1. Departments of PM&R and Physical Therapy and Human Movement Sciences, Northwestern University
2. University of the West of England , Stapleton, Bristol, UK
3. Dorothy House Hospice , Bradford-on-Avon, Wilts, UK
4. Pain Research Institute, Faculty of Health and Life Science, University of Liverpool , Liverpool, UK
5. CentraCare Neurosciences Pain Center, CentraCare , St. Cloud, Minnesota, USA
6. Department of Anesthesiology and Pain Medicine, Rush University Medical Center , Chicago, Illinois, USA
7. Royal United Hospitals Bath NHS Foundation Trust , Bath, UK
8. Department of Anesthesiology, Vanderbilt University Medical Centers , Nashville, Tennessee, USA