Inter-limb coordination in a novel pedalo task: A comparison of children with and without developmental coordination disorder.

Children with Developmental Coordination Disorder (DCD) have been shown to have different coordination patterns on some tasks compared to their typically developing peers. However, it is unclear whether these differences are driven by the fact that typically developing children tend to be more practiced at the task on which coordination is being measured. The current study used a novel pedalo task to measure coordination in order to eliminate any practice differences. Thirty children (8 years -16 years), 15 with DCD and 15 without were recruited for this study. Children pedalled along an 8 m line 20 times. Movement of the 7th Cervical Vertebra, shoulders, elbows, wrists, hips, knees, ankles and toes was recorded. In terms of outcome measures, pedalling speed was not different between the groups but the coefficient of variation of speed was higher in the children with DCD indicating a less smooth movement. Coordination was measured by calculating angles at the shoulder, elbow, hip, knee and ankle. A higher correlation coefficient (more tightly coupled movement) and a greater variation in joint angle was seen in the typically developing children for specific joint segments. The relationship between group and movement outcome (smoothness of movement) was mediated by inter-limb coordination variability. Therefore, the poor coordination and slower learning generally reported in children with DCD could be due to a slower or less optimal exploration of motor solutions.