An orthotic system includes a controller, a joint and a fail-safe system for the joint. In a preferred embodiment, the orthotic system is an exoskeleton, the joint is a knee joint and the fail-safe system is a normally engaged brake that is controlled by the controller. The brake is engaged when the controller fails or the exoskeleton is powered off. The exoskeleton also includes an electrical or mechanical brake disengagement mechanism, separate from the controller, so that an exoskeleton user can disengage the brake when desired. The exoskeleton can also include an override mechanism that prevents the brake disengagement mechanism from functioning when the exoskeleton is powered on and the controller has not failed. Additionally, the exoskeleton can include a user interface at one location, with the brake disengagement mechanism located at a different, limited access location, so that the user cannot accidentally activate the brake disengagement mechanism.