Longitudinal Associations Between Movement Behaviours and Development Among Infants Using Compositional Data Analysis

Background: The study examined the longitudinal associations of sleep time, restrained time, back time and tummy time with development in a sample of infants using compositional data analysis. Methods: Participants were a subsample of 93 parent–infant dyads from the Early Movers project in Edmonton, Canada. Parents completed a 3-day time-use diary at 2, 4 and 6 months of age. Time spent in four mutually exclusive movement behaviours were calculated representing sleep (i.e., sleep time), sedentary behaviour (i.e., restrained time and back time) and physical activity (i.e., tummy time). Communication, fine motor, gross motor, personal-social, problem solving and total development were measured at 2, 4 and 6 months of age with the Ages and Stages Questionnaire (ASQ-3). Gross motor development was also measured by a physiotherapist using the Alberta Infant Motor Scale (AIMS) at 6 months. The age six major gross motor milestones (i.e., independent sitting, crawling, assisted standing, assisted walking, independent standing, independent walking) were achieved according to World Health Organization criteria, in the first 18 months of life, were calculated. Results: The composition of movement behaviours across time points was significantly associated with: ASQ-3 gross motor, problem solving and total development scores over time, total and percentile AIMS scores at 6 months and independent standing and walking milestones (ilr model p-value: < 0.001–0.045; model R2: 0.02–0.15). More sleep time or tummy time relative to other movement behaviours was associated with more advanced development and earlier achievement of some milestones. The opposite was observed for back time. Associations with restrained time were mixed. The optimal movement behaviour durations (minutes/day) for AIMS and WHO milestone outcomes, were 38–43 of tummy time, 51–54 of back time, 43–96 of restrained time and 845–900 of sleep time. Conclusions: Targeting healthy movement behaviour patterns in infants may be a promising health promotion strategy.