1 Department of Physical and Rehabilitation Medicine, University Hospitals Leuven, Belgium Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy and IRCCS Fondazione Don Gnocchi, Milan, Italy Cochrane Child Health Field, Department of Pediatrics, University of Alberta, Edmonton, AB, Canada Department of Physical Medicine and Rehabilitation, Vanderbilt University Medical School, Nashville, Tennessee, Editor in Chief, American Journal of Physical Medicine and Rehabilitation.