US Patent 7367958 Method of using powered orthotic device

A method of providing rehabilitation movement training for a person suffering from nerve damage, stroke, spinal cord injury, neurological trauma or neuromuscular disorder in attempting to move a body part about a joint using a powered orthotic device includes sensing at least one electromyographic signal of a muscle associated with motion about the joint, applying in a first direction with respect to the joint a force having a magnitude that is a first function of the at least one sensed electromyographic signal, and applying in a second direction with respect to the joint a return force that is a second function of the at least one sensed electromyographic signal, wherein the second function differs from the first function.