基于肌肉机械功的异常步态分析

Abnormal gait analysis based on muscle mechanical work

目的通过量化背屈肌和跖屈肌之间的协同作用分析不同行走速度下偏瘫受试者踝关节角度的异常,以深层次地分析患者的运动功能。方法将从肌电(electromyograph,EMG)驱动的人体肌肉骨骼模型中获得的肌力、力臂和关节角度参数进行预处理,利用肌力和力臂差计算患侧跖屈肌群和背屈肌群做功情况,以此分析由踝关节角度曲线反映出的步态异常。结果跖屈肌群(主要是比目鱼肌和腓肠肌)过度活跃做正功,保持高强度向心收缩,背屈肌群(主要是胫骨前肌)无力几乎不做功导致肌肉协同失衡,从而引起步态异常。结论本文提出的量化肌肉机械功方法可以深层次地分析肌肉之间的协同作用,对于偏瘫患者异常步态的分析具有重要的意义。

Objective The abnormal ankle angles of the subject are analyzed by quantizing the coordination between ankle dorsal and plantar flexors at different speeds to further analyze the patients’motor function.Methods The muscle strength,arm and joint angle obtained from the EMG-driven human musculoskeletal model are pre-processed,and the mechanical work of the dorsal and plantar flexors of hemiplegia side calculated by muscle strength and force arm difference are used to explain the anomaly reflected by the ankle joint angle curve.Results The plantar flexors are overactive and doing positive work,maintaining high-intensity centripetal contraction(mainly soleus and gastrocnemius)and the dorsal flexors weakness are almost unworked(mainly the tibialis anterior muscle)cause muscle coordination imbalance,leading to abnormal gait.Conclusions The method of quantitative muscle mechanical work proposed in this paper can deeply analyze the coordination relationship between muscles,and it is of great significance for the analysis of abnormal gait in patients with hemiplegia.