Side-Specific Movement Strategies During Maximal Arm Elevation in Individuals With Stroke: A Cross-Sectional Study

Objectives Compensatory movements of the paretic upper limb are commonly observed after stroke. Previous studies have mainly investigated tasks performed below shoulder height, such as reaching movements. However, activities of daily living also require arm elevation close to maximal range, which may impose greater mechanical demands and induce different compensatory strategies. This study aimed to determine differences in joint kinematics between paretic and nonparetic arm elevation at different points of the movement. Methods In this prospective cross-sectional study, 11 individuals with subacute hemiplegic stroke performed maximal forward elevation of the paretic and nonparetic upper limbs while seated in a standardized posture. Three-dimensional motion capture was used to analyze joint kinematics of the head, trunk, shoulder, and elbow. Joint angles were extracted at three points of the movement based on the percentage of maximal upper-arm segment flexion: early (10%), middle (50%), and peak (100%). Differences between paretic and nonparetic limb elevation were analyzed. Results During the early and middle points, no significant differences were observed in the compensatory kinematic variables other than the flexion angles used to characterize movement progression. However, at maximal elevation, elbow flexion was significantly greater during paretic limb elevation than during nonparetic limb elevation. In contrast, shoulder internal rotation was smaller during paretic limb elevation, and shoulder abduction did not differ significantly between conditions. Conclusions During maximal arm elevation, increased elbow flexion was one of the prominent kinematic differences observed between the paretic and nonparetic upper limbs, whereas excessive shoulder internal rotation was not observed. These findings highlight the importance of considering elbow flexion, in addition to shoulder rotation, when evaluating upper-limb movement in individuals with stroke.