Gait reveals bilateral adaptation of motor control in patients with chronic unilateral stroke

BACKGROUND AND AIMS: Functional brain imaging has shown that bilateral brain reorganization may occur after unilateral cerebral damage. The present study searched for evidence of bilateral motor control changes in gait in patients with chronic unilateral stroke. METHODS: Gait variables (temporal and spatial parameters, footprint peak times (FPPT) and footfall times (FFT)) were recorded in 48 patients with chronic unilateral stroke at their preferred speed, and in 10 healthy volunteers walking from very slowly to very fast on a pressure sensor walkway. The data were divided into 4 groups according to gait velocity. The functional outcome of stroke was measured by the Barthel Index. RESULTS: Patients' gait variables reflected their hemiparetic gait pattern. Slower patients had prolonged stance, FPPT and FFT on the non-affected side (NS), and prolonged swing and shorter FPPT and FFT on the affected side (AS). The magnitude of the asymmetry index of these parameters was inversely associated with velocity performance and, at the same time, it characterized how much the control of the clinically healthy (NS) side was altered during walking. Bilateral changes in kinetic and footfall variables in the chronic stage of unilateral stroke were present. CONCLUSIONS: Patients chose their preferred walking velocity using stereotyped, alternative gait patterns, in which the contribution of the NS was larger than that of the AS. Alternative gait patterns may partly demonstrate compensatory behavioral strategies adapted by patients.