1. Nuffield Department of Clinical Neurosciences, The University of Oxford, Oxford, UK
2. Department of Clinical Medicine, The Danish Pain Research Center, Aarhus, Denmark
3. Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
4. Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, The University of Oxford, Oxford, UK