1. Korea National Rehabilitation Research Institute, Korea National Rehabilitation Center, Seoul, Republic of Korea
2. Department of Medicine, Graduate School, Kyung Hee University, Seoul, Republic of Korea
3. Department of Medical Education and Humanities, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
4. Department of Preventive Medicine, College of Medicine, Korea University, Seoul, Republic of Korea
5. Department of Preventive Medicine, College of Medicine, Kyung Hee University, Seoul, Republic of Korea