Anterior and Lateral Compartment Leg Muscles (Exam/Quiz 3) Flashcards
What are the 4 muscles in the anterior compartment of the leg?
1) tibialis anterior
2) extensor digitorum longus
3) extensor hallucis longus
4) fibularis tertius
There are 4 muscles in the anterior compartment of the leg: tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius. These muscles pass and insert anterior to the transversely oriented axis of the ankle (talocrural) joint and, therefore, are ___________ of the ankle joint, elevating the forefoot and depressing the heel
dorsiflexors (toes go up)
There are 4 muscles in the anterior compartment of the leg: tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius. These muscles pass and insert anterior to the transversely oriented axis of the ankle (talocrural) joint and, therefore, are dorsiflexors of the ankle joint, elevating the forefoot and depressing the heel. The long extensors also pass along and attach to the dorsal aspect of the digits and are thus ____________ of the toes
extensors (elevators)
All of the anterior compartment muscles of the leg are innervated by the….
test q
deep fibular n.
All of the lateral compartment muscles of the leg are innervated by the….
test q
superficial fibular n.
What are the 2 muscles of the lateral compartment of the leg?
1) fibularis longus
2) fibularis brevis
What is the origin/proximal attachment for the tibialis anterior?
lateral condyle and superior half of lateral surface of tibia and interosseous membrane
What is the insertion/distal attachment of the tibialis anterior?
medial and inferior surfaces of the medial cuneiform and base of the 1st metatarsal
What innervates the tibialis anterior?
deep fibular n.
What are the actions of the tibialis anterior?
-dorsiflexes ankle and inverts foot
-active in controlling forefoot to the ground during heel strike
What is the origin/proximal attachment for the extensor digitorum longus?
lateral condyle of tibia and superior 3/4 of medial surface of fibula and interosseous membrane
What is the insertion/distal attachment for the extensor digitorum longus?
middle and distal phalanges of lateral 4 digits
What innervates the extensor digitorum longus?
deep fibular n.
What are the actions of the extensor digitorum longus?
extends lateral 4 digits and dorsiflexes the ankle
What is the origin/proximal attachment for the extensor hallucis longus?
middle part of anterior surface of the fibula and interosseous membrane
What is the insertion/distal attachment for the extensor hallucis longus?
dorsal aspect of base of distal phalanx of great toe/hallux
What innervates the extensor hallucis longus?
deep fibular n.
What are the actions of the extensor hallucis longus?
extends great toe and dorsiflexes the ankle
What is the origin/proximal attachment for the fibularis tertius?
inferior 3rd of anterior surface of fibula and interosseous membrane
What is the insertion/distal attachment for the fibularis tertius?
dorsum of base of 5th metatarsal
What innervates the fibularis tertius?
deep fibular n.
What are the actions of the fibularis tertius?
test q
-dorsiflexes ankle and aids in eversion of the foot
-contracts reflexively where it senses sudden inversion to protect the tibiofibular ligament (the most commonly sprained ligament in the body)
What is the most commonly sprained ligament in the body?
tibiofibular ligament
What is the origin/proximal attachment for the fibularis longus?
test q
head and superior 2/3 of lateral surface of fibula
What is the insertion/distal attachment of the fibularis longus?
test q
base of 1st metatarsal and medial cuneiform
What innervates the fibularis longus?
test q
superficial fibular n.
What are the actions of the fibularis longus AND brevis?
test q
everts foot and weakly plantar flexes ankle
What is the origin/proximal attachment for the fibularis brevis?
test q
inferior 2/3 of lateral surface of the fibula
What is the insertion/distal attachment for the fibularis brevis?
test q
dorsal surface of tuberosity on lateral side of base of 5th metatarsal
What innervates the fibularis brevis?
test q
superficial fibular n.