1 Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama, Wakayama, Japan.
2 Department of Medical Research and Management for Musculoskeletal Pain, Faculty of Medicine, 22nd Century Medical and Research Center, The University of Tokyo, Tokyo, Japan.
3 Department of Orthopaedic Surgery, Sagamihara Hospital, National Hospital Organization, Sagamihara, Kanagawa, Japan.
4 Department of Spine Surgery, Tokyo Yamate Medical Center, Japan Community Healthcare Organization, Tokyo, Japan.
5 Department of Biomedical Engineering, Faculty of Biology-Oriented Science and Technology, KinDai University, Kinokawa, Wakayama, Japan.