1. Musculoskeletal and Rheumatological Physiotherapy, Faculty of Medicine and Surgery, University of Rome Tor Vergata, 00142 Rome, Italy
2. Private Practice “Kura” Clinic, 53047 Siena, Italy
3. Asl Sud-Est, Department of Rehabilitation, Valdichiana Senese, 53045 Siena, Italy
4. Asl Roma 3, Department of Rehabilitation, 00122 Rome, Italy
5. Private Practice “Physioup” Clinic, 00142 Rome, Italy
6. Private Practice “Riabilita” Clinic, 35030 Padova, Italy
7. Medical Statistics and Epidemiology, Centre for Clinical Research, Epidemiology, Modelling and Evaluation (CREME), Institute for Global Health, London NW3 2PF, UK