1. Y Kurtaiş Gürsel, MD, is Assistant Professor, Faculty of Medicine, Department of Physical Medicine and Rehabilitation, University of Ankara, Ankara, Turkey
2. Y Ulus, MD, is Specialist in Physical Medicine and Rehabilitation, Department of Physical Medicine and Rehabilitation, Bayındır Hospital, Ankara, Turkey
3. A Bilgiç, MD, is Assistant Professor, University of Ankara, Faculty of Medicine, Department of Physical Medicine and Rehabilitation, University of Ankara
4. G Dinçer, MD, is Professor, Faculty of Medicine, Department of Physical Medicine and Rehabilitation, University of Ankara
5. GJMG van der Heijden, PhD, is Clinical Epidemiologist and Physiotherapist, Julius Center for Health Sciences and Primary Care, University Medical Center, Utrecht, the Netherlands