Anterior Compartment Muscles Flashcards
How can you test the power of Tib. Ant?
Ask the patent to stand on their heels. It is the greatest dorsiflexor of the foot
Name the muscles of the anterior compartment along with their function and nerve and artery supply.
Tibialis anterior, extensors digitorum longus/ hallucis longus and peroneus tertius.
Dorsiflex and invert foot at ankle joint.
EHL and EDL also extend the toes.
Innervate by deep peroneal nerve.
Blood supplied by anterior tibial artery.
Name origin, insertion and action of Tib Ant?
Originates lateral surface of tibia.
Inserts medial cuneiform and base of 1st. (Dorsal)
Dorsiflexion and inversion of the foot.
Name origin, insertion and action of Extensor digitorum longus?
Lateral condyle of tibia and medial surface of fibula.
The fibres converge into a tendon which travels to the dorsal surface of the foot.
The tendon then splits into 4, each inserting onto a toe.
Extension of the lateral 4 toes and dorsiflexion of the foot.
Name origin, insertion and action of Extensor hallucis longus?
The EHL is deep to TA and EDL.
Originates Medial surface of the fibular shaft.
The tendon crosses anterior to the ankle joint and inserts into distal phalanx of hallux.
Extension of hallux and dorsiflexion of foot.
Name origin, insertion and action of Peroneus tertius?
Originates lower anterior surface fibula.
Inserts dorsal aspect base of 5th metatarsal.
Weak dorsiflexor of the foot and EVERTS the foot at ankle joint.
What do some believe about peroneus tertius?
Since it arises from most inferior part of EDL and it is not present in all individuals that it is indeed part of EDL.
What is the clinical condition which arises as a result of damage to the common peroneal nerve?
Foot drop.
Foot drop is a clinical sign indicating paralysis of which muscles?
The anterior compartment muscles are paralysed.
Describe what happens when these muscles are paralysed?
The unopposed pull of the plantarflexor muscles (posterior compartment) produces permanent plantarflexion.
How will a patient with foot drop walk?
The affected limb will drag along the ground. In order to circumvent this the patient can flick the foot outwards while walking - known as eversion flick.
