Children with developmental coordination disorder demonstrate a spatial mismatch when estimating coincident-timing ability with tools.

Coincident timing or interception ability can be defined as the capacity to precisely time sensory input and motor output. This study compared accuracy of typically developing (TD) children and those with Developmental Coordination Disorder (DCD) on a task involving estimation of coincident timing with their arm and various tool lengths. Forty-eight (48) participants performed two experiments where they imagined intercepting a target moving toward (Experiment 1) and target moving away (Experiment 2) from them in 5 conditions with their arm and tool lengths: arm, 10, 20, 30, and 40 cm. In Experiment 1, the DCD group overestimated interception points approximately twice as much as the TD group, and both groups overestimated consistently regardless of the tool used. Results for Experiment 2 revealed that those with DCD underestimated about three times as much as the TD group, with the exception of when no tool was used. Overall, these results indicate that children with DCD are less accurate with estimation of coincident-timing; which might in part explain their difficulties with common motor activities such as catching a ball or striking a baseball pitch.

Effects of two distinct group motor skill interventions in psychological and motor skills of children with Developmental Coordination Disorder: A pilot study.

BACKGROUND: Children with Developmental Coordination Disorder (DCD) have an increased risk for mental health difficulties. OBJECTIVE: The present pilot study aimed to determine whether distinct group intervention programs improved several psychological variables (anxiety; adequacy and predilection for physical activity; participation, preferences, and enjoyment for activities) and motor skills from the perspective of a child with DCD as well as parental perceptions of motor skills, rate of function, and strengths and difficulties. METHODS: Eleven children participated in Program A and thirteen in Program B. Both involved 10 sessions of 1 h each. Program A focused on task-oriented activities in a large group involving motor skill training and collaboration and cooperation among children, while Program B was composed of three groups with a direct goal-oriented approach for training of skills chosen by the children. RESULTS: Results indicated that children improved motor skills after both programs, but showed distinct results in regards to other variables - after Program A, children showed higher anxiety and lower levels of enjoyment, even though parents detected an improvement in rate of function and a decrease in peer problems. With Program B, children decreased anxiety levels, and parents noted a higher control of movement of their children. CONCLUSIONS: Regardless of the group approach, children were able to improve motor skills. However, it is possible that the differences between groups may have influenced parents' perception of their children's motor and psychological skills, as well as children's perception of anxiety.

Tool length influences reach distance estimation via motor imagery in children with developmental coordination disorder.

PURPOSE: Children with developmental coordination disorder (DCD) often have difficulties with planning and generating a precise visuospatial representation of intended actions and using motor imagery to mentally represent motor behavior. Here, we aimed to extend the investigation of motor imagery in children with DCD by exploring its use with an estimation of reach paradigm that combines action representation and extension of space with tools. METHOD: Two groups of 18 children with DCD and typically developing (TD) matched controls were tested with an estimation of reach paradigm using a 20-cm (Experiment 1) and 40-cm (Experiment 2) tool. Conditions involved estimations via motor imagery with their arm, tool, and a switch-block (SB) involving an abrupt change of space with an "extension" from arm to tool and a "retraction" from tool to arm. RESULTS: No significant group differences were found with the 20-cm tool; however, with the 40-cm implement, children with DCD were significantly less accurate than their TD counterparts. CONCLUSIONS: Compared to TD children, those with DCD have more difficulty estimating reach distances using the longer of two tool lengths: 40 cm compared to 20 cm. This finding may be related to differences in quality of motor imagery and in the ability to create an effective internal model for action in this context. Furthermore, our results suggest that tool length may present an additional action processing constraint on children with DCD. Additional studies are necessary to determine other constraints that children with DCD have when integrating tool use with spatial judgments for reach actions, as well as provide rehabilitation insights that involve motor imagery combined with tool use.