Asymmetry of gait initiation in hemiparetic stroke subjects

Abstract

Objective: To investigate symmetry of gait initiation in healthy and hemiparetic subjects. Design: Survey Setting: Kinematic laboratory affiliated with a hospital-based department of rehabilitation Patients or Other Participants: Ten healthy and 14 hemiparetic stroke subjects starting five times with their right and left leg, respectively. Main Outcome Measures: Duration of defined periods, step length, center of pressure, and center of mass were recorded and calculated using two triaxial force plates, contact switches, and a video camera system. Results: Healthy subjects displayed a high degree of independence of kinetic and kinematic parameters of the starting limb. Hemiparetic patients showed differences with respect to the starting limb: when starting with the nonaffected leg, the swing period and step length was shorter and the center of pressure displayed a more marked medio-lateral sway with no corresponding initial movement of the center of mass; when starting with the affected leg the movement pattern of the center of pressure and center of mass was comparable to that of normal subjects. Conclusions: The trajectories of the center of pressure and center of mass and the symmetry parameters are in accordance with a higher degree of uncertainty when starting with the non-affected limb in hemiparetic subjects.