【作者】 杨义勇； 王人成； 金德闻； 黄昌华；

【Author】 Yang Yi Yong, Wang Ren Cheng, Jin De Wen.et.al.Dept.of Precision Instruments, Tsinghua University, Beijing, 100084

【机构】 清华大学精密仪器系康复工程中心；

【摘要】 目的 探讨人体上肢肘关节运动中表面肌电信号(EMG)幅值及其功率谱的变化规律.方法 15个样本在其矢状面内做三种类型肘关节屈伸运动,第一种为快速自主运动,第二、三种分别为在屈伸过程中用一根刚性杆在肘关节角为90°时突然限制上臂及手掌的运动和在上臂到达杆之前突然松开控制杆,试验时应用专门研制的肌电信号采集系统将肱二头肌、肱三头肌的肌电信号及相关运动参数输入计算机,利用回归分析和MATLAB语言编程研究肌电信号幅值和功率谱(MPF)的变化规律.结果 突然限制和突然放开这两种有扰运动类型的肌电信号与自主运动的肌电信号随时间的变化曲线有较大差异,且EMG开始变化的时间比自主运动的延迟;同时,试验时间较长导致上肢肌肉疲劳时,肱二头肌的EMG的幅值明显增大而功率谱(MPF)明显下降.结论 人的神经中枢系统对上肢肘关节受扰运动具有预组织、调节、控制功能,会在外部环境的变化中逐步协调肘和腕两个关节成一个协调元适应外部环境;EMG幅值及其功率谱的变化与肌肉力活性、肌肉疲劳之间有确定性的关系.更多还原

【Abstract】 Objective analyses the changes of Surface EMG and the EMG spectral of muscle activation in the upper arm during elbow joint movements. Method The subjects(n = 15) performed series of very fast movements or isometric contractions against a stick at the level of the palm or at the level of the forearm. Some trials within a series of movements were unexpectedly blocked at the 90 position leading to an isometric contraction, while some trials within a series of isometric contractions were unexpectedly released leading to movement. Movement’s kinematics and the surface electromyographic (EMG) patterns of biceps and triceps during elbow joint flexion - extension movements were input to the computer. The mean power frequency(MPF)and average EMG amplitude were calculated using MATLAB software with each sample, and a polynomial regression analysis was used to characterize the EMG spectral changes. Result changes in the EMG patterns in unexpectedly blocked movements or unexpectedly released isometric contractions as compared to unperturbed trials could be seen at a obvious delay. The relative increases of AEMG and decrease of MPF associated with fatigue were significant. Conclusion The common organization of central commands to the elbow and the wrist joints within a two - joint synergy is associated with a similar organization of pre - programmed corrections to unexpected changes in external conditions. According to the relationship between EMG and muscle activation.更多还原