DiRocco Shawn J, Casas Rafael, Culp Seraphina A, Lum Peter S
IEEE Trans Neural Syst Rehabil Eng. 2025;33:1509-1518. doi: 10.1109/TNSRE.2025.3562527. Epub 2025 Apr 29.
The flexor synergy after stroke results in involuntary activation of distal muscles when lifting the shoulder against gravity. This contributes to impaired ability to perform activities of daily living. Robotic exoskeletons can be useful in assessing the strength of the synergy and applying therapy modes that promote improved movement patterns. In this study, we evaluated 16 chronic stroke patients using the Ultra Low Impedance eXoskelton (ULIX). The subjects performed two synergy assessment tasks, elbow extension and hand opening while holding shoulder flexion at greater than 70 degrees with various gravity support levels. Joints not part of the tasks were locked in place. During the assessment tasks, increasing gravity support resulted in more elbow extension and reduced grip force; however, EMG contraction ratios of distal muscles compared to deltoids increased when gravity support was increased. A free cup reaching task was performed using several proposed therapy modes. During the cup reaching task, the therapy modes increased range of motion and improved the shoulder-elbow kinematic coordination compared with gravity support alone. There was a strong correlation between synergy expression in the elbow extension task and performance of the cup reaching task. Isolating movement to shoulder flexion and elbow extension during the assessment task resulted in better elbow extension than in the cup reaching task where all joints were free to rotate.
中风后的屈肌协同作用会导致在抗重力抬起肩部时远端肌肉的不自主激活。这导致日常生活活动能力受损。机器人外骨骼可用于评估协同作用的强度，并应用促进改善运动模式的治疗方式。在本研究中，我们使用超低阻抗外骨骼（ULIX）对16名慢性中风患者进行了评估。受试者执行了两项协同作用评估任务，即肘部伸展和手部张开，同时在不同重力支持水平下保持肩部屈曲大于70度。未参与任务的关节被锁定在固定位置。在评估任务期间，增加重力支持会导致更多的肘部伸展和握力降低；然而，当增加重力支持时，与三角肌相比，远端肌肉的肌电图收缩比率增加。使用几种提议的治疗方式进行了自由取杯任务。在取杯任务期间，与仅重力支持相比，治疗方式增加了运动范围并改善了肩肘运动学协调性。肘部伸展任务中的协同作用表现与取杯任务的表现之间存在很强的相关性。在评估任务期间将运动隔离为肩部屈曲和肘部伸展，比在所有关节都可自由旋转的取杯任务中产生了更好的肘部伸展。
