Fibularis brevis muscle

Last revised by Yahya Baba on 6 Feb 2023

The fibularis brevis muscle, also known as the peroneus brevis muscle, is a muscle in the lateral compartment of the leg. It lies deep/medial to the adjacent fibularis longus, and is a shorter and smaller muscle. Both brevis and longus travel together along the lateral aspect of the ankle within a shared synovial sheath 4. Together the tendons wrap around the lateral malleolus, specifically within the retromalleolar groove of the distal fibula.

At the level of the retromalleolar groove, the fibularis brevis tendon is located more anteromedial to the larger/rounder fibularis longus tendon. This can be remembered using the memory aid: "brevis closer to bone" (closer to the bones of the ankle, anteromedial to the peroneus longus tendon).

  • lower two thirds of the lateral shaft of the fibula

  • the fibularis brevis tendon passes down the leg deep to the fibularis longus muscle, and curves around the lateral malleolus creating the retromalleolar groove

  • both fibular tendons then course anteriorly toward the fibular trochlea of the lateral calcaneum, at which point the tendon of brevis runs superior to the trochlea before terminating at the tubercle of the base of the fifth metatarsal

  • fibular artery

  • superficial peroneal nerve (L5, S1)

  • everts foot and weakly plantarflexes it

  • provides support for the lateral longitudinal arch

  • tibialis anterior

  • duplex belly fibularis brevis

  • fusion of fibularis brevis and fibularis longus

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