Motor imagery practice for improving sit to stand and reaching to grasp in individuals with poststroke hemiparesis

Background: Motor imagery practice refers to the mental rehearsal of motor acts in the absence of actual movement production. Purpose: To evaluate the effect of motor imagery practice on the performance of sit to stand (STS) and reaching to grasp in subjects with post stroke chronic hemiparesis. Method: The study was designed as a crossover intervention. Participants were 13 individuals (mean age, 68.9 [±4.9] years) with chronic hemiparesis enrolled in a day center at the Bet-Rivka Rehabilitation Hospital in Petach Tikvah, Israel. Following 1 week of baseline measurements of the performance of STS and reaching to grasp, these functions were mentally practiced for 15 minutes 3 times a week for 4 weeks. Half of the subjects mentally practiced STS, while the other half practiced the reaching imagery protocol. Subsequently, the participants in each group crossed over to practice the second function for the next 4 weeks. All practice sessions were performed according to a pre-established protocol under supervision. Measurements of real performance took place twice before and twice immediately following each practice session. For STS, the Tetrax Balance System was used to measure the speed of performance and weight distribution between the legs. Reaching to grasp was appraised via a "kinematic" glove and included speed variables of the hand. Results: A significant decrease was found in the values of STS duration. Weight distribution between the legs was not affected by the intervention. For reaching to grasp, a significant improvement was found in the mean and the maximum reaching velocity. Conclusions: In individuals with chronic hemiparesis, the imagery practice of meaningful motor tasks can positively affect real performance.