Muscles of Anterior Leg Flashcards
Name the 4 muscles in the anterior compartment of the leg.
Tibialis anterior, extensor digitorum longus, extensor hallucis longus, fibularis tertius
What is the action of the muscles of the anterior leg?
. Dorisflexion and inversion of foot at ankle joint
. Extensor digitorum longus and extensor hallucus longus extend toes
What is the innervation of the anterior leg muscles? What is the spinal root value of this?
Deep fibular nerve (L4-L5)
What is the blood supply of the anterior leg muscles?
Anterior tibial artery
Where is the tibialis anterior located?
On the lateral edge of the tibia
What are the attachments of the tibialis anterior?
Originates from lateral surface of tibia, attaches to medial cuneiform and base of metatarsal 1
What is the action of tibialis anterior?
Dorisflexion and inversion of foot at ankle joint
What is the innervation of the tibialis anterior?
Deep fibular nerve
Where is the extensor digitorum longus?
Lateral and deep to tibialis anterior
What are the attachments of the extensor digitorum longus?
Originates from lateral condyle of tibia and medial surface of fibula, fibres converge into tendon, which travels down dorsal surface of foot, splitting into 4 with each inserting into one of the lateral toes
What does the extensor digitorum longus do?
Dorisflexion and extension of the four lateral toes
What is the innervation of the extensor digitorum longus?
Deep fibular nerve
Where is the extensor hallucis longus located?
Deep to the extensor digitorum longus and tibialis anterior, deep to them both
What are the attachments of the extensor hallucis longus?
Originates from the medial surface of fibular shaft, tendon crosses anterior to ankle joint and attaches to base of distal phalanx of the great toe
What is the action of the extensor hallucis longus?
Dorisflexion of foot, extension of great toe
What is the innervation of the extensor hallucis longus?
Deep fibular nerve
What is ‘special’ about the fibularis tertius muscles?
They aren’t present in all individuals and in some people are considered part of the extensor digitorum longus
What is the action of the fibularis tertius?
Dorisflexion and eversion of the foot
What is the innervation of the fibularis tertius muscles?
Deep fibular nerve
What is footdrop a clinical sign of? How does this most commonly occur and what is the consequence?
. Paralysis of the anterior leg muscles
. Most commonly occurs when there’s damage to the common fibular nerve (from which the deep fibular nerve arises)
. This means the posterior leg muscles are unopposed so there’s unopposed plantarflexion
What are the attachments of the fibularis tertius?
Originates from lower part of extensor digitorum longs, tendon descends with EDL then attaches to metatarsal 5
