Motor planning and movement execution during goal-directed sequential manual movements in 6-year-old children with autism spectrum disorder: A kinematic analysis*

Background: Atypical motor functioning is prevalent in children with autism spectrum disorder (ASD). Knowledge of the underlying kinematic properties of these problems is sparse. Aims: To investigate characteristics of manual motor planning and performance difficulties/diversity in children with ASD by detailed kinematic measurements. Further, associations between movement parameters and cognitive functions were explored. Methods and procedures: Six-year-old children with ASD (N = 12) and typically developing (TD) peers (N = 12) performed a sequential manual task comprising grasping and fitting a semicircular peg into a goal-slot. The goal-slot orientation was manipulated to impose different motor planning constraints. Movements were recorded by an optoelectronic system. Outcomes and results: The ASD-group displayed less efficient motor planning than the TD-group, evident in the reach-to-grasp and transport kinematics and less proactive adjustments of the peg to the goal-slot orientations. The intra-individual variation of movement kinematics was higher in the ASD-group compared to the TD-group. Further, in the ASD-group, movement performance associated negatively with cognitive functions. Conclusions and implications: Planning and execution of sequential manual movements proved challenging for children with ASD, likely contributing to problems in everyday actions. Detailed kinematic investigations contribute to the generation of specific knowledge about the nature of atypical motor performance/diversity in ASD. This is of potential clinical relevance.