1. Department of Physiotherapy and Occupational Therapy, Glostrup University Hospital, Glostrup, Denmark,
2. Center of Rheumatology and Spine Diseases, Glostrup University Hospital, Glostrup, Denmark,
3. Nursing and Health Science Research Unit, Glostrup University Hospital, Glostrup, Denmark, and
4. Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark