最大等长收缩过程中及恢复期表面肌电信号的变化

The Change of sEMG During Isometric Maximal Voluntary Contraction(MVC) and the Recovery Phase

为了了解sEMG信号在运动诱发的疲劳恢复期内的规律,本研究以肱二头肌持续最大收缩至肌力下降到初始值的50%以及恢复期120秒内不同时刻获得的sEMG信号为研究对象,采用线性和非线性分析方法(FFT和RQA)计算出AEMG、MF和Determ%这些指标以及肌力(MVC)的变化情况。结果发现,在等长收缩过程中,AEMG迅速增加然后呈线性递减,MF从收缩的一开始一直呈现出线性下降的变化模式,而Determ%除了第1个值显著大于第2个外,其余表现出线性递增的变化模式。在恢复期内,AEMG的变化没有明显的规律性,MF随着和Determ%均表现出良好的恢复趋势。MF和Determ%为半时恢复期为12.9和5.2秒,显著低于MVC的19.2秒。在恢复期内没有出现在等长收缩过程中的第1段信号的Determ%大于第2段信号的情形。研究提示,sEMG信号可能更主要受CNS对肌肉控制策略的影响,Determ%的变化可能揭示包含肌肉功能状态的生物学信息。

In order to investigate the regularity of SEMG signal in recovery phase after sustained maximal contraction till force decreased less than 50% MVC, this study analyed MVC changes and sEMG signal of BB during contraetion and recovery phase of 120 ,seconds use linear and non- linear methods （FFT and RQA） to get AEMG, MF, Determ%. We founded that AEMG increased rapidly then decreased linearly during contracting phase while MF decreased all the time. Determ% showed a linear increasing trend except that the first value was significantly greater than the second one. But this phenomena were not seen in the recovery phase. In the recovery phase MF and Determ% showed good regularity except AEMG. T1/2 of MF and Determ% were 12.9s and 5.2s respectively and were significantly smaller than 19.2s of MVC. The study suggested that sEMG signal was mainly affected by controlling strategy of CNS, and the changes of Determ% may contain some biological messages of muscle function.