Extensor digitorum brevis

Extensor digitorum brevis muscle
The mucous sheaths of the tendons around the ankle. Lateral aspect. (Extensor dig. brevis labeled at upper right.)
Details
Origin	Dorsal surface of calcaneus
Insertion	Proximal dorsal region of middle phalanges 2, 3 and 4
Artery	Dorsalis pedis artery
Nerve	Deep fibular nerve
Actions	Extends digits 2 through 4
Antagonist	Flexor digitorum longus, Flexor digitorum brevis
Identifiers
Latin	Musculus extensor digitorum brevis
Dorlands /Elsevier	m_22/12548900
TA	A04.7.02.055
FMA	51140
Anatomical terms of muscle []

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

Origin: forepart of upper and lateral surface of calcaneus, in front of groove for peroneus brevis, from interosseous talocalcaneal ligament, stem of inferior extensor retinaculum.

Course: fibres pass obliquely forwards and medially cross dorsum of foot and end in four tendons. The medial part of muscle ends in tendon which crosses the dorsalis pedis artery, inserts into dorsal surface base of PPX of great toe and is termed extensor hallucis brevis. The other three tendons insert into lateral sides of tendon of extensor digitorum longus which insert into the 2nd, 3rd and 4th toes.

Nerve supply: lateral terminal branch of Deep Peroneal Nerve (deep fibular nerve) (proximal sciatic branches L4-L5, but most clinically relevant L5 with L4/L5 spinal disc herniation causing L5 lesion). Same innervation of Extensor Hallucis Brevis

Action: extends MTP of 1st to 4th digits and assists in extending the IP joints of 2nd, 3rd, and 4th digits.

Note: without EDL there is no extension of 5th digit.

Bones of the right foot. Dorsal surface.

Muscles of the front of the leg.

Cross-section through middle of leg.

Dorsum of Foot. Deep dissection.

Dorsum of Foot. Deep dissection.