Consequences of comorbidity of developmental coordination disorders and learning disabilities for severity and pattern of perceptual-motor dysfunction.

Children with developmental coordination disorder (DCD) have difficulty learning and performing age-appropriate perceptual-motor skills in the absence of diagnosable neurological disorders. Descriptive studies have shown that comorbidity of DCD exists with attention-deficit/hyperactivity disorder (ADHD) and learning disabilities (LD). This study examined the consequences of the comorbidity of DCD and LD for the severity and pattern of perceptual-motor dysfunction. Compared to children with DCD without LD, children with comorbid DCD and LD performed lower on a standardized assessment of perceptual-motor ability. Furthermore, it appeared that children with combined DCD and LD have particular difficulty performing manual dexterity and balance tasks but not ball-skill tasks. Implications for understanding the relationship between LD and perceptual-motor problems are discussed. We conclude that the comorbidity of DCD and LD not only affects the severity of perceptual-motor dysfunction but also is associated with a distinctive pattern of perceptual-motor dysfunction.