Typical upper limb-mediated activities of daily living involve coordination of both arms, often requiring distributed contributions to mechanically coupled tasks, such as stabilizing a loaf of bread with one hand while slicing with the other. We sought to examine whether mild paresis in one arm results in deficits in performance on a bilateral mechanically coupled task. We designed a virtual reality-based task requiring one hand to stabilize against a spring load that varies with displacement of the other arm. We recruited 15 chronic stroke survivors with mild hemiparesis and 7 age-matched neurologically intact adults. We found that stroke survivors produced less linear reaching movements and larger initial direction errors compared to controls (p < 0.05), and that contralesional hand performance was less linear than that of ipsilesional hand. We found a hand × group interaction (p < 0.05) for peak acceleration of the stabilizing hand, such that the dominant right hand of controls stabilized less effectively than the nondominant left hand while stroke survivors showed no differences between the hands. Our results indicate that chronic stroke survivors with mild hemiparesis show significant deficits in reaching aspects of bilateral coordination, but no deficits in stabilizing against a movement-dependent spring load in this task.

中文翻译：

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轻度单侧麻痹的慢性中风幸存者机械耦合不对称双侧任务的表现缺陷


典型的上肢介导的日常生活活动涉及双臂的协调，通常需要对机械耦合任务进行分布式贡献，例如用一只手稳定一条面包，同时用另一只手切片。我们试图检查一只手臂的轻度麻痹是否会导致双侧机械耦合任务的表现缺陷。我们设计了一个基于虚拟现实的任务，需要一只手稳定弹簧负载，而弹簧负载随着另一只手臂的位移而变化。我们招募了 15 名患有轻度偏瘫的慢性中风幸存者和 7 名年龄匹配的神经系统完好的成年人。我们发现，与对照组相比，中风幸存者产生的线性伸手运动较少，初始方向误差较大（ p < 0.05），并且对侧手的表现不如同侧手的线性。我们发现稳定手的峰值加速度存在手×组交互作用（ p < 0.05），因此控制中的主导右手的稳定效果不如非主导左手，而中风幸存者的双手之间没有差异。我们的结果表明，患有轻度偏瘫的慢性中风幸存者在达到双侧协调方面表现出明显的缺陷，但在这项任务中稳定运动依赖的弹簧负载方面没有缺陷。