An apparatus and method for rehabilitating a joint of a user is provided. The apparatus includes a modular frame configured to support the joint in a predefined position. A plurality of pulleys are adjustably coupled to one or more locations on the modular frame. A plurality of cords pass through the plurality of pulleys and couple to opposing ends of a boot. The boot surrounds a portion of the user distal to the joint. The plurality of cords permit a user to actuate the joint through a full range of motion. The user may selectively apply either a resistive force or an assistive force through the one or more cables to affect the joint through its range of motion.