Relations between communication and motor skills in young children with Down syndrome: a brief report

Children with Down syndrome (DS) experience delays across multiple developmental domains, including communication and motor coordination. While prior studies have investigated these domains separately, few have examined their interrelation using population-level data. This study aimed to evaluate (1) differences between young children with DS and typically developing (TD) peers in early communication skills and motor-coordination difficulties, and (2) whether the relationship between these domains is similar across groups.

This brief report used data from the 2021-2022 National Survey of Children's Health, a nationally representative U.S. dataset including children aged 0-5 years. Children were categorized as having DS (parent-reported diagnosis) or typical development (no developmental delays). Early communication skills were assessed using 11 parent-report items (five receptive, six expressive). Motor coordination was assessed using two items reflecting chronic difficulty using hands or moving around. Chi-square tests were used to compare group differences and to examine associations between motor coordination and communication milestones within each group.

The sample included 90 children with DS and 24,988 TD children. Compared with TD peers, children with DS were less likely to achieve all early communication milestones and more likely to experience motor-coordination difficulties (p < .001). Within the DS group, those with motor-coordination difficulties were less likely to say one word (57.1% vs 80.6%), follow verbal directions (45.2% vs 72.2%), point to things (38.1% vs 69.4%), understand "in," "on," "under" (31.0% vs 58.3%), or use two words (19.0% vs 44.4%) compared to TD children (p < .05). The TD group showed significant associations between the acquisition of early communication skills and motor coordination difficulties for all the early communication skills recorded (p < .01).

Findings indicate a dynamic, bidirectional relationship between early motor coordination and communication skill acquisition in young children with DS, mirroring patterns observed in TD peers. Population-level evidence underscores the need for early interventions targeting both domains concurrently. Future prospective studies using standardized developmental assessments are warranted to clarify temporal relationships and inform early intervention strategies.