1. Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Japan
2. Department of Rehabilitation, Gunma University Graduate School of Health Sciences, Maebashi, Japan
3. Department of Orthopaedic Surgery, Saiseikai Maebashi Hospital, Maebashi, Japan
4. Department of Orthopaedic Surgery, Fujioka General Hospital, Fujioka, Japan
5. Department of Orthopaedic Surgery, Tone Central Hospital, Numata, Japan