OBJECTIVETo explore the response of electroencephalography (EEG) signal to biceps brachii fatiguing induced by sustained isometric (non-maximal) voluntary contraction (non-MVC) and to lay a foundation for effective and reliable fatigue evaluation system and for understanding fatigue mechanisms.

METHODSTen male undergraduates performed two different isometric fatiguing tasks with the elbow flexion muscles under a load of 5 and 10 kg respectively, and synchronously EEG signals were collected from scalp. Then amplitude, spectral and Lempel-Ziv complexity C(n) of EEG were calculated.

RESULTSThe average EEG(AEEG) increased while the average mean power frequency (MPF) and complexity of EEG decreased in muscle fatigue. Furthermore, this phenomenon was distributed evenly across the entire scalp, but load only influenced AEEG, MPF and C(n) at Fz.

CONCLUSIONAEEG of EEG increases generally while MPF and C(n) increase generally during local muscle fatigue. This pattern of EEG reflects the central mechanism of muscle fatigue. AEEG, MPF and C(n) at prefrontal area show load dependence.