Electromyographic fatigue threshold of the biceps brachii muscle during dynamic contraction.

The purpose of this study was to identify the Electromyographic Fatigue Threshold (EMGFT) of the biceps brachii muscle bilaterally during the elbow flexion in tests performed in different times. 30 second test, 1 minute test and fatiguing test, in concentric (CC) and eccentric (EC) phases. Nine healthy young men performed the elbow flexion with loads corresponding at 25%, 35% and 45% of the one repetition maximum (1-RM) in separate days. The results indicated that the test applied for the biceps brachii muscle during elbow flexion induced a progressive increment of EMG activity with time indicating muscle fatigue and allowed the identification of the EMGFT. The three tests presented no difference of EMGFT between CC and EC phases bilaterally.