1 Lower Limb Research Unit, Warwick Hospital, Lakin Road, Warwick, CV34 5BW, United Kingdom. amitatrey@doctors.net.uk. jonwaite@me.com. richard.carr@swft.nhs.uk. Steveyoung5@me.com.
2 John Scales Centre for Biomedical Engineering, UCL Institute of Orthopaedics & Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex, HA7 4LP. a.hart@ucl.ac.uk. j.meswania@ucl.ac.uk.
3 Department of Orthopaedics, St. Michael's Hospital, Toronto, ON, Canada. zmori086@gmail.com.