Procedural and Strategic Visuomotor Learning Deficits in Children With Developmental Coordination Disorder.

Purpose: Developmental coordination disorder (DCD) is characterized by poor coordination and clumsiness in children. Subjects often show unsteady gait, frequent tripping, and difficulty holding objects. Here we evaluated the implicit and explicit motor learning capabilities of children with DCD. Method: We assessed a total of 80 children (4-12 years old). These children were divided into two groups of 40 participants each. One group with DCD diagnosis and a control group. Using a prism adaptation paradigm, we evaluated whether DCD affects procedural visuomotor adaptation. This adaptation typically occurs during the laterally displacing prism adaptation task. We contrasted these results with the performance during a reversing prism adaptation task, which mainly places demands on strategic visuomotor learning. To solve both adaptation tasks, subjects must perform the same movements, but using two completely different approaches. Results: There was a significant variable error difference between groups, confirming a motor control deficit in individuals with DCD. This group also showed significant visuomotor learning deficits in the displacing task, including less adaptation and smaller aftereffect. The analysis on the reversing task revealed a significant larger number of subjects with DCD that could not adapt, suggesting significant strategic visuomotor learning deficits in this group too. Conclusions: These results demonstrate procedural and strategic visuomotor deficits in this sample of children with DCD.