Tummy time is terrific, but your baby cannot stay in that position forever, no matter how entertaining you make it, nor how hard he works to lift his head.
Side lying is another great position for a young infant, one that is well-known by occupational therapists to give babies unique opportunities for head control, eye-hand coordination and visual coordination in those early months of life. Yes, vision! The connection between vision and balance is so strong in fact that every young infant should have side lying in their daily play time.
Of course, side lying is terrific for arm and head control as well as balance. Even though your child isn’t lifting his head, he is refining movements of his head, shoulders and arms while he is looking and reaching. That “top arm”, the one that is more free to reach, is being pulled down by gravity. This means that he is strengthening his shoulder every time he reaches up and out. When that happens, his body rotates just a bit and he has to coordinate that movement of the hand, the shoulder, and the ribcage. He will be practicing the fine control needed to roll over, and might develop that skill a little sooner as well. But the special skill that side lying supports is not rolling or reaching.
The unique benefit is that in side lying your baby can more easily bring both hands together, bring eyes and hands together, and coordinate both eyes without the normal movement reflexes interfering as much. You know, those reflexes that swing his head and arms back or to the side just as he is reaching out. He can independently control his head and arms to examine his hands using touch and vision, learning about these wonderful things at the ends of his arms. And he can tilt his head just a bit to look at his hands as he plays. Side lying supports but also stabilizes that wobbly little head, allowing him to bring both eyes into focus and helps him isolate eye movement from head movement at this early age. Guess what? Better eye control is known to help develop balance, and when you pick him up and he lifts his head, you will see better balancing of his head on his shoulders, and better sitting balance sooner! The gift that keeps on giving!!
Safety concerns: Never leave your newborn alone in side lying. He will not have the ability to clear his airway if he slides into an awkward position. This is not a sleeping position, it is a supervised play position. Side lying is most effective if you fold up a soft receiving blanket into a thickness that is approximately the width from his shoulder to his neck, and slide it under his head and cheek. Leave the area near his mouth and chin unsupported. You have reached success when you can draw a straight horizontal line from the center of his chest through the center of his chin, nose and forehead. Everything is aligned in the center of his body. Some active babies need a towel roll behind their whole head and back to feel stable, as they can feel that rolling movement when they reach or turn their head. Some also need a little towel roll under that “top leg”, to keep them from rolling forward. Again, supervised play is safest.
I should mention that placing your baby in positions like side lying and prone on his tummy relieve pressure on the back of his head, reducing the chance that he will develop a flattened skull, also known as “positional plagiocephaly”. My post was intended to explain the visual development that side lying supports, but as you can see, this position is great for so many reasons!
Read more about infant development here: Why Parents Used The Fisher-Price Rock and Play Sleeper: Desperation and Confusion and Kids With Low Muscle Tone: The Hidden Problems With Strollers.