Do Penguins Have Knees? (Plus Interesting Facts About Ankles, Elbows and Hips)

Do penguins have knees, and if so do they use them at all? I was interested to find this out, as I had seen a book that has this question as the title. What I found out was pretty surprising.

As it turns out there is more to this question than meets the eye, which you will see below if you keep reading.

So do penguins have knees? Yes penguins do have knees. They are tucked up inside of their bodies, and are not visible. Penguins don’t use their knees for walking as this is very difficult due to the location of the knees. They can use them to swim, slide on the ice, and to incubate their eggs in their cold living conditions.

Crazy right? Penguins have knees, we just can’t see them! I’ve provided more information below about how exactly a penguin’s legs are structured, and how they can use these for a number of things.

I’ve also gone into some detail about other parts of a penguin such as their elbows, hips and ankles. Keep reading if you want to find out more about a penguin’s knees and how exactly they use them!

Do Penguins Have Knees?

This skeleton of a penguin clearly shows that it has knees – H. Zell, CC BY-SA 3.0, via Wikimedia Commons

Now when you see a penguin waddling around, with their short legs, you could be forgiven for asking the question do penguins have knees. But just because you cannot see them, it doesn’t mean they don’t have them.

Penguins do in fact have knees. A penguin’s leg is made up of a short femur, a knee, and tibia and fibular bones.

Unlike other birds, a penguin’s bones are extremely dense. For flighted, or volant birds, bones are fairly hollow. This of course aids them with flying.The lighter a bird is, the easier it will be for them to glide through the air.

Penguins do not glide through the air, but instead glide through water. Being more dense allows them to dive deep below the surface, as the added weight of their skeleton stops them from being too buoyant.

To aid with the swimming and diving process, penguins also need to be streamlined. This is one of the reasons that you cannot see their knees. Penguins also have great eyesight, which they need to be able to see underwater.

A penguin’s knees are tucked up inside of their body, and this is why they appear to have such short legs. This gives the penguin less drag when swimming through the water. It aids with both speed and the ability to dive deeply.

Penguins use their feet like rudders on a boat to steer them as they glide through the water. The webbing on their feet helps with this greatly too.

Volant (flighted) birds have a large sternum, which helps greatly with the process of flying. Penguins are flightless birds, known as ratites.

Now they may not fly, but they still need this sternum. Instead of aiding with the flight process through the air, this helps them to fly through the water instead. Penguins also have a tail which helps them to steer in the water.

So do penguins have knees? Yes they do. You just can’t see them. In fact people will often mistake the ankle joint of a bird for it’s knee, and due to the way this joint bends, people wrongly think that the knees of birds bend in the opposite direction to that of humans and other mammals.

Another interesting thing about a penguin’s knees from an evolutionary point of view is the way in which they can aid incubation. A penguin can hold eggs between it’s knees, which are tucked up inside of it’s body.

This allows the penguin to keep the eggs warm, in what are bitterly cold living conditions. Penguins are interesting creatures, and there are many things that I didn’t know about them until I started researching.

For example, did you know that penguins do not go to the toilet in the same way we do at all? I was so fascinated by this that I wrote a whole post about the question do penguins pee?

Do Penguins Have Kneecaps?

So in answering the question do penguins have knees, we really need to discuss the knee cap too. As we have said, they do have knees, so surely a penguin has knee caps too right?

Well then do penguins have kneecaps? Penguins do in fact have kneecaps, or patellas. It’s just that as you can’t see their knees due to them being tucked up inside of their body, you would never be able to tell if a penguin did or didn’t have kneecaps.

Most birds and even reptiles do not have kneecaps. As I said above, the penguin does, and so does the ostrich too.  Ostriches in fact have two in each leg, which is actually designed to make the bending of the leg more difficult and not easier.

Why Don’t Penguins Use Their Knees?

Penguin Swimming Using Knees
Penguins use their knees to help them swim fast!

This is another question to cover when thinking about do penguins have knees. If they do, as I said above, then why don’t they use their knees.

Just because we can’t see a penguin’s knees, and just because we see them waddling around, this does not mean that penguin’s do not use their knees. They do in fact use them more than you would think.

Let’s take walking first. Using their knees in the traditional sense that we do is simply not the most effective way for penguins to walk. Taking shorter steps on slippery surfaces makes it less likely that they will fall.

Due to the composition of their skeleton, and the fact that their legs are tucked up inside of their bodies, they can’t really use them as we do for walking.

As I said above though, they can use them for a great deal of other things, such as incubating their eggs. You can think of this is a kind of trade off. Yes, they may not be able to use their knees in the way that we can for walking, but they are able to use them to incubate their eggs, which is essential in their cold living conditions.

Penguins are also able to use their knees to aid in movement, just not in the traditional sense. I’m sure you’ve seen a penguin sliding across sheets of ice on TV before.

Penguins need to use their knees in order to do this. The act of bending their knees and pushing with their feet generates the force for them to be able to slide along the ice like this.

Penguin Sliding Using knees
Penguins use their knees to slide on ice and snow!

This is also the same for swimming. Penguins will use their knees in the water to help propel them. Bending their knees and then pushing to extend their legs helps them to glide through water, while they use their feet as rudders to steer them.

So whilst penguins don’t use their knees in the traditional sense for walking, they will use them for sliding across the ice, swimming, and incubating their eggs.

Why Do Penguins Waddle?

We all know that penguins walk funny right? They can be seen on nature programmes waddling across the ice, and I have even seen this in Edinburgh zoo. But how is this related directly to the question of do penguins have knees?

The act of walking funny, or waddling, is directly related to the fact that a penguin’s knees are tucked up inside of their body. They are also set quite far back from their body, which makes the act of walking as humans do fairly difficult.

The fact is penguins don’t need to be able to walk like us. In fact waddling is the most effective way for penguins to move around, especially in extremely cold places such as Antarctica.

For a start, penguins don’t really need to worry too much about land predators, especially in Antarctica. They don’t need to run away from them, and certainly don’t attack other land mammals. If you were to see one in the wild you would not need to worry as penguins don’t attack humans.

Penguins don’t need to worry about running away from humans because it is actually illegal to kill, harm or eat penguins! This is due to the signing of a special treaty called the Antarctica treaty, which prevents the harming of penguins and their eggs.

Penguins, unlike most other birds, walk on the soles of their feet rather than their toes. This, combined with the composition of the skeleton and the legs being tucked up inside of their bodies means that waddling is the most efficient form of movement.

Walking in this way saves vital energy, which is needed when living in such harsh, cold conditions. Penguins will only sleep for short amounts of time, minutes rather than hours. They are able to do this standing up, as this also helps to conserve heat energy.

Do Penguins Have Elbows?

Another interesting thing to look at when answering the question do penguins have knees, is if penguins have elbows too. Sounds weird I know, but people do ask this question on the internet.

So do penguins have elbows? Penguins do in fact have elbows. The joints of the elbows and wrists of a penguin are almost fused together, which forms a flat flipper. This flipper is tapered, and is perfect for swimming. A penguin’s flipper can only be moved from the shoulder, and does not bend in the middle.

The bones in a penguins flipper are flatter and broader than in the arms of mammals. The flippers are covered in very short scale-like feathers. These are designed to glide through water when penguins swim.

As well as using their legs and feet, penguins will use their flippers to propel them at high speeds through the water. They don’t use them for anything like catching food on land. All of their food is caught in the water.

Interestingly enough, penguins bury their dead, and after they have used their bills to dig holes, they will use their bills or flippers to push the dead bodies into the ice holes.

Do Penguins Have Ankles?

Another question related to the idea of do penguins have knees is whether or not they have ankles too.

Well do penguins have ankles? Yes penguins do have ankles, which is the case with all birds. They are just different from the ankles of humans and other mammals. In a penguin the ankle joint is known as the tarsometatarsus.

The tarsometatarsus is a fusion between the normal ankle bones (tarsus) found in mammals, and the metatarsal bones of the foot.

Do Penguins Have Hips?

Penguin Swimming Using Knees
This Galapagos penguin skeleton shows their knees are slightly above their hip joints – Thursby16, CC BY-SA 4.0, via Wikimedia Commons

Juts like a penguin has knees, a penguin also has hips too. The hip joint in a bird is usually tucked up near to it’s tail, which is not where you would expect it to be.

With penguins the knees are tucked up near the hips. Neither of these are visible due to being covered by the body. If you look closely at a penguin skeleton, the knees appear to be above the hips.

This gives the appearance that a penguin is permanently crouching. Weird to think that this is what is going on beneath the body of a penguin.

Summing Up

So there you have it. The surprising answer to the question do penguins have knees is a yes. If you look at a penguin skeleton, you will see that their knees are tucked up inside of their body, and are located above where the hip joint is.

Whilst penguins don’t use their knees for walking, they can use them for swimming, sliding on ice, and also for incubating eggs underneath their bodies.

Penguins also have elbows, although they are not the same as the elbows of mammals. They are almost fused together with the wrist joint to make a flipper that is ideal for swimming.

Penguins also have ankles and hips too, although none of these joints is really too similar to the joints of humans and other mammals.

I hope the above information was helpful in answering the question do penguins have knees.

If you have anything to add, or would like to add a question, then please leave a comment below.

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