1. Department of Physical Medicine and Rehabilitation, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Korea.
2. Department of Rehabilitation Medicine and Rehabilitation Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, Korea.
3. Pulmonary Rehabilitation Center, Gangnam Severance Hospital, Seoul, Korea.