Extensor hallucis longus muscle
Encyclopedia
The Extensor hallucis longus is a thin muscle, situated between the Tibialis anterior and the Extensor digitorum longus that functions to extend the big toe, dorsiflex
Dorsiflexion
Dorsiflexion is the movement which decreases the angle between the dorsum of the foot and the leg, so that the toes are brought closer to the shin. The movement moving in opposite directions is called plantarflexion...

 the foot, and assists with foot inversion
Inversion (kinesiology)
Inversion is the movement of the sole towards the median plane .Tibialis anterior and tibialis posterior invert. Some sources also state that the triceps surae and extensor hallucis longus invert....

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It arises from the anterior surface of the fibula for about the middle two-fourths of its extent, medial to the origin of the Extensor digitorum longus; it also arises from the interosseous membrane to a similar extent.

The anterior tibial vessels and deep peroneal nerve lie between it and the Tibialis anterior.

The fibers pass downward, and end in a tendon
Tendon
A tendon is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments and fasciae as they are all made of collagen except that ligaments join one bone to another bone, and fasciae connect muscles to other...

, which occupies the anterior border of the muscle, passes through a distinct compartment in the cruciate crural ligament
Cruciate crural ligament
The inferior extensor retinaculum of the foot is a Y-shaped band placed in front of the ankle-joint, the stem of the Y being attached laterally to the upper surface of the calcaneus, in front of the depression for the interosseous talocalcanean ligament; it is directed medialward as a double...

, crosses from the lateral to the medial side of the anterior tibial vessels near the bend of the ankle, and is inserted into the base of the distal phalanx
Phalanx bones
In anatomy, phalanx bones are those that form the fingers and toes. In primates such as humans and monkeys, the thumb and big toe have two phalanges, while the other fingers and toes consist of three. Phalanges are classified as long bones.The phalanges do not have individual names...

 of the great toe.

Opposite the metatarsophalangeal articulation
Metatarsophalangeal articulations
The metatarsophalangeal articulations are the joints between the metatarsal bones of the foot and the proximal bones of the toes...

, 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.

Variations

Occasionally united at its origin with the Extensor digitorum longus
Extensor digitorum longus muscle
The Extensor digitorum longus is a pennate muscle, situated at the lateral part of the front of the leg.-Origin and insertion:It arises from the lateral condyle of the tibia; from the upper three-fourths of the anterior surface of the body of the fibula; from the upper part of the interosseous...

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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.

External links

- "The Leg: Muscles"
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