The extensor digitorum brevis muscle (sometimes EDB) is a
muscle
Skeletal muscles (commonly referred to as muscles) are Organ (biology), organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other ...
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
In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock.
...
(in front of the groove for the
peroneus brevis
In human anatomy, the fibularis brevis (or peroneus brevis) is a muscle that lies underneath the fibularis longus within the lateral compartment of the leg. It acts to tilt the sole of the foot away from the midline of the body (eversion) and to ...
tendon), from the
interosseous talocalcaneal ligament
The interosseous talocalcaneal ligament forms the chief bond of union between the talus and calcaneus.
It is a portion of the united capsules of the talocalcaneonavicular and the talocalcaneal joints, and consists of two partially united layers ...
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
The extensor hallucis brevis is a muscle on the top of the foot that helps to extend the big toe.
Structure
The extensor hallucis brevis is essentially the medial part of the extensor digitorum brevis muscle. Some anatomists have debated wheth ...
, 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
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-quarters of the anterior surface of the body of ...
for the second, third and fourth toes.
Nerve supply
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
Spinal disc herniation is an injury to the cushioning and connective tissue between vertebrae, usually caused by excessive strain or trauma to the spine. It may result in back pain, pain or sensation in different parts of the body, and physica ...
causing L5 lesion). Same innervation of
Extensor Hallucis Brevis
The extensor hallucis brevis is a muscle on the top of the foot that helps to extend the big toe.
Structure
The extensor hallucis brevis is essentially the medial part of the extensor digitorum brevis muscle. Some anatomists have debated wheth ...
Function
Extensor digitorum brevis extends the first four digits at the
metatarsophalangeal joint
The metatarsophalangeal joints (MTP joints), also informally known as toe knuckles, are the joints between the metatarsal bones of the foot and the proximal bones ( proximal phalanges) of the toes. They are condyloid joints, meaning that an el ...
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.
Additional images
File:Gray268.png, Bones of the right foot. Dorsal surface.
File:Gray437.png, Muscles of the front of the leg.
File:Gray440_color.png, Cross-section through middle of leg.
File:Slide1ABBAA.JPG, Dorsum of Foot. Deep dissection.
File:Slide2ABBAA.JPG, Dorsum of Foot. Deep dissection.
See also
*
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-quarters of the anterior surface of the body of ...
*
Extensor hallucis brevis
The extensor hallucis brevis is a muscle on the top of the foot that helps to extend the big toe.
Structure
The extensor hallucis brevis is essentially the medial part of the extensor digitorum brevis muscle. Some anatomists have debated wheth ...
*
Extensor digitorum muscle
The extensor digitorum muscle (also known as extensor digitorum communis) is a muscle of the posterior forearm present in humans and other animals. It extends the medial four digits of the hand. Extensor digitorum is innervated by the posterior int ...
External links
* - "The Foot: Muscles"
*
PTCentral
{{Authority control
Calf muscles
Muscles of the lower limb