1. University of Oxford and the Arthritis Research UK Centre for Sport, Exercise, and Osteoarthritis; Oxford UK
2. University of Oxford, Oxford, UK, and University of Southampton; Southampton UK
3. FIMIM-Parc Salut Mar and Red Tematica de Envejecimiento y Fragilidad (RETICEF); Barcelona Spain
4. University of Oxford, Oxford
5. University of Oxford, Oxford, UK, FIMIM-Parc Salut Mar and RETICEF, Barcelona, Spain, and GREMPAL Research Group, IDIAP Jordi Gol Primary Care Research Institute, Universitat Autònoma de Barcelona; Barcelona Spain