The invention relates to embodiments of methods for extending a subject-controllable range of joint motion, and for increasing subject control of joint movement within a range of motion. Embodiments include fastening a powered device around a joint so as to be able to control the joint, allowing the subject to move the joint within a range of volitional motion, and then engaging the powered device to support movement of the joint into an expanded, rehabilitative range. In some embodiments, the device supports joint movement by substantially providing the force to move the joint beyond the volitional boundary. In other embodiments, supporting movement includes the subject substantially providing the force, and the device allowing movement only in a desired direction. The invention further relates to a system for increasing the functional capability of a joint by implementing embodiments of the method. By such methods and system, rehabilitation is accomplished both by building strength, and training neural pathways.