1. Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
2. Department of Physiotherapy, University College of Northern Denmark, Aalborg, Denmark.
3. Multidisciplinary Pain Center Naestved, Naestved Hospital, Naestved, Denmark.
4. Smertefys.nu, Physiotherapy Clinic, Copenhagen, Denmark.
5. Pain Research Group, Pain Center, Department of Anesthesiology and Intensive Care Medicine, Odense University Hospital, Odense, Denmark.
6. Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark.