1. Rehabilitation Research Group, Hospital del Mar Research Institute, Dr. Aiguader, 88, 08003 Barcelona, Catalonia, Spain
2. Physical Medicine and Rehabilitation Department, Parc de Salut Mar (Hospital de l’Esperança), Sant Josep de la Muntanya 12, 08024 Barcelona, Catalonia, Spain
3. Department of Medicine, Universitat Autònoma de Barcelona, Passeig de la Vall d’Hebron, 119-129, 08035 Barcelona, Catalonia, Spain
4. Geriatrics Department, Brugmann University Hospital, Université Libre de Bruxelles, Place A. Van Gehuchten 4, 1020 Brussels, Belgium
5. WHO Collaborating Centre for Public Health Aspects of Musculo-Skeletal Health and Ageing, Division of Public Health, Epidemiology and Health Economics, University of Liège, 4000 Liège, Belgium
6. Faculty of Health and Life Sciences, Universitat Pompeu Fabra, Aiguader 80, 08003 Barcelona, Catalonia, Spain
7. Department of Radiology, Biomedical Research Institute Imaging Research Unit, Diagnostic Imaging Institute, Doctor Josep Trueta University Hospital of Girona, Avinguda de França, s/n, 17007 Girona, Catalonia, Spain