1. Department of Physical Medicine and Rehabilitation, National Health Insurance Service Ilsan Hospital, Goyang-si, Gyeonggi-do, Korea
2. Yonsei University Graduate School of Medicine, Seoul, Korea
3. Department of Rehabilitation Medicine and Rehabilitation Institute of Neuromuscular Disease, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
4. Pulmonary Rehabilitation Center, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
5. Department of Rehabilitation Medicine, SRC Rehabilitation Hospital, Gwangju-si, Gyeonggi-do, Korea