1. S. Gianola, PT, Clinical Epidemiology Unit, IRCCS, Orthopedic Institute Galeazzi, Via R. Galeazzi, 4. 20161 Milan, Italy.
2. M. Gasparini, MD, Department of Rehabilitation, Asl Biella, Italy.
3. M. Agostini, PT, Laboratory of Kinematics and Robotics, IRCCS, Fondazione Ospedale San Camillo, Venezia, Italy.
4. G. Castellini, PT, COF Lanzo Hospital, Lanzo d'Intelvi, Como, Italy.
5. D. Corbetta, PT, Rehabilitation Department, San Raffaele Hospital, Milan, Italy.
6. P. Gozzer, PT, APSS Tn, Villa Igea, Trento, Italy.
7. L.C. Li, PT, PhD, Department of Physical Therapy, University of British Columbia, and Arthritis Research Centre of Canada, Vancouver, British Columbia, Canada.
8. V. Sirtori, PT, Rehabilitation Department, San Raffaele Hospital.
9. M. Taricco, MD, Rehabilitation Unit, University Hospital St Orsola–Malpighi Polyclinic, Bologna, Italy.
10. J.M. Tetzlaff, MSc, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada.
11. A. Turolla, PT, Laboratory of Kinematics and Robotics. IRCCS Fondazione Ospedale San Camillo.
12. D. Moher, PhD, Clinical Epidemiology Program, Ottawa Hospital Research Institute.
13. L. Moja, MD, Department of Biomedical Sciences for Health, University of Milan, and Clinical Epidemiology Unit, IRCCS, Orthopedic Institute Galeazzi.