1. Department of Rehabilitation Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
2. Department of Mechanical Engineering, Seoul National University College of Engineering, Seoul, Korea.
3. Department of Physical Therapy, Konyang University, Daejeon, Korea.
4. Department of Rehabilitation Medicine, Chungnam National University Hospital and Chungnam National University College of Medicine, Daejeon, Korea.
5. Department of Rehabilitation Medicine, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Pusan, Korea.
6. Department of Rehabilitation Medicine, National Rehabilitation Center, Seoul, Korea.