1. Department of Mechanical and Materials Engineering, Human Mobility Research Centre, Queen's University, 130 Stuart Street, Kingston, ON K7L 3N6, Canada e-mail:
2. Department of Orthopaedic Surgery, Stanford University, 450 Broadway Street, Pavilion C, Redwood City, CA 94063 e-mail:
3. Department of Orthopaedics, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, 1 Hoppin Street, CORO West, Suite 404, Providence, RI 02903 e-mail:
4. Department of Orthopaedics, The Warren Alpert Medical School of Brown University, Rhode Island Hospital, 2 Dudley Street, Suite 200 Providence, RI 02905 e-mail:
5. The Hospital for Special Surgery, Weill Medical College, Cornell University, East River Professional Building, 4th Floor, 523 East 72nd Street, New York, NY 10021 e-mail: