1. Osaka Police Hospital, 10–31 Kitayama-cho, Tennoji-ku, Osaka 543, Japan.
2. Department of Orthopaedic Surgery, Osaka University Medical School, 2-2 Yamadaoka, Suita 565, Osaka, Japan.
3. Department of Orthopaedics and Trauma, Worcester Royal Infirmary NHS Trust, Newton Road, Worcester WR5 1JG, UK.
4. Bobath Memorial Hospital, 1-6-5 Higashinakahama, Joto-ku, Osaka 536, Japan.
5. Osaka National Hospital, 2-1-14 Hoenzaka, Chuo-ku, Osaka 540, Japan.
6. Osaka Koseinenkin Hospital, 4-2-78 Fukushima, Fukushima-ku, Osaka 553, Japan.