运动性肌肉疲劳的表面肌电非线性信号特征

Nonlinear Signal Character of Surface Electromyography of Exercise Muscle Fatigue

研究目的在于探讨不同强度等长运动诱发肌肉疲劳过程中s EMG非线性信号变化特征及其与肌肉运动耐力的关系。10名青年大学生志愿者参加本次实验。采用4 0 %、6 0 %和80 %MVC强度的等长运动试验诱发肱二头肌疲劳,同步采集该肌肉s EMG信号并进行非线性C(n)和% DET和线性MPF分析。研究发现1)肌肉疲劳过程中s EMG信号的MPF和C(n)呈单调递减型变化,而% DET呈单调递增型变化;2 )不同强度运动负荷诱发肌肉疲劳过程中MPF、C(n)和% DET变化率具有明显的运动强度依赖性并与肌肉耐力运动成绩高度相关;3)以% DET变化率反映运动性肌肉疲劳的敏感度明显高于MPF和C(n)。

This study was particularly designed to evaluate the relation between character of sEMG signal and muscle exercise endurance at different intensity during exhaustive isometric muscle contraction.Ten young volunteer college students participated this experiment.With elbow flexion muscle at 40%,60% and 80% maximum voluntary contraction to induce muscle fatigue,sEMG signals was collected from biceps brachi and both linear mean power frequency and nonlinear lempel-Ziv complexity and determinism were calculated during entire experiment.The result showed that both linear mean power frequency and nonlinear lempel-Ziv complexity decreased while determinism increased during muscle fatigue.The change of linear mean power frequency nonlinear lempel-Ziv complexity and determinism had significant load dependence and correlated with muscle endurance time.Determinism showed much higher sensitivity in describing muscle fatigue comparing with other sEMG parameters.