Peroneus Tertius - Muscle Physiology & Functional Anatomy


Peroneus Tertius Muscle




  • Distal (third quarter) of anterior shaft of fibula


  • Dorsal surface (shaft & base) of 5th metatarsal

Major Arteries:

  • Deep fibular nerve


Neural Innervation:

  • Deep peroneal nerve (L5,S1)


Trigger Points: 

Trigger points for the peroneus Tertius




Concentric Functions:

  • Dorsiflexion (weak) & eversion (pronation) of the foot

Eccentric Functions:

  • Decelerates ankle plantar flexion

Isometric Function:

  • Helps stabilize the foot & ankle complex

Related Muscles





More Images of the Peroneus Tertius Muscle

Peroneus Tertius

More Information about the Peroneus Tertius Muscle

The peroneus tertius muscle also referred to as the fibularis tertius is one of the three peroneal muscles of the lower leg & foot along with the peroneus longus & brevis. 

Unlike the peroneus brevis & longus which are part of the lateral compartment of the leg, the peroneus tertius is in the anterior compartment of the leg.  It is innervated by the deep peroneal nerve rather than the superficial peroneal nerve.


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