蹲跳、反向跳和下落跳的膝关节屈伸肌群肌电信号分析

目的：通过观察肌电图（EMG）的变化,了解运动员与普通中学生在纵跳过程中,膝关节屈伸肌群工作特点,为运动员科学选材提供依据。方法：30名男女青少年运动员和30名男女普通中学生进行各种形式纵跳（蹲跳、反向跳、下落跳）,测试膝关节屈伸肌群的EMG变化情况。结果：主动肌（股外肌）EMG的变化存在性别差异,随着下肢工作强度的增加,男运动员积分肌电图（iEMG)和平均功率频率（Fmean)均没有显著变化,女运动员iEMG增加,Fmean没有显著变化,对抗肌（股二头肌）,随着下肢工作强度的增加。青少年运动员EMG活动变化较小,而普通中学生的EMG活动明显增加。结论：在增加工作负荷的过程中,男运动员膝关节伸肌群以提高效率为主,女运动员以提高肌肉的募集数量为主;运动员的对抗肌协调水平高于普通中学生。

Electromyogram analyses of the knee flexors and extensor for squatting jump, counter-movement jump and drop jump

Aim: To observe the difference of EMG features between junior athletes and general students of knee flexor and extensor in performing various jumps. Methods: 30 junior athletes and 30 middle school students took part in the test. EMG signal from knee flexor and extensor were measured, when subjects performed squatting jump, counter movement jump and drop jump. Results: The results indicated that the agonists EMG activity related to sex. With the load of leg increasing,there were no significant changes in iEMG and Fmean for male.There was some increasing in iEMG but no change in Fmean for female. The antagonists EMG activity maybe related to training. With the load of leg increasing, the EMG activity of antagonists changed slightly for the junior athletes, however, increased obviously for the common students. Conclusion: To improve the performance of jump, male athletes should mostly improve efficiency, however female athletes can increase the recruiting of muscle fiber. Moreover the ability of antagonists coordinating for athlete in the course of jumping is higher than that of general students.