Quantification of functional weakness and abnormal synergy patterns in the lower limb of individuals with chronic stroke
Quantification of functional weakness and abnormal synergy patterns in the lower limb of individuals with chronic stroke
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DOI：
10.1186/1743-0003-3-17
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发表时间：
2006-07-20
影响因子：
5.1
通讯作者：
Hidler, Joseph
中科院分区：
文献类型：
--
作者：
Neckel, Nathan;Pelliccio, Marlena;Hidler, Joseph
背景：异常肌肉激活模式的存在是限制卒中后患者运动康复的一个有充分证据的因素。这些异常的肌肉激活模式，或协同效应，以前在上肢中已经被量化。本文介绍了16例慢性偏瘫中风患者和16名年龄匹配的对照组在站立姿势下的下肢关节扭矩模式，以检验两组之间力量和协调性的差异。方法：在躯干稳定的情况下，中风患者用未患病的腿站立，而他们的患脚连接到一个6自由度测力仪(JR3，Woodland CA)上，该传感器记录力和扭矩。受试者被要求产生关于给定关节的最大扭矩(髋关节外展/内收；髋关节、膝盖和踝关节屈曲/伸展)，并提供他们对该主要关节轴产生的扭矩的反馈。同时，记录8个肌群的肌电数据，并计算相邻关节产生的二次力矩。使用单因素方差分析比较平均一次扭矩、二次扭矩和肌电数据的差异。结果：中风组在测试的八个方向中有六个方向明显较弱。对次级扭矩的分析表明，控制组和中风受试者在测试的八个关节动作中有七个使用了类似的策略来产生最大扭矩。唯一一次使用不同的策略是在最大的髋关节外展运动期间，中风患者倾向于屈曲而不是伸展髋关节，这与经典定义的“屈曲协同作用”是一致的。中风组的肌电数据与对照组不同，因为存在强烈的对抗性肌肉群的共同收缩，特别是在踝关节屈曲和踝关节和膝关节伸展期间。结论：本研究的结果表明，与年龄匹配的对照组相比，站立姿势中风患者的患侧腿部明显弱于年龄匹配的对照组，但几乎没有证据表明经典的下肢异常协同模式。这一发现表明，慢性中风患者的等长性肢体运动障碍的主要原因是虚弱。
Background: The presence of abnormal muscle activation patterns is a well documented factor limiting the motor rehabilitation of patients following stroke. These abnormal muscle activation patterns, or synergies, have previously been quantified in the upper limbs. Presented here are the lower limb joint torque patterns measured in a standing position of sixteen chronic hemiparetic stroke subjects and sixteen age matched controls used to examine differences in strength and coordination between the two groups.Methods: With the trunk stabilized, stroke subjects stood on their unaffected leg while their affected foot was attached to a 6-degree of freedom load cell (JR3, Woodland CA) which recorded forces and torques. The subjects were asked to generate a maximum torque about a given joint (hip abduction/adduction; hip, knee, and ankle flexion/extension) and provided feedback of the torque they generated for that primary joint axis. In parallel, EMG data from eight muscle groups were recorded, and secondary torques generated about the adjacent joints were calculated. Differences in mean primary torque, secondary torque, and EMG data were compared using a single factor ANOVA.Results: The stroke group was significantly weaker in six of the eight directions tested. Analysis of the secondary torques showed that the control and stroke subjects used similar strategies to generate maximum torques during seven of the eight joint movements tested. The only time a different strategy was used was during maximal hip abduction exertions where stroke subjects tended to flex instead of extend their hip, which was consistent with the classically defined "flexion synergy."The EMG data of the stroke group was different than the control group in that there was a strong presence of co-contraction of antagonistic muscle groups, especially during ankle flexion and ankle and knee extension.Conclusion: The results of this study indicate that in a standing position stroke subjects are significantly weaker in their affected leg when compared to age-matched controls, yet showed little evidence of the classic lower-limb abnormal synergy patterns previously reported. The findings here suggest that the primary contributor to isometric lower limb motor deficits in chronic stroke subjects is weakness.