1. Research and Development Department, Nippon Sigmax Co., Ltd., Tokyo 160-0023, Japan
2. Department of Orthopaedic Surgery, Wakamatsu Hospital of University of Occupational and Environmental Health, Kitakyushu 808-0024, Japan
3. Hatakeyama Orthopaedic Sports Clinic, Kitakyushu 808-0841, Japan
4. Department of Rehabilitation Medicine, Wakamatsu Hospital of University of Occupational and Environmental Health, Kitakyushu 808-0024, Japan