Why Babies Have a C-Shaped Spine

Unless you’ve recently visited a chiropractor, you probably haven’t thought much about the shape of your spine. As adults, our spines have a subtle S shape. There’s a curve below your neck, then a curve in the other direction through your mid back and another curve at your lower back.

Babies, on the other hand, have a C-shaped spine. Just one big curve. And it makes sense based on the way they’re curled up in the womb.

This is why newborns often curl back up into the fetal position. It’s the most comfortable position for their spines.

How babies’ spines develop

During fetal development, the spine starts out as a straight line. As the baby grows, the spine begins to curve into a C-shape. When they’re born, babies’ spines are not yet fully developed and are still quite flexible. 

The S-shape develops over time, as babies start to hold their heads up, crawl and then walk. But this development won’t just happen on its own. Tummy time is an important part of an infant’s spine development.

How tummy time helps spine development

When babies lie on their backs or even rest in car seats for long periods of time, it can put pressure on their backs and hinder the muscle development needed to form a healthy spine shape. But don’t panic that yours is spending too much time on their back. 

The safest way for babies to sleep is on their back until they’re about a year old. And babies spend a lot of time sleeping. Just make sure to carry your baby upright in your arms or a carrier to mix things up and keep them close. And of course, incorporate tummy time a few times each day.

Tummy time helps babies stretch and strengthen their neck, shoulders and back muscles. It teaches them to hold their heads up and starts the development of the curve at their neck. It also starts the progression that will lead them to roll, crawl and walk—the first and last step towards adding the final curve to that S-shaped adult spine.

Does your baby hate tummy time? Try upside down tummy time.

How to help support healthy spine development

Besides encouraging tummy time, you want your baby to get the nutrients they need for strong bones. These include calcium, which babies will get from breast milk or formula, and vitamin D, which should be administered in drop form each day. Both are considered essential nutrients for humans of all ages.