Deficits in motor coordination of the paretic lower limb best explained activity limitations after stroke

Objective: To explore the relationships between selected measures of motor impairments and activities involving the lower-limbs in ambulatory people with chronic stroke. Design: Motor impairment measures included maximal isometric strength and motor coordination. Activity measures included walking speed, stair ascent/descent cadences, and the time to perform the Timed Up and Go (TUG) test. Results: Ninety individuals were included. The correlations between all motor impairment and activity measures were significant (0.18 < r < 0.52, p < 0.05). Motor coordination and strength of the knee flexor muscles explained 30% (F = 20.3; p < 0.001) of the variance in walking speed, 32% (F = 19.1; p < 0.001) of stair ascent, and 31% (F = 16.8; p < 0.001) of stair descent cadence. Regarding the TUG, only motor coordination reached significance and explained 13% (F = 13.4; p < 0.001) of the variance. Conclusion: Measures of strength and motor coordination of the paretic lower limb were significantly correlated with all activity measures. However, despite the fact that knee flexor strength explained some variance in walking speed and stair ascent/descent cadences, motor coordination was the only measure that explained the variances in all three selected activity measures. These findings are innovative for neurological rehabilitation, since this is the first study to demonstrate that deficits in motor coordination of the paretic lower limb best explained limitations in performing different lower-limb activities.