1. M Hadders-Algra, MD, PhD, is Professor of Developmental Neurology, Department of Developmental Neurology, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, 9713 GZ Groningen, the Netherlands
2. JC van der Heide, PT, PhD, is Researcher, Department of Developmental Neurology, University Medical Centre Groningen, University of Groningen
3. JM Fock, MD, is Pediatric Neurologist, Department of Developmental Neurology, University Medical Centre Groningen, University of Groningen
4. E Stremmelaar, MD, is Pediatrician, Department of Paediatrics, University Medical Centre Groningen, University of Groningen
5. LA van Eykern is Electronic Engineer, Department of Developmental Neurology, University Medical Centre Groningen, University of Groningen
6. B Otten, PhD, is Professor of Neuromechanics, Center for Human Movement Sciences, University of Groningen