【摘要】 采用实验法,记录受试对象以20%MVC负荷强度静态屈肘诱发肌肉疲劳过程中肱二头肌与肱桡肌的表面肌电信号,并将所记录信号按持续时间均分为2段,对2段信号相干性进行对比分析。研究结果显示:运动后半段相干函数在Beta频段内的值明显大于运动前半段,而Tremor和Gamma频段内无显著性差异,提示疲劳过程中肱二头肌与肱桡肌共神经输入同步支配增加。这或许是为补偿疲劳引起的运动神经元兴奋性下降,大脑运动皮层控制协同肌以更加同步的方式活动,在肌肉收缩能力下降的情况下继续维持既定的负荷运动任务。更多还原

【Abstract】 The study used experiment to record 15 subjects with elbow flexion muscle at 20% maximum voluntary contraction(MVC) to induce muscle fatigue.Surface electromyographic signals(SEMG) were collected from biceps brachii(BB) and brachioradialis(BR).SEMG was divided into two segments and coherence analysis was conducted between BB and BR electromyographic signals in both segments.The results show that coherence in the second half of the fatiguing contraction was significantly larger than that in the first half of the fatiguing contraction in beta frequency band,indicating that common neural input across BB and BR muscles increased in the second half of the fatiguing contraction compared to the first half of the fatiguing contraction.The increase of coherence may help to overcome the reduced motoneuron excitability caused by fatigue and coordinate the force production across muscles in a more synergistic manner as the force generating capacity of the muscles is decreasing.更多还原