1. Rehabilitation Center, Saiseikai Kanagawaken Hospital: 6-6 Tomiyacho, Kanagawa-ku, Yokohama-shi, Kanagawa 221-0821, Japan
2. Graduate School of International University of Health and Welfare, Japan
3. Department of Medical Research and Management for Musculoskeletal Pain 22nd Century Medical and Research Center, Faculty of Medicine, The University of Tokyo Hospital, Japan