未经训练成年男性急性运动性疲劳的电刺激研究

Study on the Electrical Stimulation of Motility Muscle Fatigue for Untrained Adult Male

运用电刺激的方法研究未经训练成年男性的急性运动性疲劳机制。结果表明:在疲劳性伸膝运动后,最大随意收缩力下降17±15%(p<0.001),中枢激活水平从88±7%下降到84±6%(p=0.001),M波波幅基本不变,但电刺激诱发的最大颤搐张力和最大张力上升速度明显降低,半舒张时间延长,激活后增强效应(postactivation potentiation)下降19%(p<0.001)。疲劳过程中平均肌电图-力矩比值升高。结论:在未经训练成年男性间歇性大负荷运动导致疲劳过程中,中枢神经系统及肌肉本身均参与了运动性疲劳的形成,肌肉的兴奋性未发生明显变化,但收缩能力减弱。

To investigate exercise-induced muscle fatigue in untrained men by electrical stimulation. The results shows that after KEE, maximal voluntary contraction decreased 17±15% （p〈0.001）, activation level reduced from 88±7% to 84±6% （p=0.001）, the amplitude of M-wave did not change, but peak twitch tension and maximal rate of force development weakened with lengthened half-relaxation time. Postactivation potentiation decreased 19%（p〈0.001）. AEMG-torque ratio increased during fatigue. We can Conclusion that both central nervous system and muscle contractility contributed to fatigue development. Muscle excitability could be maintained in this intermittent KEE and therefore might not be the main cause of the fatigue.