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.