Fibula: anatomy, landmarks and muscle attachments
The fibula is the thin lateral bone of the leg. Learn its head, neck and lateral malleolus, its role in the ankle joint and the many muscles that attach to it, from biceps femoris to soleus.
Quick answer
- Latin name
- Fibula
- Type
- Long bone
- Location
- Lateral side of the leg, from below the knee to the ankle
- Joints
- Proximal and distal tibiofibular joints with the tibia; ankle joint with the talus (through the lateral malleolus)
- Main landmarks
- Head, neck, shaft, lateral malleolus
The fibula is the slender bone on the outer side of the leg. It carries very little of the body's weight, but it anchors many muscles and forms the outer wall of the ankle joint.
Upper end
- The head sits just below the knee, on the outer side, but it isn't part of the knee joint: it articulates with the tibia. The biceps femoris and the lateral collateral ligament attach there.
- The common fibular nerve wraps around its neck, just under the skin, which makes it vulnerable to pressure or injury.
Shaft
The thin shaft is wrapped in muscles: the fibular (peroneal) muscles on the outside, the extensors in front and the soleus and deep flexors behind.
Lower end
The lateral malleolus is the bump on the outer side of the ankle. It reaches lower than the medial malleolus of the tibia, and the two together grip the talus to form the ankle joint.
Frequently asked questions
Does the fibula bear weight?
Very little. The tibia carries most of the body's weight; the fibula mainly anchors muscles and stabilises the ankle.
Is the fibula part of the knee joint?
No. Its head articulates with the tibia below the knee joint.
What is the lateral malleolus?
The bony prominence on the outer side of the ankle, at the lower end of the fibula.