Tummy time
Tummy time is an American colloquialism used to encourage parents to ensure that their infant children spend time in the prone position while awake and supervised.
In 1992, the American Academy of Pediatrics recommended babies sleep on their backs to prevent Sudden Infant Death Syndrome (SIDS). Although the rate of SIDS decreased by 50% since the Safe to Sleep campaign started in 1994, an unintended consequence was that babies missed out on the twelve or so hours they used to spend in the prone position and there was a sharp increase in skull deformations in infants. Along with tummy time, rotating the direction infants lie in their crib as well as avoiding too much time in car seats, carriers, and bouncers are behaviors recommended to alleviate the associated risks of infants sleeping in a supine position.