Tummy time — placing a baby on his or her stomach while awake and supervised — can help your baby develop strong head, neck and shoulder muscles and promote certain motor skills. Tummy time can also prevent the back of your baby’s head from becoming flat (positional plagiocephaly).
A baby’s skull is soft and made up of several movable plates. If a baby’s head is left in the same position for long periods of time, the skull plates might move in a way that creates a flat spot. While it’s recommended that you place your baby on his or her back to sleep to reduce the risk of sudden infant death syndrome (SIDS), tummy time gives a baby the chance to experience a different position. This can help reduce the risk of flat spots.
In addition, research suggests that babies who spend time on their tummies crawl on their stomachs earlier than do babies who don’t practice tummy time. The more time babies spend on their tummies, the earlier they might begin to roll over, crawl on their stomachs, crawl on all fours and sit without support.
You can begin giving your baby tummy time when he or she is a newborn. Start by laying your newborn on his or her tummy across your lap two or three times a day for short periods of time. As your baby grows stronger, place him or her on a blanket on the floor. Arrange age-appropriate toys within his or her reach. As your baby gets used to tummy time, place your baby on his or her stomach more frequently or for longer periods of time.
For a 3- to 4-month-old baby, some research suggests aiming for at least 20 minutes of tummy time a day.
Continue reading at the Mayo Clinic