体力负荷诱发的局部肌肉疲劳自发脑电信号改变的特征

Response of electroencephalography to isometric exercise-induced local muscle fatigue

目的探讨不同负荷强度诱发肱二头肌疲劳过程中自发脑电（EEG）信号的变化特征、疲劳的机制及客观评价方法。方法被试者为10名健康男性大学生,采用5和10 kg强度的静态负荷诱发肱二头肌疲劳,并同步在头皮采集128导脑电信号;采集的脑电信号用时频、复杂度信号分析方法进行分析。结果肌肉疲劳过程中平均脑电值（AEEG）均值增加,平均功率频率值（MPF）和脑电信号复杂度[C（n）]均值下降,该现象广泛分布于整个大脑皮层;运动负荷强度对Fz电极的AEEG、MPF和C（n）有明显影响。结论静态负荷诱发肌肉疲劳过程中EEG信号的AEEG呈整体增加趋势,而MPF和C（n）呈整体下降趋势,EEG的这种变化模式反映了疲劳的中枢机制;运动负荷强度依赖性只出现在额叶。

Objective To explore the response of electroencephalography（EEG） signal to biceps brachn fatiguing induced by sustained isometric non-maximal voluntary contraction（non-MVC） and to lay a foundation for effective and reliable fatigue evaluation system and for understanding fatigue mechanisms. Methods Ten male undergraduates performed two different isometric fatiguing tasks with the elbow flexion muscles under a load of 5 and 10 kg respectively, and synchronously EEG signals were collected from scalp. Then amplitude, spectral and Lempel-Ziv complexity C（n） of EEG were calculated. Results The average EEG（AEEG） increased while the average mean power frequency（MPF） and comprexity of EEG decreased in muscle fatigue. Furthermore,this phenomenon was distributed evenly across the entire scalp, but load only influenced AEEG, MPF and C（n） at Fz. Conclusion AEEG of EEG increases generally while MPF and C（n） increase generally during local muscle fatigue.This pattern of EEG reflects the central mechanism of muscle fatigue.AEEG, MPF and C （n） at prefrontal area show load dependence.