Effects of Single-handed and Dual-handed Tasks on Myoelectric Hand Prosthesis Operability of Unilateral Transradial Amputees

Objective: The influence of myoelectric hand training on the ability of amputees to operate a prosthetic hand has not been fully verified. This study aimed to investigate the effects of single-handed and dual-handed tasks on the ability of amputees to use a myoelectric prosthetic hand in training. Method: The subjects were unilateral transradial amputees (n = 12). The training effects of each task were measured by assigning the myoelectric hand prosthesis users to two groups and conducting a crossover study: one group performed the single-handed task first followed by the dual-handed task, and the other group did the opposite. The Southampton Hand Assessment Procedure (SHAP) score was used to assess the subjects' ability to control the myoelectric prosthetic hand.Results: The training effect differed significantly between the single-handed task, SHAP score: 6.3 (5.8-8.5) points, and the dual-handed task, SHAP score: 10.3 (8.8-14.2) points; however, the effect was insufficient (p = 0.008, r = 0.20).Conclusion: The dual-handed task improved the subjects' ability to accurately operate a myoelectric hand more effectively than the single-handed task. This suggests that the dual-handed task is more effective at developing control of opening/closing movements and object handling with a myoelectric hand than the single-handed task.