1. Department of Rehabilitation Medicine, Seoul Veterans Hospital, Seoul 134-791, Korea.
2. Center of Prosthetics and Orthotics, Seoul Veterans Hospital, Seoul 134-791, Korea.
3. Department of Rehabilitation Medicine, Yeongju Municipal Hospital, Yeongju 750-871, Korea.
4. Department of Rehabilitation Medicine, Bestone Geriatric Hospital, Yongin 446-908, Korea.
5. Department of Rehabilitation Medicine, Gongju Health Center, Gongju 314-802, Korea.