Abstract
Background: To examine differences in sitting posture in infants at low- and high-risk for autism spectrum disorder and to establish the relationship between sitting postural control and other developmental domains. Methods: A total of 19 infants participated in the study. Eight infants at high-risk and 11 infants at low-risk for autism spectrum disorder. Sitting posture at 6 months was evaluated using a force platform while center of pressure data were acquired. We utilized traditional tools of center of pressure analysis, such as range, median frequency and frequency dispersion, as well as non-linear tools such as Sample Entropy for both the medial-lateral and anterior-posterior directions. At 12 months we used the Mullen Scales of Early Learning, the Communication and Symbolic Behavior Scales Developmental Profile™ and the Ages and Stages Questionnaire, the personal-social subscale. Findings: At 6 months none of the postural control measures showed statistically significant differences between groups. Infants at high-risk presented significantly lower scores in all behavioral domains than infants at low-risk at 12 months with fair effect sizes. Certain measures of postural control at 6 months could predict language and visual reception behavior at 12 months. Interpretation: Infants at high-risk for autism spectrum disorder present with delays in social, communication and language behavior as well as altered postural control in the first year of life. The present data support the possibility that motor skills and specifically postural control may drive the development in other domains.