【摘要】 目的应用表面肌电图(surface electromyography,sEMG)测量青少年足球运动员在训练赛中股直肌的情况,并结合神经系统疲劳指标反应时对运动员疲劳状态做出评估。方法重庆U20足球运动员3次90 min常规比赛,每场间隔7天。通过BL-420S生物机能系统测量两个试验阶段经双腿下蹲的股直肌sEMG信号,并结合自制光反射测量仪测量两个实验阶段的反应时。记录反应时并在MATLAB7.0编程软件下处理sEMG信号,算出平均功率频率(mean power frequency,MPF)和均方根振幅(root mean square,RMS)。两个实验阶段的频域值、时域值和反应时的差异利用配对样本t检验进行统计处理,反应时与sEMG各指标做相关性分析。结果 U20青少年足球运动员第二实验阶段的MPF比第一实验阶段的明显降低(P<0.05),具有较显著差异,同时在第二实验阶段的RMS和反应时比第一实验阶段增高(P<0.05),均具有较显著差异。相关性分析中反应时与MPF呈负相关,与RMS呈正相关。结论 sEMG和反应时有明显的相关性,联合应用可以反应运动员训练前后神经肌肉系统的机能状况。更多还原

【Abstract】 Objective To evaluate the fatigue of the juvenile football players,rectus femoris after regular football games by surface electromyography(sEMG),combined with response latencies(RL)of nervous system fatigue-index for players to assess fatigue state.Method Chongqing U20 juvenile football players played 90 minutes games for 3 times.Each football game was separated by 7 days.To test the two phases,sEMG signals of squat legs by BL-420 S data acquisition &analysis system,and measure RL by self-made light reflex measuring instrument.Recorded the RL and analyzed the mean power frequency(MPF),root mean square(RMS)under MATLAB7.0 programming software.The difference in the frequency and time value were analyzed statistically with paired-sample T test.Response latencies was done correlation analysis with sEMG.Results Compared with the beginning phase,the MPF of U20 juvenile football players in the ending phase decreased significantly(P<0.05),and the RMS,RL of the same players in the ending phase increased significantly(P<0.05).In the correlation analysis the response latencies had negative correlation with MPF,and the response latencies were positively related to the RMS.Conclusion sEMG and response latencies have obvious correlation,the combination of them can represent the neuromuscular system before and after training.更多还原