Fibula: Definition and What it is

Medically and clinically reviewed by Jonathan Lee, MD and Dylan Peterson, PT, DPT

Fibula Definition and Meaning

The fibula, also known as the calf bone, is a long, slender bone located in the lower leg that runs parallel to the tibia from the knee to the ankle. The fibula plays a crucial role in supporting the muscles of the lower leg and stabilizing the ankle in order to help facilitate essential movements like walking, running, and jumping.

Anatomy of the Fibula

At the upper end of the fibula near the knee is the fibular head (or proximal aspect), which connects to the tibia and facilitates movements of the knee joint. The central part of the fibula, the fibula shaft, plays a significant role in forming the structure of the calf. The lower segment, known as the distal fibula, connects to the tibia and bones of the ankle and foot, supporting the stability and function of the ankle joint.

Function of the Fibula

The fibula is crucial for the structure and stability of the lower leg. It forms the structure of the calf and the outer lower leg, supports the ankle, and contributes to the stability of knee ligaments. The fibula also supports various muscles, tendons, nerves, and ligaments in the leg and ankle, playing a vital role in mobility and balance.

Common fibula-related injuries include: ankle sprains, as the result of sudden ankle twisting leading to pain, swelling, and instability up the leg; shin splints, which cause pain in the lower leg primarily affecting the tibia but can also involve fibular pain; osteoarthritis at the ankle joint which can impact the fibula and result in chronic pain and limited mobility over time; peroneal tendinitis, which occurs when the peroneal tendon in the ankle (which runs along the outside of the fibula) becomes inflamed; and fibular stress fractures, which are small cracks in the fibula and are more common among athletes.

Fibula Pain: A Hinge Health Perspective

The fibula is very resilient and designed to recover from the kinds of issues that naturally can happen in the course of everyday activities or during exercise.

If you’re reluctant to move because you think you’ll cause more damage or injury to your lower leg, know this: Movement is often the fastest way to healing. As our Hinge Health care team says, movement is medicine. Movement helps rehab the fibular muscles, tendons, and ligaments by increasing blood flow and gradually improving the lower leg’s strength and flexibility.

Physical therapy can aid in the treatment and recovery of many fibula-related conditions. A physical therapist (PT) can show you specific stretching and strengthening exercises for your lower leg that may help your calves and ankles feel better by restoring strength, flexibility, and range of motion. You can see a physical therapist in person or use a program like Hinge Health to access a PT via telehealth/video visit.

How Hinge Health Can Help You 

If you have joint or muscle pain that makes it hard to move, you can get the relief you’ve been looking for with Hinge Health’s online exercise therapy program.

The best part: You don’t have to leave your home because our program is digital. That means you can easily get the care you need through our app, when and where it works for you. 

Through our program, you’ll have access to therapeutic exercises and stretches for your condition. 

Additionally, you’ll have a personal care team to guide, support, and tailor our program to you. See if you qualify for Hinge Health and confirm free coverage through your employer or benefit plan here.

This article and its contents are provided for educational and informational purposes only and do not constitute medical advice or professional services specific to you or your medical condition.


  1. Gupton, M., Munjal, A., & Kang, M. (2020). Anatomy, Bony Pelvis and Lower Limb: Fibula. PubMed; StatPearls Publishing. 

  2. Fibula. (n.d.). Physiopedia. Retrieved from

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