Extensor digitorum brevis muscle


The extensor digitorum brevis muscle is a muscle on the upper surface of the foot that helps extend digits 2 through 4.

Structure

The muscle originates from the forepart of the upper and lateral surface of the calcaneus, from the interosseous talocalcaneal ligament and the stem of the inferior extensor retinaculum. The fibres pass obliquely forwards and medially across the dorsum of the foot and end in four tendons. The medial part of the muscle, also known as extensor hallucis brevis, ends in a tendon which crosses the dorsalis pedis artery and inserts into the dorsal surface of the base of the proximal phalanx of the great toe. The other three tendons insert into the lateral sides of the tendons of extensor digitorum longus for the second, third and fourth toes.

Nerve supply

Nerve supply: lateral terminal branch of Deep Peroneal Nerve . Same innervation of Extensor Hallucis Brevis

Function

Extensor digitorum brevis extends the first four digits at the metatarsophalangeal joint and assists in extending the second, third and fourth digits at the interphalangeal joint. The fifth digit, lacking any insertion from extensor digitorum brevis, can only be raised by the long extensor.

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