1. Diagnostic Centre, Region Hospital Silkeborg, Silkeborg, Denmark
2. Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark
3. Musculoskeletal Statistics Unit, Parker Institute, Department of Rheumatology, Copenhagen University Hospital, Frederiksberg, Denmark
4. Institute of Sports Science and Clinical Biomechanics, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark