Early gross motor performance is associated with concurrent prelinguistic and social development.

Background: To study how early gross motor development links to concurrent prelinguistic and social development.

Methods: We recruited a population-based longitudinal sample of 107 infants between 6 and 21 months of age. Gross motor performance was quantified using novel wearable technology for at-home recordings of infants' spontaneous activity. The infants' prelinguistic and social development was assessed in parallel with a standardized parental questionnaire (Infant Toddler Checklist). The developmental trajectories of motor, prelinguistic, and social performance were inspected longitudinally at individual level, and correlated to each other to measure the relative, age-adjusted advance in performance (z-scores).

Results: Advanced gross motor maturation (higher z-score) links to more advanced prelinguistic development (β = 0.033, p = 0.016, R² = 0.706) and social development (β = 0.038, p = 0.025, R² = 0.600). When looking at specific gross motor skills, an increased amount of independent movement (crawling, standing, walking) links to more advanced prelinguistic and social abilities.

Conclusion: We introduce a novel approach that measures individual level gross motor development longitudinally at high resolution from child's spontaneous movements at home. This approach shows that age-adjusted relative advance in motor performance is linked to concurrent prelinguistic and social development, supporting the idea of developmental interaction across neurocognitive domains.

Impact: Early gross motor, prelinguistic, and social developments show trackable idiosyncratic trajectories. Maturity in gross motor performance links to concurrent prelinguistic and social development. Gross motor performance can be assessed reliably and objectively from infants' spontaneous activity using unsupervised wearable recordings in their native environment, the homes. The present methodology with longitudinal quantitative assessments and age-adjusted modeling with z-scores introduce a potential paradigm shift to studying early neurodevelopment in the context of pediatric health, benchmarking of therapeutic interventions, and other developmental studies.