递增负荷诱发肌肉疲劳过程中肌肉sEMG与负荷的非线性关系研究

Non-linear relationship between muscle sEMG and exercise load during the process of increasing load induced muscle fatigue

目的:明确递增负荷诱发肌肉疲劳过程中肌肉表面肌电信号的变化规律,探索递增负荷诱发肌肉疲劳过程中肌肉的力—电关系。方法:利用蹬踏功率自行车递增负荷方式诱发肌肉疲劳,运用曲线拟合方法探索运动性肌肉疲劳过程中的力—电关系。结果:在递增负荷疲劳模型中,频域指标表现出随运动负荷增大而增大,而后降低的特征;时域指标表现出随运动负荷增大而增大,并逐步达到平台的特征;该过程中肌肉的表面肌电信号与负荷之间表现出三次函数关系。结论:在递增负荷过程中,可以利用肌电信号的拐点作为局部肌肉疲劳的判定标准,在递增负荷初期肌电信号的变化主要与中枢机制有关,后期则主要与外周机制有关。

Objective ： To determine the variation of muscle sEMG while incremental load induced mus- cle fatigue, explore the strength - power relationships during the process. Methods：Exercise on SRM power bicycle in the incremental load method to induce muscle fatigue, use curve fitting meth- od to explore the force - electric relationships during the process. Results： In the incremental load fatigue model, the frequency domain index increased with the exercise load first, then decreased; the time domain index increased with exercise load but gradually achieved a platform; during the process, the sEMG and muscle load present in the cubic function. Conclusions ： In the process of in- creasing load, the inflection point of mechanical and electrical signals can be used as the criterion of local muscle fatigue, at the initial stage of incremental load, the change of EMG mainly related to the central mechanisms;at the latter period, it mainly connected to the peripheral mechanisms.