Locomotor adaptations following repeated waist-pull perturbations

Falls are acknowledged as one of the most serious problems in the elderly. In order to develop effective interventions to reduce the fall risk, perturbation-based training programs are being adopted. The exposure to repeated unexpected perturbations can modify proactive strategies to control dynamical gait stability and decrease the risk of falling during unpreventable events encountered in everyday life. The aim of this study was to analyze to what extent healthy adult gait patterns would be affected by exposure to repeated unexpected force-controlled antero-posterior waist-pull perturbations. Results showed that repeated waist-pull perturbations produced short-term after effects able to modify stability in the direction of the applied perturbations. In particular, subjects increased their step length, the oscillation of the extrapolated center of mass along the antero-posterior and vertical direction, the antero-posterior Margin of Stability and the range of angular momentum in the sagittal plane. Future experiments will be conducted to verify if the present results can be confirmed with elderly subjects in order to finally improve their dynamical stability during unperturbed walking.