The impact of wrist flexion on task performance and compensatory movements in transradial prosthesis users

Upper-limb prosthetic technology has advanced in recent years, yet most commercially available prosthetic wrists offer only a single active degree of freedom (DOF), typically rotation, with few providing powered flexion/extension. This limitation often forces users to compensate with proximal joints, leading to unnatural movements and potential overuse injuries. Despite user demand for improved wrist movement, few powered wrist options exist, and current outcome measures rarely quantify compensatory strategies directly. To address this gap, the Gaze and Movement Assessment (GaMA) metric was used to evaluate task performance and compensatory movements in five adults with unilateral transradial limb absence, fitted with a custom 2-DOF powered wrist. Participants completed the GaMA Tasks and functional outcomes under two conditions: with and without wrist flexion/extension. Results showed that, though individual variability was high, enabling wrist flexion/extension was seen to reduce some compensatory trunk and shoulder movements towards normative data. These findings suggest that powered wrist flexion/extension may support more normative movement patterns and highlight the importance of individualized prosthetic training. Future work should focus on targeted rehabilitation strategies to minimize compensatory movements as device complexity increases.