Transfer of motor skill learning from the healthy hand to the paretic hand in stroke patients: a randomized...

Bilateral transfer of a motor skill is a phenomenon based on the observation that the performance of a skill with one hand can "teach" the same skill to the other hand.

In this study the ability of bilateral transfer to facilitate the motor skill of the paretic hand in patients that suffered a stroke was tested.

In a randomized controlled trial subjects were randomly assigned to either the test group or the control group.

The experiment was performed in a general hospital rehabilitation facility for inpatients and outpatients.

We studied 20 outpatients, who had their first stroke episode characterized by a brain lesion to a single hemisphere, at the end of their rehabilitation treatment. The criteria used for the selection were based on a physical examination, the time elapsed from the stroke and cognitive requirements.

The experiment consisted in training the healthy hand of each patient from the test group to execute the nine hole peg test 10 times a day, for three consecutive days, and then test the paretic hand with the same test and with bimanual tasks. The control group was not trained but went through the same analysis.

The homogeneity of the two groups has been proven. In the test group we found that the execution speed of the nine hole peg test with the paretic hand, after training the healthy hand, was on average 22.6% faster than the value recorded at baseline. The training had a positive effect on the execution of bimanual tasks. Meanwhile, no significant difference was found in the control group.

This is the first evidence that bilateral transfer of motor skills is present in patients that suffered a stroke, and that it improves the ability of the affected hand.

This observation could open the way to the development of a new approach for the rehabilitation of stroke patients.