Week 5 - ankle Flashcards
anterior compartment of the leg
anterior side between lateral surface of tibia, medial surface of fibula, anterior aspect of interosseous membrane
anterior compartment 4 muscles
tibialis anterior
extensor hallucis longus
extensor digitorium longus
peroneus tertius
anterior compartment actions
ankle dorsiflexion
foot inversion
toe extension
anterior compartment - nerve supply
deep peroneal nerve
anterior compartment - blood supply
anterior tibial artery
runs through the lateral compartment travels with the nerve
tibialis anterior
origin: upper 2/3 of lateral surface of tibial and adjacent interosseous membrane
insertion: medial and inferior surface of the medial cuneiform and 1st metatarsal
nerve: deep peroneal
root: L4-L5
extensor hallucis longus
origin: middle 1/2 of medial surface of fibula and adjacent interosseous membrane
insert: dorsal aspect of base of distal phalanx on greater toe
nerve: deep peroneal nerve
root L5-S1
extensor digitorum longus
origin: upper 1/2 of medial surface of fibula and adjacent interosseous membrane
insert: via extensor expansion onto the dorsal surface of the bases of middle and distal phalanges 2-5
nerve: deep peroneal
root: L5-S1
peroneus tertius
origin: lower 1/3 medial surface of fibula and adjacent interosseous membrane
insert: medial and dorsal aspect of the base on 5th metatarsal
nerve: deep peroneal
root: L5-S1
extensor retinacula
hold the anterior compartment tendon in place at the front of ankle
two strong fascial band: superior extensor retinaculum and inferior extensor retinaculum
tibialis anterior action
ankle dorsiflexion and foot inversion
maintains medial arch by supinating the foot with foot flexed
controls lowering foot when walk/run
extensor hallucis and digitorum longus action
dorsiflex and toe extension
peroneus teritus action
weak dorsi flex and week foot eversion
motor supply in foot (2)
dorsum of foot:
extensor digitorum brevis and extensor hallucis brevis
