Where is the ankle joint located?
The ankle is at the lower end of your leg. It’s where your lower leg meets your foot.
Which type of joint is the ankle?
There are lots of joints and many ways healthcare providers group them together. Joints are usually classified based on:
- Their composition: What they’re made of.
- Their function: How they move.
The ankle is a synovial joint. Synovial joints have the most freedom to move. They’re made of a cavity in one bone that another bone fits into. Slippery hyaline cartilage covers the ends of bones that make up a synovial joint. A synovial membrane — a fluid-filled sac that lubricates and protects the joint — lines the space between the bones. This extra cushioning helps synovial joints move with as little friction as possible.
Functionally, the ankle is a hinge joint. Think about the hinges that hold a door in place. They have a few parts that don’t move, but other pieces move a specific distance to open and close. Your ankle hinges in either direction it can move.
What is the structure of the ankle joint?
Your ankles are made of:
- Bones.
- Cartilage.
- Ligaments.
- Muscles.
- Nerves.
- Blood vessels.
Bones in the ankle
Three bones make up your ankle joint:
Cartilage in the ankle
Cartilage is a strong, flexible tissue that protects your joints. It acts as a shock absorber throughout your body. Your ankle is lined with hyaline cartilage. Hyaline cartilage is the most common type of cartilage in your body. Some healthcare providers call it articular cartilage. It lines your joints and caps the ends of your bones.
Hyaline cartilage is slippery and smooth, which helps your bones move smoothly past each other in your joints. The surfaces of your tibia, fibula and talus that touch each other have a hyaline cartilage lining.
Ligaments in the ankle
Ankle ligaments are like cords that connect bones in your foot to your lower leg bones.
There are three main sets of ligaments in your ankle:
- Medial ligaments (deltoid ligaments): These four ligaments start at the medial malleolus (the bottom end of your tibia). They fan out to connect to the talus, calcaneus (heel bone) and navicular bones in your foot.
- Lateral ligaments: These three ligaments start at the lateral malleolus — the end of the fibula that forms the bump on the outside of your ankle. They connect to the talus and calcaneus.
- Syndesmotic ligaments: These four ligaments connect the tibia and fibula.
Muscles in the ankle
Muscles are soft tissue made of stretchy fibers. They tense up (flex) to pull and move parts of your body. Muscles attached to your legs and feet control your ankle movements.
Muscles that control plantarflexion let you flex your foot down, away from your body. They include the:
- Gastrocnemius.
- Soleus.
- Plantaris.
- Tibialis posterior.
- Flexor digitorum longus.
- Flexor hallucis longus.
- Peroneus brevis.
- Peroneus longus.
Muscles that control dorsiflexion let you move your foot up toward your body. They include the:
- Tibialis anterior.
- Extensor digitorum longus.
- Extensor hallucis longus.
- Peroneus tertius.
Nerves in the ankle
Nerves are like cables that carry electrical impulses between your brain and the rest of your body. These impulses help you feel sensations and move your muscles. Nerves in your ankle include the:
- Tibial nerve.
- Superficial peroneal nerve.
- Deep peroneal nerve.
Blood vessels in the ankle
Blood vessels are channels that carry blood throughout your body. They form a closed loop, like a circuit, that begins and ends at your heart. Three arteries carry blood to and from your ankle, including the:
- Anterior tibial artery.
- Posterior tibial artery.
- Peroneal artery.
