[1] Oxford Univ Hosp NHS Fdn Trust, Physiotherapy Res Unit, Windmill Rd, Oxford OX3 7HE, England
[2] Univ Oxford, Nuffield Dept Orthopaed Rheumatol & Musculoskelet, Oxford, England
[3] Univ Warwick, Warwick Med Sch, Warwick Res Nursing, Coventry, W Midlands, England