Trunk stabilization by feedback sway control in FES-induced paraplegic standing

The feasibility of trunk stabilization was demonstrated during the standing of an individual with paraplegia by using functional electrical stimulation (FES). A control system was designed for the feedback control of the sagittal and the coronal trunk inclination angles. The system was constructed of two proportional-and-derivative (PD) controllers and a three-dimensional co-activation stimulation map. The clinical evaluation of the effect in disturbance suppression was performed by applying a step disturbance, in an individual with spinal cord injury at the thoracic eighth level. The pelvis and the lower extremities were fixed by using parallel bars and knee-ankle-foot-orthosis. The decrease of the backward sway magnitude by using the proposed system was confirmed