Children with Developmental Coordination Disorder respond similarly to age-matched controls in both speed and accuracy if goal-directed movements are made across the midline

Abstract

Background The conventional view among many clinicians is that crossing the midline in children with Developmental Coordination Disorder (DCD) results in degradation of their performance. However, no kinematic data yet exist to support this view. We therefore tested this assumption in an experimental setting. Methods A group of age- and gender-matched children with DCD (n = 48) and a group of typically developing children (n = 48) were compared while performing goal-directed movements with a pen on a XY-tablet. We examined whether speed or accuracy changed if the goal-directed movements were made towards targets positioned either at the midline, the contralateral (crossed) side or the ipsilateral (uncrossed) side of the body midline. Results Our results showed that movements in the contralateral workspace were less accurate for both groups of children in the tested age range (6-11 years). The movements made towards the targets in the midline were the fastest, and the pen pressure for movements in the ipsilateral space was the highest. However, these effects were similar for children with and without DCD. As expected, children with DCD made more errors, were slower and pressed more erratically on their pen, but this difference was irrespective of the position of their hand in the workspace. Conclusion Crossing the midline in children with DCD for small amplitude movements (2.5 cm), as tested in this study, does not result in increased degradation of the goal-directed movements compared with their typically developing peers. This implies that, contrary to expectation, there is no evidence for a preferential deficit in DCD in brain structures involved in making movements in the contralateral workspace.