1. Scientific Center for Quality of Healthcare, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
2. Department of Manual Therapy, Faculty of Medicine and Pharmacy, Vrije Universiteit Brussel, Brussels, Belgium
3. Pain in Motion International Research Group (www.paininmotion.be), Vrije Universiteit Brussel, Brussels, Belgium
4. Practice Physiotherapy and Manual Therapy, Heeswijk-Dinther, The Netherlands
5. Department of Public Health and Research, Radboud University Nijmegen Medical Centre, Amersfoort, The Netherlands
6. Department of Physiotherapy, Human Physiology and Anatomy, Faculty of Physical Education and Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium
7. SOMT University of Physiotherapy, Amersfoort, The Netherlands