1. School of Medicine, Keele University , Newcastle , UK
2. Department of Orthopaedic Surgery, Duke University School of Medicine , Durham, North Carolina , USA
3. Department of Physical Therapy, University of Florida , Gainesville, Florida , USA
4. Brooks Rehabilitation , Jacksonville, Florida , USA
5. Department of Psychiatry, University of Pittsburgh School of Medicine , Pittsburgh, Pennsylvania , USA
6. Department of Physical Therapy, University of Pittsburgh School of Health and Rehabilitation Sciences Pittsburgh , Pennsylvania , USA
7. Duke Clinical Research Institute, Duke University , Durham, North Carolina , USA
8. Department of Population Health Sciences, Duke University School of Medicine , Durham, North Carolina , USA