Assessment of Motor Performance in Children with Autism Spectrum Disorder: The Relationship Between Clinical Characteristics and Intelligence—An Exploratory Cross-Sectional Study

Background and Objectives: Evidence on motor performance in children with autism spectrum disorder (ASD) is scarce and inconsistent. The association of motor impairments with autism severity and intelligence remains insufficiently studied. We aimed to examine motor performance parameters in children with ASD compared with typically developing (TD) peers. Materials and Methods: In this cross-sectional study, a convenience sample of 26 children with ASD, aged 4–10 years, was recruited from specialized centers in KSA, alongside 27 age- and sex-matched TD children. For the ASD group, severity (Childhood Autism Rating Scale, CARS-2) and intelligence quotient (Stanford–Binet Intelligence Scale, SB5) were extracted from medical records. CARS-2 score was utilized to categorize children with ASD into two groups (mild-to-moderate and severe groups). All study children were assessed for gross and fine motor skills using the Movement Assessment Battery for Children-2 (MABC-2), balance, muscle strength, endurance, and flexibility. Results: ASD groups recorded significantly lower scores in all MABC-2 component areas when compared to the TD group (p < 0.001). Aiming and catching percentile was significantly lower in the severe ASD group compared to the mild-to-moderate group (p = 0.05). Furthermore, children with ASD exhibited increased hypermobility, predominantly at the elbow joints, reduced grip strength, shorter distance in the modified 6 min walk test, and lower standing long-jump performance (p < 0.001) when compared to TD group; however, no significant difference was recorded between the ASD groups. Spearman correlation revealed that aiming and catching was negatively correlated with autism severity (CARS-2) (r = −0.38, p = 0.05) and positively with IQ (r = 0.51, p = 0.03). Aiming and catching was positively correlated with grip strength (r = 0.55, p = 0.003), endurance (r = 0.58, p = 0.002), and jump distance (r = 0.44, p = 0.03), while balance was positively correlated with grip strength (r = 0.44, p = 0.02). Conclusions: Children with ASD exhibit significant impairments in gross and fine motor performance compared with TD peers, accompanied by hypermobility, reduced strength, and diminished endurance. Notably, aiming and catching ability correlated with both IQ and autism severity as well as specific motor parameters, suggesting its potential as a clinical marker of motor–cognitive interaction in ASD.