Improved Kinematics and Motor Control in a Longitudinal Study of a Complex Therapy Movement in Chronic Stroke

Impaired motor control post-stroke is typically measured using clinical assessments employing categorical and subjective scoring. We investigated quantitative kinematic parameters of a complex movement with therapy in chronic stroke. Tri-axial accelerometry of the more-affected arm of 24 patients was recorded during early- (day 2-3) and late- (days 12-14) therapy, and for 13 patients at 6-month follow-up. Clinical assessments included the classification of motor-function as low, moderate, or high. Kinematic parameters were measured during Wii-baseball swings to assess the effect of time and the level of motor-function. Clinical tests improved over time (all p < 0.01). Increased acceleration magnitude over time was significant only at proximal sensors (p < 0.05), and there was an effect of motor-function at distal sensors (p < 0.05). Normalized velocity decreased (p < 0.05) at all sensors over time. Peak acceleration and peak deceleration increased over time, predominately at proximal sensors. Kinematic parameters provide an objective and quantitative measure of change in motor-function that is not possible with clinical assessments. The complex patterns of change were not consistent between and within levels of motor-function but reflected improved motor control that was sustained over time. These data emphasize the potential for ongoing improvements in motor capacity in chronic stroke with additional rehabilitation.