Babies are like little incomplete humans.
Sure, all the major parts are there, but there’s a lot of stuff missing.
They don’t have a lot of hair. They can’t walk. And they’re just figuring out how to breathe on their own.
One thing there seems to be some confusion about when it comes to what babies are born without… is kneecaps.
Do babies have kneecaps? Are they born without kneecaps?
The answer is… sort of.
The bones known as the kneecaps, or patellae if we’re using the scientific name, are present in babies at birth. However, the patella is made of cartilage at this point, or a firm, rubber-like material.
The cartilage hardens into bone through a process called ossification, usually by around the age of around 4.
Let’s dive in a little deeper and talk about how/why this happens, and more importantly, what it means for you as a parent.
What is a kneecap and what does it do?
The patella, or kneecap, not surprisingly is a bone in your knee that’s kind of circular / triangular in shape.
In essence, it covers and protects your knee joint from damage.
It also helps you extend your knee outward by providing more leverage for your quadricep muscles.
The patella is known as a sesamoid bone, which means it’s actually embedded into a ligament or tendon (in this case, the quadriceps).
Kneecaps seem pretty small, but they’re actually the largest of this kind of bone in our body!
How are kneecaps formed?
Like a lot of bones in our body, kneecaps start off as cartilage when we’re born.
Cartilage is a white, firm, rubbery material that acts as connective tissue. It’s present at the ends of a lot of our bones and joints for protection because of how elastic it is.
(If you want to know what cartilage feels like, just tug on your nose or ears… You’ll notice it’s firm, but still flexible.)
Some parts of our body contain or are made of cartilage and stay that way forever.
Others, like some key bones that aren’t fully formed at birth, harden over time through ossification.
In ossification (here’s the short version, anyway), nutrients are pumped into the cartilage and special cells begin to form hard bone from the inside out.
Over time, the softer cartilage is replaced by hardened bone.
When it comes to baby boys and girls and toddlers, their kneecaps should transform from soft cartilage to fully-formed petalla at around 4-years-old.
(Some sources say 3-5 years, as well.)
So why don’t babies need fully formed kneecaps?
OK, that’s enough sciencey stuff.
(Though there’s plenty to learn about ossification and the process of turning cartilage into bone. Fascianting!)
What we care about as parents is… what does this mean for us?
So the reason that babies don’t have hardened kneecaps is, basically, because they’re designed to fall a lot!
In their very earliest days of life, they’ll be pretty much stationary.
But pretty quickly they start crawling around on their hands and knees.
If you’ve crawled around on the floor recently, you probably noticed that it didn’t feel too good on your knees. Babies’ knees are a lot softer and more malleable than ours, so to them it feels perfectly fine.
From there, babies start:
- Walking (and falling)
- Running (and falling)
- Skipping (and falling)
- Climbing (and falling)
Seeing a pattern here?
The kind of abuse young kids put their bodies through would absolutely wreck most full-grown adults, in part because our bones have hardened over the course of years and no longer have the same springy, sponginess to them.
What else are babies born without? Do babies have knuckles? Do babies have elbows?
It’s really hard to say for sure, but most of the bones in a baby’s body go through this process.
They start off as rubbery cartilage in the womb, and remain soft at birth.
Over the course of a few years, these bones harden through ossification. And they’ll continue to get harder and harder for many years to come.
It’s quite possible that knuckles and elbows, like kneecaps, have some level of cartilage and softness to them at birth.
It’s also important to remember that a lot of babies will have plenty of “baby fat” covering these key joints, which can make them harder to identify.
Can babies get hurt crawling & do they need kneepads?
Babies have lots of built-in protection for bumps, bruises, and falls.
They’ve got that layer of baby fat, for one. And then we already talked about how their bones and kneecaps are soft and ready to absorb some impact.
But that doesn’t mean babies are invincible!
It’s definitely fair game to worry about them getting hurt. That’s what we do. We’re parents!
A pretty common question parents have seems to be: Is it safe for a baby to crawl on hardwood or tile floors?
(And do they need kneepads.)
I’m not a doctor and don’t claim to be, but the general consensus is that it should be safe for babies to crawl on hard surfaces.
Learning to crawl and navigate different tactile surfaces is a natural part of baby’s development. I wouldn’t go overboard manipulating the environment by making it “perfect” for baby to crawl on.
However, if your baby doesn’t LIKE crawling on a certain surface (hardwood, tile, or maybe he gets rugburns on the carpet), then I think it’s OK to look into some options.
But I’ll say again that in most cases these aren’t necessary at all for crawlers or new walkers.
(Another cool option if you’re really worried about baby getting hurt while crawling is to confine him or her, when possible, to a padded foam playmat like this one. They’re SUPER nice, look great in your house, and usually babies actually want to crawl and use their toys on them. We used one like it when our daughter was young and got a lot of good use out of these.)
So now you know… babies ARE born with kneecaps. But only sort of.
The structure that eventually becomes the kneecap, or patella, starts off as a rubbery cartilage formation and gradually hardens over time.
By the time your baby is a toddler (anywhere from 3-5 years old), the kneecaps should be fully formed. However, they’ll keep getting harder and harder until your kid is an adult.
This whole process helps protect babies and toddlers while crawling and taking their lumps as they learn to walk. Remember, crawling and falling as an adult doesn’t feel very good! So this is sort of nature’s way of keeping baby safe.
If you’re worried about your baby’s knees, you have a few options:
- Knee pads
- Padded foam play mats
- Keep them in pants
But in truth, most of these won’t be necessary for the average baby, who needs to crawl, feel the ground, get hurt, and learn from all of it in order to become a fully functioning kid.
Hope this helps, parents!