连续递增负荷条件下肌肉活动的力-电关系

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

目的:观察非疲劳状态下肱二头肌在静态连续递增负荷下sEMG信号的线性和非线性指标变化规律,探讨非疲劳状态下肌肉活动的力-电关系。方法:记录11名男性受试者肱二头肌在完成为时5s连续递增负荷等长收缩过程中的sEMG信号,观察线性分析指标AEMG、MPF、MF与非线性分析指标C(N)和DET%的变化规律。结果:AEMG由第1s的112.14μV逐渐上升到第5s的1277.18μV,与负荷水平呈明显线性相关;DET%从第1s的74.95下降到第5s的46.78,呈单调递减变化;MPF、MF和C(N)在本试验条件下未发生明显改变。结论:在连续递增收缩过程中,线性分析指标AEMG呈线性递增性变化,而MPF和MF无显著改变;非线性分析指标DET%随用力程度的连续递增而递减,而C(N)则保持相对稳定。

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 μV to 1277.18 μV 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.