Extensor digitorum longus muscle

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Muscle on the lateral part of the front of the leg that extends the toes and dorsiflexes the foot

The extensor digitorum longus muscle is a pennate muscle situated at the lateral part of the front of the leg. It is one of the muscles of the anterior compartment of the leg.

Structure

The extensor digitorum longus muscle originates from the lateral condyle of the tibia, the upper three-fourths of the anterior surface of the fibula, and the upper part of the interosseous membrane. It also arises from the deep surface of the fascia and the intermuscular septa between it and the tibialis anterior muscle and the peroneus longus muscle.

The muscle fibers converge into a tendon which passes under the extensor retinaculum of the foot and divides into four slips. These slips insert into the middle and distal phalanges of the lateral four toes.

Nerve Supply

The extensor digitorum longus muscle is innervated by the deep fibular nerve, which is a branch of the common fibular nerve.

Blood Supply

The blood supply to the extensor digitorum longus muscle is provided by the anterior tibial artery.

Function

The primary function of the extensor digitorum longus muscle is to extend the toes and to assist in the dorsiflexion of the foot at the ankle joint. It plays a crucial role in activities such as walking and running.

Clinical Significance

Injuries or conditions affecting the extensor digitorum longus muscle can lead to difficulties in extending the toes and dorsiflexing the foot. This can result in a condition known as foot drop, where the individual is unable to lift the front part of the foot.

See also

• Extensor hallucis longus muscle
• Flexor digitorum longus muscle
• Anterior compartment of the leg
• Deep fibular nerve
• Anterior tibial artery