Training with an upper-limb prosthetic simulator to enhance transfer of skill across limbs

Objective: To examine what effect bilateral transfer of movement across limbs may have in a person's ability to learn use of an upper-limb prosthetic simulator. Design: Randomized trial. Setting: University laboratory. Participants: Able-bodied subjects randomly assigned to 1 of 3 groups. Interventions: Subjects performed 3 different tasks that required manipulation of objects with the simulator. Group 1 practiced with the simulator on the preferred limb and then transferred it to the nonpreferred limb; group 2 practiced with the simulator on the nonpreferred limb and then transferred it to the preferred limb; group 3 was a control group. Groups 1 and 2 underwent pretest trials, acquisition practice, posttest trials, and a 24-hour retention test; the control group followed the same design with the exception of acquisition practice. Main Outcome Measures: Elapsed time (1) from a signal to move until movement began (initiation time) and (2) from the beginning of movement to task completion (movement time). Results: Compared with the controls, groups 1 and 2 significantly reduced initiation time across all tasks from pretest to postlest (P=.003) and from pretest to retention test (P=.029). Groups 1 and 2 did not differ from each other. Movement time did not differ among the groups in the posttest. However, groups 1 and 2 significantly (P=.026) reduced movement time across all tasks from pretest to retention test compared with the control group. Groups 1 and 2 did not differ from each other. Conclusion: The effects of bilateral transfer were evident for initiation time immediately on transfer, and this learning effect persisted to the retention test. The ability to execute movement, represented by movement time, occurred after consolidation of learning was complete. Cross-limb training with a prosthetic simulator may be useful for persons with recent unilateral upper-extremity amputation who are learning to use a prosthesis.