Leg · Long bone
Fibula (Calf Bone)
The fibula is the thinner of the two lower-leg bones, on the outer side of the calf. It carries little body weight but stabilises the ankle and anchors muscles.
What it is
The fibula is a slender bone running alongside the tibia on the outer side of the lower leg. Its lower end forms the bony bump on the outside of the ankle (the lateral malleolus).
Where it is
The outer (lateral) side of the lower leg, from just below the knee to the outer ankle.
What it does
Provides muscle attachment and stabilises the ankle joint. It bears only a small proportion of body weight, which is why sections can sometimes be used as bone grafts elsewhere.
Connections
Joints and connections
- Ankle joint (outer part)
- Joints with the tibia
When things go wrong
Common injuries and conditions
- Fibula fracture (often with ankle injuries)
- Lateral malleolus (ankle) fracture
Education and reference only. This explains the anatomy in plain terms; it is not a diagnosis. A severe injury, a visibly deformed limb, or the inability to move or bear weight needs urgent assessment — call 999 or go to A&E for a serious injury.
Did you know?
An interesting fact
Because the fibula bears little weight, surgeons can sometimes remove part of it to reconstruct bone elsewhere in the body.
Answers
Fibula: frequently asked questions
What does the fibula do?
The fibula stabilises the ankle and anchors muscles of the lower leg. It carries only a small amount of body weight compared with the tibia.
Can you walk with a broken fibula?
Some fibula fractures allow weight-bearing while others do not, depending on the site and whether the ankle is affected. This must be decided by a clinician after assessment and imaging.
Explore the leg
Related bones
Sources
Where this is drawn from
- NHS — Anatomy and body systems
- Gray's Anatomy for Students (Drake, Vogl, Mitchell)
- TeachMeAnatomy — skeletal system
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