关节水平的“共驱动”研究

Research of "Common Drive" at Joint Level

本文以主动肌和拮抗肌的协同作用机理为依据,从表面肌电(EMG)信号的频率参数和肌肉平均传导速度两个方面,对近年来提出的正常人体神经肌肉系统控制的新理论——“共驱动”概念,在关节水平上进行了探讨和研究,实验结果表明:膝关节的主动肌和拮抗肌在持续恒力收缩下,其表面EMG信号功率谱的归一化中值频率随着时间的增加而同时下降;两路EMG信号的归一化中值频率之间的互相关系数随着收缩力的减小而减小,肘关节的肱二头肌不论是作为主动肌还是拮抗肌,在持续恒力收缩下,由表面EMG信号估计得到的肌肉的平均传导速度均随着收缩时间的增加而下降;肱二头肌作为拮抗肌时,平均传导速度明显高于其作为主动肌时的平均传导速度。

Based on the mechanisms of agonist-antagonist co-activation, this paper explores the common drive concept in such aspects as frequency paramenter of surface EMG signals and average conduction velocity of muscles. The experimental results show that, when the knee joint contracts at constant force lever, the normalized median frequencies of power density spectrum of the agonist-antagonist surface EMG signals decline with sustaining time, and the cross-correlation coefficients of normalized median frequencies of two channel EMG signals decline as the contraction force decreases. Biceps acting as either the agonists or antagonists, their average conduction velocity decline with sustaining time. The average conduction velocity of the biceps acting as antagonists is much higher than that of those acting as agonists.