Reaching kinematics to measure motor changes after mental practice in stroke

Objective: To examine mental practice (MP) efficacy using a new kinematics reaching model. Method: This was a pre-post, case series conducted at an outpatient rehabilitation hospital of 5 patients who experienced stroke >1 year before study entry (3 males; mean age = 52.6 ± 15.4 years [range, 38-76 years]; mean time since stroke = 51.2 months [range, 13-126 months]) exhibiting upper limb hemiparesis on their dominant sides. Participants received 30-minute therapy sessions emphasizing activities of daily living (ADLs) using their affected arms, which occurred 2 days/week for 6 weeks. After therapy, participants received 30-minute MP sessions requiring MP of the ADLs. The main outcome measure was 3-D Motion Analysis (kinematics), in which patients performed 2 functional reaching tasks consisting of reaching and grasping a plastic cylinder positioned at either elbow height (reach out) or shoulder height (reach up). Dependent variables included horizontal reaching distance, hand velocity, elbow range of motion, and shoulder range of motion. Results: Prior to intervention, the mean horizontal reaching distance was 8.3 ± 1.7 cm and 10.9 ± 2.2 cm for the reach-up and reach-out tasks, respectively. Upon completion of the intervention, ability to reach up significantly improved to 9.9 ± 1.6 cm (p < .001). Horizontal reach distance also improved during the reach-out task (11.7 ± 2.2 cm, p = .366). No statistically significant change was observed in linear hand velocity. Patients also exhibited greater shoulder flexion and elbow extension during both the posttest reach-up and posttest reach-out tasks. Discussion and Conclusion: Kinematics appears to offer a precise, objective way of quantifying MP-induced motor changes during ADL performance. MP appears to improve several aspects of affected arm reaching.