Children with Autism Spectrum Disorder, Developmental Coordination Disorder, and typical development differ in characteristics of dynamic postural control: A preliminary study.

Background: Autism Spectrum Disorder (ASD) and Developmental Coordination Disorder (DCD) are developmental disorders with distinct definitions and symptoms. However, both conditions share difficulties with motor skills, including impairments in postural control. While studies have explored postural sway variables in children with DCD and ASD as compared to typical development (TD), few have used kinematic data to assess the magnitude of differences between these two neurodevelopmental conditions. There are few sensitive and specific measures available to assess balance impairment severity in these populations.

Research Question: Do individuals with ASD, DCD, and TD differ in dynamic postural control?

Methods: We quantified postural control differences between ASD, DCD, and TD during a dynamic balance task. 10 ASD, 10 DCD, and 8 TD agematched children completed a dynamic postural control task in a virtual environment. They leaned to shift their center of pressure (CoP) to match a user-controlled object to an oscillating target (0.1 Hz-0.8 Hz).

Results: The DCD group had higher CoP accelerations compared to ASD or TD. While the DCD and TD groups did not differ in their medial-lateral velocity, the ASD group had low medial-lateral velocity and acceleration as compared to DCD and TD. ASD group velocity and acceleration did not differ from that of the TD group in the anterior-posterior direction. Higher accelerations in the DCD group reflected non-fluid movements; by contrast, the ASD group had slower, more fluid movements. Results may reflect differences in how children with ASD and DCD plan, execute, and modify motor actions.

Significance: This study demonstrates the potential utility of CoP acceleration and velocity as a sensitive and specific means of differentiating between ASD, DCD, and TD. Results indicating group differences between ASD and DCD in velocity and acceleration profiles represent an important step toward understanding how these populations modify motor plans during dynamic tasks.