1. Department of Community Health Nursing, Division of Health Sciences and Nursing, Faculty of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
2. Department of Orthopedic Surgery, Okinawa Prefectural Nanbu Medical Center and Children’s Medical Center, Haebaru Town, Okinawa 901-1193, Japan
3. Doi Orthopedic Clinic, Takatsuki City 569-0803, Japan
4. Department of Orthopedic Surgery, Asahigawasou Rehabilitation and Medical Center, Okayama 703-8207, Japan