Abstract
It is of importance to understand not only motor control during steady-state gait, but also that at the initiation of gait. Healthy people initiate gait by activating anterior tibial muscle followed by inactivation of triceps muscle of the calf. Functions of these muscles induce a posterior shift of the center of foot pressure, and a body is rotated forward by gravity, thereby initiating the anterior movement of the center of gravity. Although this basic process is uniform regardless of age, the posterior locomotion of the center of foot pressure tends to be small in children or the elderly. The period from gait initiation to the end of the first step depends on biomechanical conditions, not on gait velocity. Gait initiation in Parkinson’s disease is characterized by an elongation of the postural phase.
