[The sEMG-force relationship during ramp contractions of biceps brachii in non-fatigue exercises].

OBJECTIVE: To evaluate the capability of C(N) and determinism% (DET%) together with the linear indices, we detected the surface electromyography (sEMG) signal changes during ramp contractions of biceps brachii. METHODS: 5 seconds sEMG signals of 11 male volunteers were recorded to analyze its changes of the linear indices AEMG, mean power frequency(MPF), MF and the non-linear indices C (N), DET%. RESULTS: Average electromyography (AEMG) inclined linearly from 112.14 microV to 1277.18 microV while DET% displayed an decrease from 74.95 to 46.7 during the 5 voluntary contractions. The spectrum parameters MPF/MF and C(N) leveled off with the increasing of the force. CONCLUSION: The linear index AEMG inclined linearly while MPF and MF leveled off with the increasing of the force. The non-linear index DET% declined while C(N) leveled off during the 5 seconds ramp contractions.