Rehabilitation robotics aims to apply robotic technology to rehabilitation of patients with neuromuscular, musculoskeletal, and/or mental disease and/or injury to improve their ability and eventually help them return to the job of their choice. In a narrow sense, it is a truly interdisciplinary and translational research area combining robotics, biomechanics, system identification, and physiology (and many other relevant disciplines) to complement the current clinical practice by providing objective robotic assessment and intensity-adjustable long-duration treatment. In a broad sense, rehabilitation robotics benefits our community, nation, and, eventually, the world. With the development of aforementioned technologies for the clinical use, it is expected that the patients regain their ability for the activities of daily living (ADL) and for occupation, the family members of the patients can return to their job, and, consequently, the social and economic burden to the community, nation, and the world can be reduced.