EMG-based detection of muscle fatigue during low-level isometric contraction: effects of electrode configuration and blood flow restriction.

This study assessed muscle fatigue during low-level contraction, which is sometimes difficult to observe. Surface EMG signals were recorded with monopolar and bipolar configurations during low-level isometric muscle contraction under a blood flow restriction condition (BFR condition) and a non-blood flow restriction condition (CON condition). As indices of fatigue, center frequency (CF) of the power spectral density (PSD) of the surface EMG and rating of perceived exertion (RPE) with the Borg CR-10 Scale were used. Results suggested that the monopolar configuration, which has a wider detection area relative than the bipolar one, was well suited for obtaining wave slowing accompanied by muscle fatigue. In addition, the monopolar configuration could detect differences in muscle condition in the BFR and CON conditions.