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 1 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.
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 1 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.
Authors: B O'Connor; M Markicevic; L Newman; R K Poduval; E Tiernan; E Hanrahan; S Cuffe; R B Reilly; D Walsh Journal: Support Care Cancer Date: 2018-11-22 Impact factor: 3.603
Authors: S Floor Campfens; Alfred C Schouten; Michel J A M van Putten; Herman van der Kooij Journal: Exp Brain Res Date: 2013-05-12 Impact factor: 1.972