1. Department of Health Sciences, Faculty of Science, Amsterdam Movement SciencesVrije Universiteit Amsterdam Amsterdam The Netherlands
2. Stichting Rugpoli Delden The Netherlands
3. Department of NeurosurgeryLeiden University Medical Centre Leiden The Netherlands
4. Department of Anesthesiology, Centre of Pain MedicineErasmus MC Rotterdam The Netherlands
5. Department of Physiotherapy & Occupational TherapyAarhus University Hospital Aarhus Denmark
6. Department of Epidemiology and Biostatistics, Amsterdam Movement SciencesVU University Medical Center Amsterdam The Netherlands