跑步疲劳进程中人体下肢肌肉协同模式变化

关键词：跑步  运动疲劳  无线表面肌电  神经肌肉控制

Keywords:running  exercise fatigue  surface electromyography  neuromuscular control

摘要：

      摘要 目的：探究跑步疲劳进程中人体下肢肌肉协同模式变化，以揭示人体中枢系统调节下肢动作以适应疲劳积累的机制。 方法：11例男性跑者接受恒定速度跑疲劳干预，并全程采集干预过程时其下肢肌电数据。运用非负矩阵分解算法提取不同干预时刻受试下肢肌肉协同元参与数量、肌肉协同元峰值激活用时、肌肉相对权重等分析指标。 结果：①在肌肉协同元参与数量方面，在整个跑步疲劳干预过程中，共解析出6类肌肉协同元主导人体下肢关节活动，每位受试者平均会从中随机调动4—5类肌肉协同元参与跑步活动，且随着疲劳积累肌肉协同元参与数量无显著变化（P>0.05）。②在肌肉协同元峰值激活用时变化方面，协同元1的峰值激活用时在33%、100%时刻显著降低（P<0.05）。③在肌肉相对权重变化方面，协同元1的半腱肌的相对权重在33%、67%、100%时刻显著降低（P<0.05）。协同元2的股直肌的相对权重在33%时刻显著降低（P<0.05）。协同元4的股二头肌的相对权重在67%时刻显著降低（P<0.05），但在100%时刻显著回升（P<0.05）。 结论：跑步疲劳进程中人体中枢系统会调控下肢肌肉协同模式，以适应疲劳累积，降低下肢损伤风险。该调控过程具体表现：稳定下肢肌肉协同元参与数量，减少早期支撑阶段的肌肉协同元峰值激活用时，动态调节跑步早期支撑阶段的股直肌与半腱肌，中期摆动阶段股二头肌的相对权重。

Abstract:

      Abstract Objective： To explore the changes in the synergy mode of human lower limb muscles during the fatigue running， in order to reveal the mechanism by which the central system regulates lower limb movement to adapt to fatigue accumulation. Method： Eleven male runners received constant speed running fatigue intervention, and the electromyographic data of the lower limb muscles was collected during the whole intervention process. The non-negative matrix factorization algorithm was used to extract analysis indicators such as the number of lower limb muscle synergists，the peak activation time of muscle synergists， and the muscle relative weight at different intervention times. Result：A total of six types of muscle synergists were analyzed throughout the entire process of running fatigue intervention to dominate human lower limb joint activities， but each subject would only randomly mobilize four to five of them at different fatigue moments， and the number of muscle synergists participating in each fatigue moment had no significant change （P>0.05）. The peak activation time of synergy 1 decreased significantly at 33%、100% time （P<0.05）. The relative weight of semitendinosus of synergy 1 was significantly reduced at 33%、67% and 100% time （P<0.05）. The relative weight of rectus femoris of synergy 2 decreased significantly at 33% time （P<0.05）. The relative weight of biceps femoris of synergy 4 decreased significantly at 67% time （P<0.05）， but increased significantly at 100% time （P<0.05）. Conclusion： In the process of running fatigue， the human central system will regulate the muscle synergy mode of lower limbs to adapt to fatigue accumulation and reduce the risk of lower limb injury. The specific performance of this regulation process includes: stabilizing the number of lower limb muscle synergists involved， reducing the peak activation time of muscle synergists in the early stance stage，dynamically adjusting the relative weight of rectus femoris and semitendinosus in the early stance stage and biceps femoris in the middle swing stage.