilateral and bilateral fatigue. These results validated that when enlarged APAs were not sufficient to resist the external perturbation, the central nervous system increased the strength of CPAs to maintain the stability of the body. These findings provided a perspective on the association between APAs and CPAs, which may apply to the athletic training or rehabilitation on postural control.
本研究旨在探讨单侧和双侧下肢疲劳对姿势稳定性和姿势调整的影响。14 名年轻男性受试者进行了单侧和双侧下肢动态踩踏运动，每组 5 次，每次 20 次，达到最大自主收缩的 50%。在疲劳运动前后记录了中心压力（COP）信号。在外部触发的扰动过程中，记录并分析了 6 块躯干和腿部肌肉的肌电图活动。结果表明，两种疲劳运动都会导致 COP 增加，并且在股直肌和胫骨前肌的预期性和补偿性姿势调整中，APAs 和 CPAs 增大。然而，在单侧和双侧疲劳之间，观察到的指标没有明显差异。这些结果证实，当增大的 APAs 不足以抵抗外部扰动时，中枢神经系统会增加 CPAs 的强度，以维持身体的稳定性。这些发现为 APAs 和 CPAs 之间的关联提供了一个视角，这可能适用于姿势控制的运动训练或康复。
