Anita B Amorim1,2,3, Gustavo C Machado1,2, Chris G Maher1,2. 1. The University of Sydney, Sydney School of Public Health, Faculty of Medicine and Health, Sydney, New South Wales, Australia. 2. Institute for Musculoskeletal Health, Sydney, New South Wales, Australia. 3. The University of Sydney, Discipline of Physiotherapy, Sydney School of Health Sciences, Faculty of Medicine and Health, Sydney, New South Wales, Australia.