Saturated muscle activation contributes to compensatory reaching strategies after stroke
Saturated muscle activation contributes to compensatory reaching strategies after stroke
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DOI：
10.1152/jn.00732.2004
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发表时间：
2005-11-01
影响因子：
2.5
通讯作者：
Hodgson, AJ
中科院分区：
文献类型：
--
作者：
McCrea, PH;Eng, JJ;Hodgson, AJ
如果肌肉不能产生足够的力量，中风引起的虚弱可能会改变运动的控制和执行。本研究的目的是确定20名慢性中风患者和10名年龄匹配的健康对照者在正向（矢状）到达任务中的代偿策略。我们假设，在到达任务期间，paretic前三角肌将被最大限度地激活（即饱和），并且任务完成将需要激活额外的肌肉，从而导致矢状面外的代偿运动。对于控制对象的伸手运动，关节运动主要保持在矢状面，手的运动轨迹平滑直接。中风受试者非麻痹臂的运动特征与对照组相似，只是外展角和前三角肌激活的百分比略有增加。相比之下，中风患者的麻痹臂伸展运动的特点是所有肌肉的激活增加，尤其是外侧三角肌，除了前三角肌，导致肩部外展力和分节和间接的手部运动。对于中风患者的瘫臂，肌肉和动力补偿随着损伤严重程度的增加而增加，较弱的肌肉在可用肌肉活动中所占的比例更高。这些结果表明，在向前伸展任务中，典型激动剂无法产生足够的力量，可能需要代偿性肌肉招募策略来完成任务。
The control and execution of movement could potentially be altered by the presence of stroke-induced weakness if muscles are incapable of generating sufficient power. The purpose of this study was to identify compensatory strategies during a forward ( sagittal) reaching task for 20 persons with chronic stroke and 10 healthy age-matched controls. We hypothesized that the paretic anterior deltoid would be maximally activated (i.e., saturated) during a reaching task and that task completion would require activation of additional muscles, resulting in compensatory movements out of the sagittal plane. For reaching movements by control subjects, joint motion remained largely in the sagittal plane and hand trajectories were smooth and direct. Movement characteristics of the nonparetic arm of stroke subjects were similar to control subjects except for small increases in the abduction angle and the percentage that anterior deltoid was activated. In contrast, reaching movements of the paretic arm of stroke subjects were characterized by increased activation of all muscles, especially the lateral deltoid, in addition to the anterior deltoid, with resulting shoulder abduction power and segmented and indirect hand motion. For the paretic arm of stroke subjects, muscle and kinetic compensations increased with impairment severity and weaker muscles were used at a higher percentage of their available muscle activity. These results suggest that the inability to generate sufficient force with the typical agonists involved during a forward reaching task may necessitate compensatory muscle recruitment strategies to complete the task.