Characteristics of the Gait Induced by a Fall

Abstract

The performance of a voluntary movement brings into play anticipatory postural adjustment processes (Belenkii et al., 1967; Bouisset and Zattara, 1981) which contribute to the general dynamic organization of balance and serve to reduce postural disturbances due to the forthcoming movement. A similar anticipatory postural adjustment has been described in spontaneous initiation of gait (Breniere and Do, 1985). Initiation of gait has been defined as the transient phase elapsed between the initial postural phase and the stationary gait. It is composed of an anticipatory adjustment phase and a step execution phase. The anticipatory adjustment phase aims to free the stepping foot and to create the necessary conditions to obtain a stationary forward progression, i.e. to create the propulsive forces. It has been shown that in spontaneous initiation of gait, time elapsed between onset of movement and onset of oscillatory phase increased with respect to the speed of progression, whereas the duration of the oscillatory phase decreased. However, the sum of the two times was constant whatever the speed of progression (Breniere and Do, in press). It was suggested that the speed of progression was the relevant parameter to build up the motor program.