17: Anterior And Lateral Leg Flashcards
Two functions of the anterior leg
Dorsiflexion, toe extension
Four muscles of anterior leg
- Tibialis anterior
- Extensor hallucis longus
- Extensor digitorum longus
- Fibularis tertius
Tibialis anterior O and I
O: lateral tibial condyle
I: medial surface of 1st cuneiform, first metatarsal
Tibialis anterior A
Dorsiflexion, foot inversion
Extensor hallucis longus O and I
O: anteromedial fibula, interosseous membrane
I: distal phalanx of hallux
Extensor hallucis longus A
Extend hallux, dorsiflexion
Extensor digitorum longus O and I
O: lateral tibial condyle, anterior fibular surface, interosseous membrane
I: forms an extensor expansion over dorsum of lateral four proximal phalanges
Slips of extensor expansion of extensor digitorum longus
Two lateral slips over the distal phalanx + one central slip over the middle phalanx
Extensor digitorum longus A
Extend lateral four digits, dorsiflexion
Fibular tertius presence
Variable; fused with digitorum longus proximally
Difference between fibularis tertius and the fibularis muscles
Fibularis tertius: tendon runs anterior to lateral malleolus
Fibularis muscles: tendon runs posterior to lateral malleolus
Fibular tertius O and I
O: anteroinferior fibula
I: dorsum of fifth metatarsal
Fibularis tertius A
Dorsiflexion, eversion
Shin splints
Mild form of compartment syndrome due to repetitive microtrauma to tibialis anterior -> small tears in periosteum of tibia/deep fascia
Innervation to anterior leg
Deep fibular N
Blood supply to anterior leg
Anterior tibial A
What does the deep fibular N run with?
Anterior tibial A and V
Terminal branches of the deep fibular N
Medial and lateral terminal branches on dorsum of foot
What does the deep fibular N supply?
Anterior compartment, ankle joint, metacarpal-phalange joints, dorsal intrinsic foot muscles, skin between 1st and 2nd digits
Where does anterior tibial A come from?
Popliteal A
Where does the anterior tibial A begin?
Inferior border of popliteus, near tibial tuberosity
Anterior tibial A path
Runs anterior on the interosseous membrane, between EHL and TA muscles
Termination of anterior tibial A
Dorsalis pedis A (at ankle)
Two muscles in lateral leg
Fibularis longus, fibularis brevis
Which lateral leg muscle is more superficial?
Fibularis longus
Fibularis longus O and I
O: head/superolateral fibula
I: first metatarsal, medial cuneiform
Fibularis longus path
Runs just posterior to lateral malleolus, obliquely across sole of the foot
Fibularis longus and brevis action
Eversion, plantarflexion
Fibularis brevis O and I
O: inferolateral 2/3 of tibia
I: dorsal/lateral side of fifth metatarsal
Innervation to lateral compartment of leg
Superficial fibular N
Where does the superficial fibular N become superficial
In the distal third of the leg
Superficial fibular N supplies?
Anteroinferior leg, nearly entire dorsal surface of foot/toes
Blood supply to lateral leg (no distinct artery accompanying this compartment)
Fibular A branches
What is the largest branch of the posterior tibial A
Fibular A
