Developmental sequences of two-handed catching: how do children with and without developmental coordination disorder differ?

The present study examined the movement patterns in children with developmental coordination disorder (DCD) and their age-matched controls (AMC) while catching two-handed. First, a cross-sectional study was conducted to investigate developmental characteristics within the three body component actions (arm, hand, and body) of two-handed catching hypothesized by Haywood and Getchell (2005). Data analyzed from 36 children (18 DCD, 18 AMC) aged 7-10 years who caught a ball 10 times, two-handed, showed that hypothesized sequences for the arm, hand, and body met the prelongitudinal screening criteria proposed by Roberton (1978), Langendorfer (1982), and Roberton, Williams, and Langendorfer (1980). In light of this, the second part of the study used these sequences to evaluate the movement patterns of 10 children with and 10 without DCD, aged 7-8 years. The data revealed that children with DCD displayed less advanced modal developmental sequence levels than AMC children with respect to the arm and body action components. (p <or= 0.01) Children with DCD also exhibited less advanced developmental profiles than the AMC children (p <or= 0.05), the group modal profiles being A2-H2-B2 and A3-H3-B3, respectively. These data also show that each child with DCD exhibited more developmental profiles over the 30 trials than the AMC children (p <or= 0.01) and that each DCD child's modal developmental profile was unstable (Roberton, 1977). Thus, over trials children with DCD link together different action patterns of the arm, hand, and body, suggesting that they have not yet developed a stable pattern of coordination to satisfy the task constraints.