运动性肌肉疲劳过程中主动肌与拮抗肌sEMG相干性分析  

Exercise Fatigue Related Electromyographic Coherence Analysis between Antagonistic Elbow Muscles

作　　者：王乐军[1] 黄勇[1] 龚铭新[1] 毋江波[1] 李占强[1] 岳增科[1] 

机构地区：[1]同济大学体育部运动与健康研究中心

出　　处：《体育科学》2011年第10期79-84,F0003,共7页China Sport Science

摘　　要：目的:通过静态疲劳负荷实验过程中主动肌与拮抗肌sEMG的相干性分析探索运动性肌肉疲劳过程中中枢神经系统对主动肌与拮抗肌共神经输入(common neural inputs)同步支配的变化特征。方法:以10名健康男性青年志愿者为研究对象,记录受试者以50%MVC负荷强度静态屈肘运动诱发肌肉疲劳过程中主动肌肱二头肌与拮抗肌肱三头肌的sEMG,为考查疲劳因素对相干性分析结果的影响作用,对记录的sEMG按运动持续时间平均分为两段,分别对两段sEMG进行相干性分析处理。结果:在疲劳负荷实验过程中,肱二头肌与肱三头肌MF指标随运动持续时间表现出显著性的单调递减变化趋势。从相干性分析结果看,在beta频段和gamma频段内,运动后半段肱二头肌与肱三头肌sEMG相干函数值要明显小于运动前半段,而tremor频段内无显著性差异。结论:在50%MVC静态负荷屈肘运动致肌肉疲劳过程中,随着负荷运动持续时间的增加,中枢神经系统对主动肌肱二头肌与拮抗肌肱三头肌共神经输入同步支配下降,这可能是由于主动肌与拮抗肌脊髓运动神经元兴奋性及运动皮层对脊髓运动神经元激活能力随疲劳发展的下降不同步性及为维持既定的收缩负荷,中枢神经系统对主动肌与拮抗肌运动单位的募集策略采取不同的调节方式造成的。Objective： The aim of this study was to examine coherence oetween aniagonm.c elbow muscles and thus to explore the characteristics of common neural inputs to co-contracting antagonistic elbow muscles during sustained isometric fatiguing contraction. Method： Ten healthy male subjects participated in this study. With elbow flexion muscle at 50% maximum voluntary contraction （MVC） to induce muscle fatigue, surface electromyographic signals （sEMG） was collected from biceps brachii （BB） and triceps brachii （TB）. sEMG was divided into two segments and coherence analysis was conducted between BB and TB electromyographic signals in both segments. Result： A significant decrease in EMG-EMG coherence in the beta and gamma frequency bands was observed in the second half of the fatiguing contraction com- pared to the first half of the fatiguing contraction. No significant difference was observed in the tremor band coherence between the first and the second half of the fatiguing contraction. Con- clusion： During the sustained isometric fatiguing contraction following the target force level at 50% MVC,common neural input across BB and TB muscles decreased in the second half of the fatigue contraction compared to the first half of the fatiguing contraction, which might be related to asynchronism of failure to activate spinal motoneurons and reduction in motoneuron excitability in antagonistic elbow muscles following muscle fatigue and different motor unit re- cruitment patterns was adopted to coordinate force generation which may help to maintain the target force level more efficiently as the muscle fatigues.

关 键 词：运动性肌肉疲劳 主动肌 拮抗肌 表面肌电信号 相干性分析 

分 类 号：G804.63[文化科学—运动人体科学]