1. Department of Orthopedic Surgery, Graduate School of Medicine, Hirosaki University, Hirosaki, Japan;
2. Meijo University, Nagoya, Japan;
3. Public Health Center, Okazaki Medical Association, Okazaki, Japan;
4. Department of Obstetrics and Gynecology, Graduate School of Medicine, Hirosaki University, Hirosaki, Japan; and
5. Department of Rehabilitation Medicine, Graduate School of Medicine, Hirosaki University, Hirosaki, Japan.