1. Department of Orthopaedic Surgery University of Pittsburgh Pittsburgh Pennsylvania USA
2. Biodynamics Laboratory, Department of Orthopaedic Surgery University of Pittsburgh Pittsburgh Pennsylvania USA
3. Department of Orthopaedic Surgery Nihon University School of Medicine Tokyo Japan
4. Department of Orthopaedic Surgery Kobe University Graduate School of Medicine Kobe Hyogo Japan
5. Department of Physical Therapy University of Pittsburgh Pittsburgh Pennsylvania USA