Background: Tummy time, defined as an infant being placed on their stomach whilst they are awake and supervised, has been shown to have a positive effect on infant development and head shape. Tummy time can be influenced by a number of factors. Using a social ecological model, categories of potential variables can be examined to determine their influence on behaviours such as tummy time. The purpose of this systematic review was to examine potential correlates of tummy time in infants from birth to 12 months old.
Methods: Electronic databases were originally searched between March to December 2016. Included studies needed to be peer-reviewed, written in English, and meet a priori study criteria. The population was apparently healthy infants aged from birth to 12 months old. The article needed to contain an objective or subjective measure of tummy time as a dependent variable and examine the association between a demographic, psychological, behavioral, and/or environmental variable and tummy time. For this study, tummy time could include the ability of the infant to move whilst being positioned on their stomach, for example, the infant's ability to roll from back to front, or lift their head when lying on their stomach (prone positioning ability), or the capacity, time spent, age started, or parent attitudes/behaviours regarding the infant being placed on their stomach. The outcomes were the relationships between potential correlates and tummy time. Risk of bias was assessed at the individual study level using the Cochrane risk of bias assessment for observational studies.
Results: 15 articles representing 2372 unique participants from 7 countries were included. Correlates that were positively correlated with tummy time were age, prone sleeping, spending greater than 15 minutes whilst awake in tummy time when 2 months old, amount of time in the bath, order of achievement of prone extension and prone on elbow positions and parents/carers setting aside time for tummy time. Risk of bias of the included studies ranged from low to high.
Conclusions: Specific demographic, environmental and behavioral variables were found to be positively and negatively associated with tummy time. This evidence could assist future research regarding interventions to promote tummy time, enhance motor development, increase infant physical activity and contribute to future tummy time recommendations for parents and health care providers.