Q: Do babies have bones?
A: Yes they do. However most of their bones are the building blocks for future bones. Babies are born with around 300 cartilage parts that will eventually turn into 209 bones. Cartilage is dense connective tissue. This cartilage turns into hard bone through a process called ossification.
A good example of cartilage that becomes bone is the patella, or knee cap.
The cartilage that will eventually become the patella starts to form while the baby is developing in the mother’s uterus, around the seventh and eighth week of the pregnancy. Babies are a work in progress from the beginning.
When you put your baby on his/her tummy for play time they push against the floor with their arms and legs to pull themselves up. They are also stimulating their cartilage to begin the ossification process. Around 6 to 7 months of age a baby will begin to get ready to start the crawling game. Not all babies crawl, some actually go from sitting to standing to walking. However the majority of babies do crawl. They start by getting up on their hands and knees and rock back and forth. The pressure of putting their hands and knees on the ground is contributing to the ossification process. Everything a baby does has a purpose. It is an amazing thing to watch a baby master the art of crawling forwards. Thank goodness their little patellas are flexible enough to tolerate all that crawling around.
What makes the baby stand up? Babies are actually born with a walking reflex. It lasts for a few months and then disappears and comes back around as a child approaches their first birthday.
Our bones have growth plates on each end of our long bones. As a child grows these growth plates go from tissue to hard bone. For girls they typically show signs of an ossified kneecap around 3 years of age. Boys will have an ossified knee cap around 4 to 5 years. This is why it is so important that children engage in age-appropriate activities. The growth plates can be damaged during these formative years and cause of lifetime of pain.
Our bones continue to grow through our adolescence. It is believed we actually continue to build our bones into our early 20s. Then as we age we start to lose our bone mass. Weight-bearing exercise and eating foods rich in calcium help us maintain bone mass that our bodies worked so hard to develop when we were babies.
As we grow the cartilage cells divide and increase in number in the growth plates of our bones. Growth plates are near the ends of a child’s long bones. When we reach adolescence growth plates are replaced by solid bone.
Katie Powers, R.N., is a board-certified lactation consultant and perinatal educator at Manatee Memorial Hospital’s Family BirthPlace. Her column appears every other week in Healthy Living. Contact her at firstname.lastname@example.org.