1 Gait & Brain Lab, Parkwood Institute and Lawson Health Research Institute, Schulich School of Medicine & Dentistry, Department of Medicine and Division of Geriatric Medicine, and Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, N6A 3K7, Canada.
2 Internal Medicine, Section of Geriatric Medicine, Amsterdam Public Health, Amsterdam UMC, Locatie AMC, Meibergdreef 9, Amsterdam, North Holland 1105 AZ, The Netherlands.