Primary Care Musculoskeletal Research Centre, Primary Care Sciences, Keele University, Keele, Staffs ST5 5BG, UK
*Corresponding author. Tel.: +44 1782 583924; fax: +44 1782 583911.
E-mail:[email protected]
Submitted October 10, 2007; received in revised form January 25, 2008; accepted February 15, 2008.