Interrelation between Early Motor and Language Development in Infants with Down Syndrome: Preliminary Results

Research Objectives: We aim to examine the interrelation between developmental domains in infants with Down syndrome (DS). DS is the most common genetic condition and causes significant development delays in the motor, cognitive, and language domains. Motor development is closely associated with cognitive and language development in typically developing (TD) infants and advances in motor development have developmental “cascading” effects on other domains. This interrelation has not been studied in infants with DS.

Design: Longitudinal, interventional.

Setting: Home/natural environment.

Participants: 4 infants with DS (1F/3M), mean age 9mo 20 days at Time 1 and 14mo 29 days at Time 2.

Interventions: Treadmill stepping and “sticky mittens” training.

Main Outcome Measures: Multi-domain developmental assessment using the Bayley Scales of Motor Development (4th Edition) as well as the biomechanical variables of reaching and grasping.

Results: Peak acceleration of the arm during reaching and the percentage of reaches that resulted in touches without a successful grasp were negatively correlated with the Fine Motor scaled scores on the Bayley (r=-0.678, p=0.064 and r=-0.811, p=0.015 respectively). Language standard scores on the Bayley were positively correlated with the Fine Motor scaled scores (r=0.864, p=0.006), and negatively correlated with both the peak acceleration of the arm (r=-0.770, p=0.025) and the percent of touches without a successful grasp (r=-0.750, p=0.030). Changes in Fine Motor scaled scores and changes in Language standard scores between the two time points were positively correlated (r=0.999, p= < 0.0001).

Conclusions: The close relationship between motor and language skills seen in TD infants was observed in infants with DS. Our preliminary results suggest that poor grading of force during reaching may contribute to higher arm accelerations in infants with DS. Further, the significant corrections between fine motor and language development suggest that these two domains are highly interrelated in infants with DS. This pilot work demonstrates a clear relationship between motor and language skills in infants with DS and future work is warranted.

Author(s) Disclosures: None of the authors have any conflicts of interest to disclose.