1. ORTHOMOTION, City Klinik Thun; Marktgasse 17 Thun Switzerland 3600
2. University of Ioannina; School of Medicine; Leoforos Stavrou Niarhou Ioannina Greece 45110
3. Jewish General Hospital, Lady Davis Institute, McGill University; Centre for Clinical Epidemiology; 3755 Cote Ste-Catherine Road Montreal QC Canada H3T 1E2
4. University of Bern; Institute of Social and Preventive Medicine (ISPM); Finkenhubelweg 11 Bern Switzerland 3005
5. Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University; Cochrane Netherlands; Room Str. 6.126 P.O. Box 85500 Utrecht Netherlands 3508 GA