Biomechanical mechanisms and centre of pressure trajectory during planned gait termination

Although gait initiation has been extensively studied, gait termination has received less attention. In particular, the trajectory of the centre of pressure (CoP) during gait termination, as well as the trajectory's determinants, has not yet been described. The purpose of the present study was to characterize the kinetic components of planned gait termination (including the CoP trajectory) with respect to the various gait events and centre of mass speed and trajectory.

Thirty healthy subjects were asked to walk along a test track and stop on a force platform while an optoelectronic system recorded temporal and spatial parameters. A total of 90 trials were analysed.

Subjects needed two steps to stop on the force platform. The CoP trajectory during gait termination was composed of three phases. During the first phase, the CoP moved forward under the stance foot, which was in contact with the ground. The ground reaction forces exerted a sagittal braking action. The second phase showed a lateral CoP shift and was correlated with braking; this may correspond to anticipatory postural adjustments for gait termination. The third and last phase might correspond to compensatory adjustments before the stance phase.

CoP trajectory is more complex during gait termination than during gait initiation. Gait termination comprises several specific sequences in the gait-stance transition. A better understanding of the kinetic parameters in gait termination should enable us to identify which kinetic parameters could be considered as risk factors for falls.