[1] Milton Keynes Univ Hosp, Orthopaed Dept, Milton Keynes MK6 5LD, Bucks, England
[2] UCL, Sch Pharm, London WC1N 1AX, England
[3] St Marys Univ, Dept Sport & Exercise Sci, Twickenham TW1 4SX, England
[4] Univ Brighton, Med Educ Dept, Brighton BN1 9PH, E Sussex, England
[5] Univ Cambridge, Dept Clin Neurosci, Cambridge CB2 2PY, England
[6] Guys & St Thomas NHS Trust, Orthopaed Dept, London SE1 9RT, England