Fatigue-related electromyographic coherence and phase synchronization analysis between antagonistic elbow muscles
Fatigue-related electromyographic coherence and phase synchronization analysis between antagonistic elbow muscles
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DOI：
10.1007/s00221-014-4172-x
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发表时间：
2015-03-01
影响因子：
2
通讯作者：
Gong, Mingxin
中科院分区：
文献类型：
--
作者：
Wang, Lejun;Lu, Aiyun;Gong, Mingxin
本研究的目的是检查对抗性肘关节肌肉之间的一致性和相位同步，从而探索对抗性肘关节肌肉在持续次极大等长疲劳收缩期间的耦合和共同神经输入。15名健康男性受试者保持20%的最大肘关节屈曲，直到筋疲力尽，同时收集肱二头肌（BB）和肱三头肌（TB）的表面肌电信号（sEMG）。表面肌电信号分为收缩的前半部分（第1阶段疲劳最小）和后半部分（第2阶段疲劳严重）。对BB和TB的表面肌电信号进行相干性和相位同步分析，得到alpha （8-12 Hz）、beta （15-35 Hz）和gamma （35-60 Hz）频段的相干性值和相位同步指数。与1期相比，2期肌电图-肌电图相干性和α和β频段相同步指数显著增加。20%最大水平持续等距肘关节屈曲引起的疲劳增加了拮抗肌肉之间的肌电图活动耦合，表明同步皮质神经元与BB和TB运动神经元池之间的联系增加，这可能是皮层起源。这种增加的耦合可能有助于维持共激活水平，从而在保持关节力输出的基础上确保关节的稳定性。
The aim of this study was to examine coherence and phase synchronization between antagonistic elbow muscles and thus to explore the coupling and common neural inputs of antagonistic elbow muscles during sustained submaximal isometric fatiguing contraction. Fifteen healthy male subjects sustained an isometric elbow flexion at 20 % maximal level until exhaustion, while surface electromyographic signals (sEMG) were collected from biceps brachii (BB) and triceps brachii (TB). sEMG signals were divided into the first half (stage 1 with minimal fatigue) and second half (stage 2 with severe fatigue) of the contraction. Coherence and phase synchronization analysis was conducted between sEMG of BB and TB, and coherence value and phase synchronization index in alpha (8-12 Hz), beta (15-35 Hz) and gamma (35-60 Hz) frequency bands were obtained. Significant increase in EMG-EMG coherence and phase synchronization index in alpha and beta frequency bands between antagonistic elbow flexion muscles was observed all increased in stage 2 compared to stage 1. Coupling of EMG activities between antagonistic muscles increased as a result of fatigue caused by 20 % maximal level sustained isometric elbow flexion, indicating the increased interconnection between synchronized cortical neurons and the motoneuron pool of BB and TB, which may be cortical in origin. This increased coupling may help to maintain coactivation level so as to ensure joint stability on the basis of maintaining the joint force output.