As a control for effectiveness of avatar on motor behavior, 10 healthy subjects walked on a treadmill surrounded by a panoramic screen with immersive virtual reality. Eighteen post-stroke patients performed a rehabilitation with the same hardware conditions. We created a virtual “self” for the subjects and made them watch their own real-time and potentially mismatching avatar with modified knee flexion. Kinematic data were collected with 10 infrared cameras and processed with the Plug-in-Gait model. One-way Anova-s were performed to compare independent groups.
Healthy subjects knee flexion was significantly increased when avatar's one was increased by 35 degrees. Patients with increased avatar improved significantly their knee flexion by 5.35 degrees.
Using increased avatar allows to interfere with the action-perception loop, and make healthy and affected subjects bend their knee more than usual. We expect mirror neuron system to be involved in this spontaneous imitation mechanism. Experimentation dedicated to brain afferents is considered using an electroencephalogram to determine an optimum angle with stroke patients to generalize use of enhanced feedback during rehabilitation.