1. Centre for Clinical Research Sörmland, Uppsala University, Sveavägen, entré 9, Eskilstuna SE-631 88, Sweden
2. Department of Health, Medicine and Caring Sciences, Physiotherapy, Linköping University, Institutionen för hälsa, medicin och vår, Hus 511-001, Linköping SE-581 83, Sweden
3. Division Primary Care, Region Sörmland, Repslagaregatan 19, Nyköping SE-611 88, Sweden
4. Division Medical Service, Department of Radiology, Region Sörmland, Repslagaregatan 19, Nyköping SE-611 88, Sweden