What muscles are found on the dorsum of the foot?

The dorsum includes extrinsic tendons from anterior leg muscles (tibialis anterior, extensor hallucis longus, extensor digitorum longus, peroneus tertius) and one intrinsic muscle: the extensor digitorum brevis.

What is the extensor digitorum brevis, and where is it located?

It's the only intrinsic muscle on the dorsum, often appearing as a soft swelling anterior to the lateral malleolus. It originates from the calcaneus and inserts via tendons to the toes.

What are the actions of the extensor digitorum brevis?

Its actions include the extensor hallucis brevis portion extending the big toe's metatarsophalangeal joint, and the lateral tendons extending the MP and IP joints of the 2nd, 3rd, and 4th toes, especially during dorsiflexion.

How is the extensor digitorum brevis innervated?

It is supplied by the lateral terminal branch of the deep peroneal nerve.

What is the difference between extensor digitorum brevis and extensor hallucis brevis?

Extensor hallucis brevis is the medial-most portion of the extensor digitorum brevis, specifically acting on the great toe. It is functionally and developmentally distinct but part of the same muscle.

Why might the extensor digitorum brevis be mistaken for an injury?

Due to its soft, fleshy swelling anterior to the lateral malleolus, it can resemble a contusion or other trauma in clinical examination.

What related structures are important for the dorsum of the foot?

Key related topics include the deep peroneal nerve for innervation, the dorsalis pedis artery (crossed by the extensor hallucis brevis tendon), and surface anatomy of the area.

Dorsum Foot Muscles – Extensor Digitorum Brevis

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