1. KJ Murray, PhD, is Physiotherapist, Dizzy Day Clinics, Melbourne, Victoria, Australia
2. KD Hill, PhD, is Director, Preventive and Public Health Division, National Ageing Research Institute, and School of Physiotherapy, The University of Melbourne, Melbourne, Victoria, Australia
3. B Phillips, PhD, is Associate Professor of Allied Health, School of Physiotherapy, LaTrobe University, Melbourne, Victoria, Australia
4. J Waterston, MD, FRACP, is Neurologist and Senior Lecturer, Department of Medicine, Monash University, Melbourne, Victoria, Australia