应用表面肌电图评定优秀竞走运动员20km训练中的肌疲劳

Surface electromyography for assessing muscular fatigue of topnotch walking athletes during 20-kilometer training

目的:通过动态肌电分析方法对20km定量负荷竞走运动员疲劳过程中肌肉的功能状态变化做出评价,找出该运动员的定量负荷疲劳阈值。方法:北京田径队竞走运动员20km定量负荷竞走训练,取全程的表面肌电图信号用Megawin软件进行时、频域分析。对主要做功肌肉股外侧肌和胫骨前肌的表面肌电图(surfaceelectromyography,sEMG)信号进行全程动态分析,计算平均功率频率(meanpowerfrequency,MPF)和平均振幅(averageelectromyography,AEMG)的变化。结果:竞走开始时肌肉放电节奏非常有规律,竞走结束前股外侧肌与胫骨前肌的肌电活动振幅较竞走开始时明显增高;竞走至15km时出现AEMG增高,MPF下降;频域指标MPF与竞走距离呈明显负相关(r=-0.758,P<0.001)。结论:sEMG的AEMG和MPF能反映运动员20km竞走的肌肉功能状况;定量负荷20km竞走运动过程中,该运动员在15km时开始出现肌肉的疲劳。

AIM:To evaluate the muscle functional status of walking athletes during 20-kilometer training with dynamic surface electromyography(sEMG),and search for the athletic muscle fatigue threshold. METHODS:A walking athlete of Beijing Track And Field Team carried out 20-kilometer walking training,and the sEMG signals were recorded.The time and frequency characteristics of sEMG were analyzed by using the Megawin software.The characteristics changes of mean power frequency(MPF) and average amplitude(average electromyography,AEMG) in sEMG signals of the left quadriceps femoris muscle and the left tibialis anterior muscle. RESULTS:The discharge rhythm of muscle at the walking beginning was very regular;the AEMG of quadriceps femoris muscle and tibialis anterior muscle increased and MPF decreased at 15 km; MPF was negatively correlated with the walking distance(r=-0.758,P< 0.001). CONCLUSION:AEMG and MPF can evaluate the muscle functional status of walking athletes during 20-kilometer training; in the 20-kilometer walking,muscular fatigue of this athlete occurred at 15 km of 20-kilometer training.