Extensor hallucis longus muscle

Template:Short description Template:Refimprove Template:Infobox muscle The extensor hallucis longus muscle is a thin skeletal muscle, situated between the tibialis anterior and the extensor digitorum longus. It extends the big toe and dorsiflects the foot. It also assists with foot eversion and inversion.

Structure

The muscle ends as a tendon of insertion. The tendon passes through a distinct compartment in the inferior extensor retinaculum of foot. It crosses anterior tibial vessels lateromedially near the bend of the ankle.Template:Citation needed In the foot, its tendon is situated at along the medial side of the dorsum of the foot.<ref name=":0223">Template:Cite book</ref> Opposite the metatarsophalangeal articulation, the tendon gives off a thin prolongation on either side, to cover the surface of the joint. An expansion from the medial side of the tendon is usually inserted into the base of the proximal phalanx.Template:Citation needed

Origin

The extensor hallucis longus muscle arises from the middle portion of<ref name=":02">Template:Cite book</ref> the anterior surfaceTemplate:Citation needed of the fibula and adjacent interosseous membrane of the leg.<ref name=":022">Template:Cite book</ref> Its origin is medial to the origin of the extensor digitorum longus muscle.Template:Citation needed

Insertion

The muscle inserts at the base of the distal phalanx of the great toe.<ref name=":0222">Template:Cite book</ref>

Nerve supply

The muscle receives motor innervation from the deep fibular nerve (L5)<ref name=":022" /> (a branch of common fibular nerve).

Relations

The anterior tibial vessels and deep fibular nerve pass between this muscle and the tibialis anterior muscle.

Variation

Occasionally united at its origin with the extensor digitorum longus.

The extensor ossis metatarsi hallucis, a small muscle, sometimes found as a slip from the extensor hallucis longus, or from the tibialis anterior, or from the extensor digitorum longus, or as a distinct muscle; it traverses the same compartment of the transverse ligament with the extensor hallucis longus.

Actions/movements

The muscle extends/dorsiflects the big toe (primary action), and dorsiflects the foot (secondary action).<ref name=":022" />

Additional Images

• Gray440 color.png

  Cross-section through middle of leg. (Extensores longi digitorum et hallucis labeled at upper left.)

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  Dorsum of Foot. Deep dissection.

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  Dorsum of Foot. Deep dissection.

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  Ankle joint. Deep dissection. Medial view

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  Ankle joint. Deep dissection. Lateral view.

References

Template:Gray's <references />

External links

• Template:SUNYAnatomyLabs - "The Leg: Muscles"
• University of Washington