Effect of asymmetrical limb loading on early postural adjustments associated with gait initiation in young healthy adults

The aim of this work was to show how postural adjustments are modified in healthy subjects when gait initiation is made more difficult by an increase of the supported body weight under the starting limb. We show that the impulse due to the push of the foot against the ground is enhanced by an increase of the amplitude and duration of the initial vertical force variation. The corresponding lateral excursion of the global center of pressure (CPg) is determined mainly by this force variation, but also by lateral displacements of the centers of pressure under each foot. Rehabilitation methods of patients with gait initiation difficulties may be improved by taking into account the importance of even loading, and of the transient initial push of the starting foot.