A battery-powered, pre-programmed, lower-limb orthosis system intended to enable a patient with a walking disability resulting from spinal cord injury to perform routine ambulatory functions (e.g., stand, walk, ascend and descend stairs); it may also be used to help promote intrinsic motor function. It is typically strapped to the patient over clothing and includes an exoskeleton structure made of metal, with electric motors, mechanical actuators and sensors, an on-board computer, and controls. It is intended for single-patient use, typically outside of a controlled setting following completion of training under professional supervision.