Improving the Standing Balance of People with Spinal Cord Injury Through the Use of a Powered Ankle-Foot Orthosis

In this study, our goal was to improve the standing balance of people with a Spinal Cord Injury (SCI) by using a powered Ankle-Foot orthosis acting in the sagittal plane. We tested four different controllers on two SCI subjects that have a lesion at a low level. In the experiments the subjects repeatedly had to recover from pelvis perturbations, while receiving ankle assistive torques from the orthosis. We found that the controllers that use centroidal dynamics as input parameters were able to provide proper support to the subjects after a perturbation had been applied, even though they worked against the subjects after they had recovered from the perturbation. These preliminary results show the potential of balancing controllers that operate in Center of Mass-space.