1. Faculty of Science and Engineering, Anglia Ruskin University, Chelmsford, Essex CM1 1SQ, UK
2. Leon Root, MD Motion Analysis Laboratory, Hospital for Special Surgery, New York, NY 10021
3. Department of Biomechanics, Hospital for Special Surgery, New York, NY 10021
4. Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY 10021
5. Department of Orthopedics, Foot and Ankle Division, Hospital for Special Surgery, New York, NY 10021
6. Biomed Consulting, Inc., New York, NY 10044