Examining Transdiagnostic Patterns of Motor Differences: Preliminary Findings From the Consortium for Motor Behavior in Neurodivergence (COMBINE).

While some diagnostic groups are characterized in terms of motor features, others are at risk of overlooked motor challenges due to emphasis on social-cognitive features. These conditions often co-occur, making it difficult to determine the specific contribution of each to the overall pattern of observed motor challenges across neurodivergence. The COMBINE dataset included 262 cases (216 Male, 46 Female) with one or more neurodevelopmental conditions. We used generalized linear models to assess the effect of each of 4 diagnoses (autism, ADHD, DCD, CAS) on Movement Assessment Battery for Children (2nd edition, MABC-2) total score, Manual Dexterity domain score, Aiming & Catching domain score, and Balance domain score; age; sex, and diagnoses. Movement scores were low in all groups, with 77% of cases in the Red Zone (DCD likely). Diagnosis of DCD predicted lower overall scores and Manual Dexterity scores, diagnosis of ADHD predicted higher overall scores and Balance scores, and diagnosis of autism predicted lower Aiming & Catching scores. These results suggest motor challenges are clinically-significant across several neurodevelopmental conditions, and that some conditions have independent effects on domain-specific motor skills. This study is the first step toward determining whether each neurodevelopmental condition has a unique motor "signature", or if motor differences are ubiquitous across this population.