1. Department of Rehabilitation Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands;
2. Physiotherapy Practise, Inter-Fysio, Groningen, The Netherlands;
3. Department of Clinical Health Science, Faculty of Medicine, University of Utrecht, Utrecht, The Netherlands;
4. Physiotherapy Practise, PrengerHoekman, Winschoten, The Netherlands;
5. Department of Oral and Maxillofacial Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands