1. Research Unit of Musculoskeletal Function and Physiotherapy, Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
2. Department of Rehabilitation, Aeroe Municipality, 5970 Aeroeskoebing, Denmark
3. The Parker Institute, Department of Rheumatology, Copenhagen University Hospital, 2000 Frederiksberg, Copenhagen, Denmark
4. Bergen University College, Institute of Occupational Therapy, Physiotherapy and Radiography, Department of Health Sciences, 5020 Bergen, Norway