Augmented feedback for the lower-limb amputees : can a rhythmic stimulation desynchronise the gait of healthy subjects ?

Part of the research on augmented feedback for lower limb amputees, this thesis proposed a new gait perturbation experiment, attempting to desynchronise the gait of healthy subjects using a rhythmic stimulation. The hypothesis is the following: if such stimulation can desynchronise the gait of healthy subjects, it could be used to re-synchronise the gait of lower limb amputees. Indeed, lower limb amputees are experiencing an asymmetrical gait, which can lead to complications such as an increased falling rate, or pathologies like osteoarthritis. Hence, improving their gait symmetry is key to enhance their quality of life. Five healthy subjects participated to the three 6-minute treadmill walking experiments, while rhythmic auditory cues were sent alternately in the left and right ears. Subjects were asked to synchronise their feet to the ipsilateral stimuli. The different experimental conditions consisted in a control experiment, with isochronous stimuli delivery, and two perturbation experiments, where different phase shifts were progressively applied to the stimuli delivery. To assess the effects of the stimulation, the time between two subsequent steps was measured. The results show that the delays induced had no significant effects on gait symmetry. Interestingly though, retention effects have been found after the exposition to the stimulation: gait symmetry is increasing.