Ch. 22 Musculature of Leg and Dorsum of Foot Flashcards
Tibialis Anterior
O : Lateral surface of tibia and interosseous membrane
I: medial cuneiform and base of first metatarsal
A: Dorsiflexes and inverts foot
N: Deep fibular n.
Extensor Digitorum Longus
O: anterior surface of fibula and interosseous membrane
I: middle and distal phalanges of four toes
A: extends toes and dorsiflexes foot
N: Deep fibular n.
Fibularis (peroneus) tertius
O: distal anterior surface of fibula (lateral)
I: base of fifth metatarsal
A: aids in eversion and dorsiflexion
N: deep fibular n.
Extensor Hallucis Longus
O: mid-portion of fibula, deep to tibialis anterior and extensor digitorum longus
I: base of distal phalanx of great toe (hallux)
A: extends great toe , and dorsiflexes foot
N: deep fibular n.
Extensor Digitorum Brevis
O: dorsal surface of calcaneus
I: base of proximal phlanx of great toe, and proximal phalanges 2,3,4 via tendons of the extensor digitorum longus
A: extends toes 1,2,3,4
N: Deep fibular n.
Fibularis longus
O: upper lateral fibula
I: posterior of first metatarsal and medial cuneiform
A: everts and plantar flexes foot
N: superficial fibular n.
Fibularis brevis
O: distal lateral fibula
I: base of fifth metatarsal
A: everts and plantar flexes foot
N: superficial fibular n.
Gastroscnemius
- important for running and walking
O: posterior surface of lateral and medial femoral condyles
I: Calcaneus (along with soleus and plantaris)
A: Plantar flexes foot, flexes the leg
N: Tibial n.
Soleus
thick, multipennate, strong
O: posterior surface of head and proximal shaft of fibula, soleal line on upper part of tibia
I: calcaneus (with gastrocnemius and plantaris muscles)
A: plantar flexes foot
N: tibial n.
Plantaris
“freshman nerve” - accesory muscle
O: posterior surface of lateral femoral condyle of fibula
I: calcaneus (w/ soleus and gastrocnemius)
A: weakly plantar flexes foot and flexes leg
N: Tibial n.
Popliteus
“unlocking mechanism”
O: lateral surface of lateral condyle of femur
I: proximal tibia above soleal line
A: flexes and medially rotates leg; when foot is fixed, laterally rotates femur and unlocks knee joint as leg flexion proceeds
N: Tibial n.
Flexor Digitorum longus
O: posterior surface, mid-portion of tibia
I: base of distal phlanx of four small toes
A: flexes four small toes, plantar flexes foot
N: tibial n.
Flexor Hallucis longus
O: distal posterior surface of fibula and adjacent interosseous membrane
I: base of distal phlanx of great toe
A: flexes great toe, plantar flexes foot
N: Tibial N.
Tibialis posterior
O: upper portion of tibia, fibula and intervening interosseous membrane
I: plantar surface of metatarsals 2,3,4, navicular, medial cuneiform and ALL other tarsals except talus
A: inverts and plantar flexes foot
N: tibial n.
NOTE; the passage of tendons from behind the medial malleolus from anteromedial to posterolateral is Tom, Dick and Harry. the order of muscle bellies is Dick, Tom and Harry. this is due to the passage of the tendon of tibialis posterior deep and medial to the tendon of flexor digitorum longus as it descends to cross the ankle joint
