1. Division of Spinal Cord Medicine, Pusan National University School of Medicine, Yangsan, Korea.
2. Department of Rehabilitation Medicine, Pusan National University School of Medicine, Yangsan, Korea.
3. Medical Research Institute, Pusan National University, Busan, Korea.
4. Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea.