Abstract
Ankle dorsiflexion function during swing phase of the gait cycle contributes to foot clearance and plays an important role in walking ability post-stroke. Commonly used biomechanical measures such as foot clearance and ankle joint excursion have limited ability to accurately evaluate dorsiflexor function in stroke gait. We retrospectively evaluated ankle angular velocity and ankle angular acceleration as direct measures for swing phase dorsiflexor function in post-stroke gait of 61 chronic stroke survivors. Our linear regression models revealed that peak ankle angular velocity (AAVP), peak ankle angular acceleration (AAAP), peak dorsiflexion angle (DFAP) and peak foot clearance (FCLP) during swing had a significant relationship (p < 0.05) with impaired dorsiflexion function. AAAP and DFAP accounted for the most variance of dorsiflexion function. Additionally, AAVP, AAAP, FCLP during swing, correlated significantly with all clinical outcome measures of walking ability. DFAP during swing had a positive correlation only with FMA-LE. Post-hoc William’s t-tests, used to compare the magnitude of difference between two non-independent correlations, revealed that the correlation between all clinical measures and DFAP were significantly weaker than with AAVP and AAAP. We also found that correlation between FMA-LE and FCLP was weaker than with AAVP and AAAP. We found an excellent test-retest reliability for both AAVP (ICC = 0.968) and AAAP (ICC = 0.947). These results suggest that DFAP may only be associated with non-task specific isolated dorsiflexion movement, but not during walking. FCLP is associated with dorsiflexion function and walking ability measures but not as strongly as AAVP and AAAP possibly because FCLP is influenced by contribution from hip and knee joint movements during walking. Therefore, we believe that AAVP and AAAP both can be used as reliable measures of impaired dorsiflexion function in post-stroke gait.
Competing Interest Statement
The authors have declared no competing interest.