1. Department of Orthopaedics, Ryhov Hospital;
2. Neuro-Orthopedic Center, Ryhov Hospital, Jönköping;
3. Department of Medical and Health Sciences, Division of Physiotherapy, Faculty of Health Sciences, Linköping University, Linköping;
4. Department of Neuroscience, Neurosurgery, Uppsala University Hospital, Uppsala;
5. Department of Physiotherapy, School of Health, Care and Social Welfare, Mälardalen University, Västerås; and
6. Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg;
7. Spine Center Göteborg, Gothenburg, Sweden