Weakening of functional corticomuscular coupling during muscle fatigue

作者：Yang Qi; Fang Yin; Sun Chang Kai; Siemionow Vlodek; Ranganathan Vinoth K; Khoshknabi Dilara; Davis Mellar P; Walsh Declan; Sahgal Vinod; Yue Guany H^*

来源：Brain Research, 2009, 1250: 101-112.

DOI：10.1016/j.brainres.2008.10.074

• Muscle fatigue
• EEG-EMG coherence
• Corticomuscular coupling
• Elbow flexion
• Power of frequency

Objective: Recent research has shown dissociation between changes in brain and muscle signals during voluntary muscle fatigue, which may suggest weakening of functional corticomuscular coupling. However, this weakening of brain-muscle coupling has never been directly evaluated. The purpose of this study was to address this issue by quantifying EEG-EMG coherence at times when muscles experienced minimal versus significant fatigue. Methods: Nine healthy subjects sustained an isometric elbow flexion at 30% maximal level until exhaustion while their brain (EEG) and muscle (EMG) activities were recorded. The entire duration of the EEG and EMG recordings was divided into the first half (stage 1 with minimal fatigue) and second half (stage 2 with severer fatigue). The EEG-EMG coherence and power spectrum in each stage was computed. Results: The power of both EEG and EMG increased significantly while their coherence decreased significantly in stage 2 compared with stage I at beta (15-35 Hz) band. Conclusions: Despite an elevation of the power for both the EEG and EMG activities with muscle fatigue, the fatigue weakens strength of brain-muscle signal coupling at beta frequency band. Significance: Weakening of corticomuscular coupling may be a major neural mechanism contributing to muscle fatigue and associated performance impairment.

• 出版日期2009-1-23
• 单位大连医科大学