Visual contribution to walking in children with Developmental Coordination Disorder

Background : The motor co-ordination problems of children with Developmental Coordination Disorder (DCD) have been frequently associated with poor visuospatial processing. In order to extend these findings mainly based on fine motor experiments, the present study investigates the contribution of vision to the control of walking in children with DCD. Methods : Children with DCD (n = 12) walked at their preferred speed on a straight, firm and uncluttered walkway in a condition with normal lighting and in a dark condition. Spatiotemporal gait variables were assessed by means of a three-dimensional ProReflex camera system and compared with the gait pattern of matched, typically developing (TD) children (n = 12). Results : In normal lighting, the gait pattern of both groups was similar, with the exception of subtle differences in the temporal phasing, showing a slightly longer support phase in the children with DCD. In the dark, step frequency and step length were decreased in the children with DCD, resulting in a significantly slower walking velocity. In addition, the medio-lateral excursion of the centre of mass tended to increase in this group. In the TD children, adaptations to the spatiotemporal pattern remained absent. Conclusions : These results suggest that children with DCD are more dependent on global visual flow information than TD children for the maintenance of balance and the control of velocity during walking. This increased dependency on visual control might be associated with a poorly developed internal sensorimotor model