Intermanual transfer effect in young children after training in a complex skill: mechanistic, pseudorandomized, pretest-posttest study.

BACKGROUND Intermanual transfer implies that motor skills learned on one side of the body transfer to the untrained side. This effect was previously noted in adults practicing with a prosthesis simulator. OBJECTIVE The study objective was to determine whether intermanual transfer is present in children practicing prosthetic handling. DESIGN A mechanistic, pseudorandomized, pretest-posttest design was used. SETTING The study was conducted in a primary school in the Netherlands. PARTICIPANTS The participants were children who were able-bodied (N=48; 25 boys, 23 girls; mean age=5.1 years) and randomly assigned to an experimental group or a control group. INTERVENTION The experimental group performed 5 training sessions using a prosthesis simulator on the training arm. Before (pretest), immediately after (posttest), and 6 days after (retention test) the training program, their ability to handle the prosthesis with the contralateral (test) arm was measured. The control group only performed the tests. Half of the children performed the tests with the dominant hand, and the other half performed the tests with the nondominant hand. MEASUREMENTS During the tests, movement time and control of force were measured. RESULTS An interaction effect of group by test was found for movement time. Post hoc tests revealed significant improvement in the experimental group between the posttest and the retention test. No force control effect was found. LIMITATIONS Only children who were able-bodied were included. Measurements should have been masked and obtained without tester interference. The fact that 4 children whose results were slower than the mean result discontinued training may have biased the findings. CONCLUSIONS The intermanual transfer effect was present in 5-year-old children undergoing training in prosthetic handling. After training of one hand, children's movement times for the other, untrained hand improved. This finding may be helpful for training children who are novice users of a prosthesis.