1. Geriatrics Department, Brugmann University Hospital, Université Libre de Bruxelles, Place A. Van Gehuchten 4, 1020 Brussels, Belgium
2. Rehabilitation Research Group, Hospital del Mar Medical Research Institute (IMIM), Dr. Aiguader, 88, 08003 Barcelona, Spain
3. Geriatric Department, Centre Fòrum-Hospital del Mar, Parc de Salut Mar, Llull, 410, 08029 Barcelona, Spain
4. WHO Collaborating Centre for Public Health Aspects of Musculoskeletal Health and Ageing, Division of Public Health, Epidemiology and Health Economics, University of Liège, 4000 Liège, Belgium
5. Department of Geriatrics, Onze Lieve Vrouw Ziekehuis (OLV) Aalst, Moorselbaan 164, 9300 Aalst, Belgium
6. Department of Geriatrics, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, Jette, 1090 Brussels, Belgium
7. Physical Medicine and Rehabilitation Department, Hospital del Mar-Hospital de L’Esperança, Parc de Salut Mar, Pg. Marítim de la Barceloneta, 25-29, 08003 Barcelona, Spain
8. School of Medicine, Universitat Pompeu Fabra, Plaça de la Mercè, 10-12, 08002 Barcelona, Spain