Peroneus Tertius

Description[edit | edit source]

Fibularis tertius muscle

The Peroneus Tertius muscle, also called Fibularis Tertius, is one of the 3 fibularis muscles (fibularis longus, Fibularis Brevis).[1] It is the most superficial muscle in the anterior compartment of leg. Other muscles in the anterior compartment include tibialis anterior, extensor hallucis longus and Extensor Digitorum Longus[2]

The muscle's presence varies depending on the population studied. Prevalence in different populations has been reported to be the following[3]:

  • Asian populations: 38.5%-95.5%
  • West Asian populations: 38.5%-42%
  • India: 87-90%
  • China: 89.3%
  • Japan: 95.5%
  • Egypt: 52.8%
  • Tunisia: 67.7%
  • Chile: 49.1%
  • Brazil: 93.8%
  • Bolivia: 100%
  • Spain: 38.2%
  • Belgium: 81.5%
  • Britain: 92.7%
  • France: 90.9%
  • Austria: 92.9%
  • Poland: 85.8%

Anatomy[edit | edit source]

Origin[edit | edit source]

Distal half or third of the fibula[4]

Intermuscular septum[3]

Insertion[edit | edit source]

Before reaching it's insertion, the tendon passes under the extensor retinaculum of the foot with the Extensor Digitorum Longus tendon[3].

Dorsal surface of the base of the 5th metatarsal[4]

[5]

Nerve[edit | edit source]

Deep peroneal nerve[1]

Artery[edit | edit source]

Anterior tibial artery[2]

Function[edit | edit source]

  • Assists with foot dorsiflexion and eversion[4]
  • Works with extensor digitorum longus during swing phase of gait[3]

Clinical relevance[edit | edit source]

The strength of eversion and dorsiflexion is not compromised in people who lack the Fibularis Tertius muscle. Fibularis Tertius seems to not provide higher protection against ankle ligamentous injury.[6]

Fibularis Tertius Syndrome is a condition characterized by catching, clicking, locking or popping of peroneus tertius tendon over ankle during walking. It is a rare condition of anterolateral ankle pain or rear foot pain. This could be secondary to impingement and constriction of peroneus tertius in the extensor retinaculum.[2]

Fibularis tertius may be affected when a person has anterior compartment syndrome.[2]

The tendon may be used by surgeons as a donor for tendon transfer or tendoplasty procedures[3].

Assessment[edit | edit source]

Active motion or resisted motion for manual muscle testing involves combined ankle dorsiflexion and eversion.

[7]

References[edit | edit source]

  1. 1.0 1.1 Lippert, Lynn S. Clinical Kinesiology and Anatomy. 5th ed. Philadelphia: F A Davis Company; 2016.
  2. 2.0 2.1 2.2 2.3 Chaurasia BD. Human Anatomy Regional and Applied Dissection and Clinical. Vol 2. CBS Publishers and Distributors Pvt Ltd, 2010
  3. 3.0 3.1 3.2 3.3 3.4 Olewnik Ł. Fibularis Tertius: Anatomical Study and Review of the Literature. Clin Anat. 2019 Nov;32(8):1082-1093.
  4. 4.0 4.1 4.2 Witvrouw E, Vanden Borre K, Willems TM, Huysmans J, Broos E, De Clercq D. The significance of peroneus tertius muscle in ankle injuries: a prospective study. The American journal of sports medicine. 2006 Jul;34(7):1159-63.
  5. Nabil Ebraheim. Peroneus Tertius Muscle- Everything You Need To Know-Dr.Nabil Ebraheim Available from:https://www.youtube.com/watch?v=n6XWHKJg2OY [last accessed 11/05/2020]
  6. Witvrouw E, Vanden Borre K, Willems TM, Huysmans J, Broos E, De Clercq D. The significance of peroneus tertius muscle in ankle injuries: a prospective study. The American journal of sports medicine. 2006 Jul;34(7):1159-63.
  7. Ashley Reed. Peroneus Longus, Brevis, & Tertius - Reisch. Available from: https://www.youtube.com/watch?v=DDGDaKAmbc8 [last accessed 23/3/2022]