1. Rehabilitation Medicine, Yonsei University College of Medicine, Yongin Severance Hospital, Yongin, Korea.
2. Rehabilitation Medicine, Bundang Jesaeng General Hospital, Seongnam, Korea.
3. Department of Statistics, Keimyung University, Daegu, Korea.
4. Department of Rehabilitation Medicine, School of Medicine, Chungnam National University, Daejeon, Korea.