A strategy used by paraplegics to stand up using FES

Many paraplegics can stand up if their leg extensor muscles are stimulated without feedback to the stimulator-controller. Their neurologically-intact upper bodies control the motion by exerting forces through the arms. To develop stimulator-controllers, the authors wish to understand the strategy they use. In two subjects, the authors measured the handle forces and the posture during standing up. Plotted so as to relate the handle forces to the leg joints, the results show that the upper body helps extend the knees and then the hips: a strategy the authors call quick knee-locking. This may keep the upper body forces within the limits of its strength.