Background. Upper limb robot-assisted therapy (RT) provides intensive, repetitive, and task-specific treatment, and its efficacy for stroke survivors is well established in literature. Biomechanical data from robotic devices has been widely employed for patient’s assessment, but rarely it has been analysed for tracking patient progress during RT. The goal of this retrospective study is to analyse built-in kinematic data registered by a planar end-effector robot for assessing the time course of motor recovery and patient’s workspace exploration skills. A comparison of subjects having mild and severe motor impairment has been also conducted. For that purpose, kinematic data recorded by a planar end-effector robot have been processed for investigating how motor performance in executing point-to-point trajectories with different directions changes during RT. Methods. Observational retrospective study of 68 subacute stroke patients who conducted 20 daily sessions of upper limb RT with the InMotion 2.0 (Bionik Laboratories, USA): planar point-to-point reaching tasks with an “assist as needed” strategy. The following kinematic parameters (KPs) were computed for each subject and for each point-to-point trajectory executed during RT: movement accuracy, movement speed, number of peak speed, and task completion time. The Wilcoxon signed-rank tests were used with clinical outcomes. the Friedman test and post hoc Conover’s test (Bonferroni’s correction) were applied to KPs. A secondary data analysis has been conducted by comparing patients having different severities of motor impairment. The level of significance was set at value < 0.05. Results. At the RT onset, the movements were less accurate and smoothed, and showed higher times of execution than those executed at the end of treatment. The analysis of the time course of KPs highlighted that RT seems to improve the motor function mainly in the first sessions of treatment: most KPs show significant intersession differences during the first 5/10 sessions. Afterwards, no further significant variations occurred. The ability to perform movements away from the body and from the hemiparetic side remains more challenging. The results obtained from the data stratification show significant differences between subjects with mild and severe motor impairment. Conclusion. Significant improvements in motor performance were registered during the time course of upper limb RT in subacute stroke patients. The outcomes depend on movement direction and motor impairment and pave the way to optimize healthcare resources and to design patient-tailored rehabilitative protocols.

中文翻译：

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上肢机器人辅助康复期间跟踪患者进展的运动学参数：对亚急性中风受试者的观察性研究。

背景。上肢机器人辅助治疗（RT）提供强化、重复和针对特定任务的治疗，其对中风幸存者的疗效已在文献中得到充分证实。来自机器人设备的生物力学数据已广泛用于患者评估，但很少被分析用于跟踪 RT 期间患者的进展。这项回顾性研究的目的是分析平面末端执行器机器人记录的内置运动学数据，以评估运动恢复的时间过程和患者的工作空间探索技能。还对患有轻度和重度运动障碍的受试者进行了比较。为此，对平面末端执行器机器人记录的运动学数据进行了处理，以研究在 RT 期间执行不同方向的点对点轨迹时的电机性能如何变化。方法。对 68 名亚急性中风患者进行的观察性回顾性研究，他们使用 InMotion 2.0（美国 Bionik 实验室）每天进行 20 次上肢 RT：采用“按需协助”策略执行平面点对点到达任务。为每个受试者和 RT 期间执行的每个点对点轨迹计算以下运动学参数 (KP)：运动精度、运动速度、峰值速度数和任务完成时间。Wilcoxon 符号秩检验用于临床结果。Friedman 检验和事后 Conover 检验（Bonferroni 修正）适用于 KP。通过比较具有不同运动障碍严重程度的患者进行了二次数据分析。显着性水平设置为值 < 0.05。结果。在 RT 开始时，动作不太准确和平滑，并且比治疗结束时执行的动作显示出更高的执行次数。对 KP 时程的分析强调，RT 似乎主要在治疗的第一个疗程中改善运动功能：大多数 KP 在前 5/10 疗程中显示出显着的疗程间差异。此后，没有发生进一步的重大变化。执行远离身体和偏瘫一侧的运动的能力仍然更具挑战性。从数据分层获得的结果显示，轻度和重度运动障碍受试者之间存在显着差异。结论。亚急性卒中患者在上肢放疗期间运动表现显着改善。结果取决于运动方向和运动障碍，并为优化医疗资源和设计针对患者的康复方案铺平道路。