Footnotes

• Twitter @CGMMaher, @JillAHayden, @bsaragiotto, @tieparma, @matthewbagg

• Contributors All authors contributed equally to the letter.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests The authors have published trials and systematic reviews evaluating exercise for low back pain (the topic of the review we comment upon in this letter)

• Patient consent for publication Not required.

• Provenance and peer review Not commissioned; externally peer reviewed.