Interlimb training improves motor function in partial-hand but not necessarily transradial simulated prosthesis use.

The development of empirical approaches for functional rehabilitation during the acute and subacute stages following upper limb amputation is needed. For persons with unilateral limb loss, interlimb training is a potentially attractive approach, as it may allow for the translation of learned function from the unaffected to affected side while awaiting prosthesis fitting. Persons with sound limbs performed simple and complex reach-to-grasp motor tasks using a body-powered transradial or partial-hand prosthesis simulator in a 5-day interlimb training paradigm. Prior work in a single-session paradigm found improvments in motor control with prosthesis simulators, with an especially strong effect in partial-hand device use. Here, we hypothesized that participating in interlimb training would result in improvements in motor control with the prostheses, particularly in partial-hand device use and during complex tasks. Overall, partial-hand prosthesis users showed greater performance adaptations with interlimb training than transradial prosthesis users, who tended to show no improvements following training in either task. We also found that partial-hand users showed significantly higher reach peak velocities compared to transradial users following training in both the simple and complex task. These results suggest that interlimb training may provide tangible benefits during early-stage rehabilitation following upper limb amputation, especially in cases of partial-hand loss.