It looks like chickens are just walking on chopsticks. And if you look at other birds, it seems their knees are bending backward. So, how are chickens moving, jumping, and roosting?
Do Chickens Have Knees?
Yes, chickens have knees and kneecaps. They are well hidden behind their feathers. Chickens walk on their toes rather than on their foot. The sticks you see are their actual feet, and the joint is their ankle. Their knees point forward but are hidden behind their feathers.
Anatomically, the chicken’s leg has roughly the same body parts as ours:
- toes: chickens walk on their toes all day. Most chickens have four toes, three pointing forward and one pointing backward
- feet: what most people call the legs are actually the feet of the chicken, anatomically speaking
- ankle: the joint that you can see is the ankle, and not the knee
- tibia: the shinbone in humans is called the tibia. If you are eating a chicken, this bone holds the meat of the drumstick
- thigh: the bone in the thigh of the chicken is the femur
Most people think the knee is where they see the legs of the chicken bend. But that’s actually the ankle and the heel.
The joint between the tibia (shinbone) and the femur (tight) is the real knee of a chicken. When you go all the way to the end of the thigh, the femur ends in the chicken’s hip.
You might hear people saying their chickens lost a foot due to toe injuries or frostbite. These chickens actually lost their toes. Sometimes they will learn to walk on their ‘real feet’ by using their ankles and knees to hop around.
In the end, the skeleton of a chicken’s leg is quite similar to our legs. The main difference is that the chicken’s legs aren’t as straight as ours and covered in feathers.
Do chicken’s knees bend backward?
No, the chicken’s knees bend forward. The visible joint in the chicken leg pointing backward is the anatomical ankle of the chicken leg. A chicken’s knee is pointing forward but is invisible behind its feathers. This bend is the same as in other birds. This also allows them to walk backward.
The fact that a chicken has ankles bending backward and knees bending forward gives them a lot of stability. They can balance exceptionally well on their legs. When chickens are roosting, they sit on roosting bars, keeping themselves balanced. Sleeping on a small bar might seem magical as they pretend to be sitting on chopsticks. But the truth is that they are just hiding most of their legs and muscles under their feathers.
Connected from thigh to toe
The muscles that connect all parts of the legs form a complete system altogether. When a chicken sits, the ankle and knee joints are bent, automatically closing the bird’s toes. This mechanism is less pronounced in chickens compared to other birds. Chickens are no parrots that can swing upside down with a death grip.
Do Chickens have Kneecaps?
Yes, chickens have kneecaps, also called patellas. The kneecap sits on top of the chicken’s knee, connected with tendons to their tibia (shinbone) and femur (thigh). Their kneecap increases the chicken’s power when extending their legs to jump.
The power boost comes from the lever effect. By having the tendons connected to the kneecaps, the angle increases along with the leverage. The thighs of chickens consist of multiple muscle groups but roughly correspond to our human quadriceps.
Eating Chicken Knees in Asia
In Asia, you find places where you can order chicken kneecaps from the menu. It’s not that they are preparing tiny bones to eat, but they prepare the articular cartilage that’s connected to the lower legs and thigh.
Most people won’t eat these parts of a chicken, but chefs are turning them into crispy fried nuggets in Asia.
Is a chicken’s knee the same as our elbow?
No, a chicken’s knee is similar to a human knee, not an elbow. The knees are part of the leg of the chicken, connecting the upper thighs to the legs. They are hidden behind their feathers. The elbows of a chicken are part of their wings, connecting the humerus and radius bones.
What are the differences between chicken’s knees and human knees?
The chicken’s knees are surprisingly similar compared to human knees.
But they are birds, after all, so there are some differences:
- bone length: a chicken’s thigh bone (femur) is much shorter than its shinbone (tibia). This allows them to jump and stabilize when they are roosting.
- lower leg and foot: the lower part of their leg (tibia) is fused with parts of their feet (tarsal bones). So that’s why it’s scientifically referred to as the tibiotarsus in chickens (tibia + tarsal bones).
- stabilizing muscle: we humans have a muscle that crosses our knee called the popliteus muscle. It allows us to rotate our lower leg whenever it’s not in contact with the ground. Chickens don’t have that muscle. For humans, it’s an important stabilizer and locking mechanism of the knee for walking, but that’s because we are walking in an upright position.
- independent toes: we humans can flex our toes independently from the muscles in the rest of our legs. We use the soles of our feet to walk on the ground with some load on our knees. But in chickens, the muscle attached to the toes starts at the thigh bone (femur) and acts as an extensor for the knee, foot, and toes. The human version of this muscle, the extensor digitorum longus, is only attached to the lower leg.
Of course, there are plenty of other minor differences, but in the end, the hind limbs of a chicken aren’t that different from ours. The main difference is that humans have some extra features for stability and freedom of the knees to enable us to walk in an upright position.
Chickens have fully functional knees and kneecaps, just like humans. Most people confuse chicken’s knees and ankles as their knees are hidden behind their feathers. The visible joints are their ankles, and chickens are actually walking on their toes all the time.