1. a Jockey Club Rehabilitation Engineering Centre , The Hong Kong Polytechnic University , Hung Hom, Kowloon, Hong Kong
2. b Department of Prosthetics and Orthotics , Prince of Wales Hospital , Hong Kong
3. c Department of Orthopaedics and Traumatology , The Chinese University of Hong Kong
4. d Department of Applied Biology and Chemical Technology , The Hong Kong Polytechnic University , Hung Hom, Kowloon, Hong Kong