Footnotes

• Contributors All authors contributed to devising the content, AM and ME analysed the data, ME wrote the first draft and all authors revised the manuscript.

• Funding PEDro is funded by the Motor Accidents Authority of New South Wales, the American Physical Therapy Association, the Australian Physiotherapy Association, the Motor Accident Insurance Commission (Queensland), the Victorian Transport Accident Commission (Australia), WorkCoverSA (Australia), the Norwegian Electronic Health Library, and the physiotherapy associations in the UK, Afghanistan, Austria, Bahamas, Belgium, Canada, Chile, Denmark, Fiji, Finland, Germany, Guatemala, Hong Kong, Ireland, Israel, Italy, Latvia, Lebanon, Lithuania, Luxembourg, Macau, Mexico, Namibia, Nepal, Netherlands, New Zealand, Norway, Pakistan, Philippines, Portugal, Saudi Arabia, Serbia, Singapore, Slovenia, Spain, Sri Lanka, Sweden, Switzerland, Taiwan and Thailand. CGM, CS and RH's research fellowships are funded by the National Health and Medical Research Council.

• Competing interests None.

• Provenance and peer review Commissioned; internally peer reviewed.