Leg Flashcards
What are the four muscles of the anterior compartment?
Tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius
What are the three compartments of the leg?
Anterior, lateral, and posterior compartments
What are the two muscles of the lateral compartment?
Fibularis longus and fibularis brevis
What does the deep fibular nerve pierce as it goes deep?
Intermuscular septum
What does the anterior tibial artery pierce as it goes deep?
Interosseous membrane
What divides the superificial and deep compartments of the posterior leg?
Transverse intermuscular septum
What are the superficial muscles of the posterior compartment of the leg?
Gastrocnemius, soleus, and plantaris
Triceps surae
Tendons of the gastrocnemius and soleus come together to form the calcaneal tendon
What is the most superficial muscle in the posterior compartment of the leg?
Gastrocnemius
What are the four muscles of the deep compartment of the posterior leg?
Popliteus, flexor digitorum longus, flexor hallucis longus, and tibialis posterior
What is the only muscle of the deep compartment of the posterior thigh to act on the knee joint?
Popliteus
How do the popliteal artery and tibial nerve exit the popliteal fossa?
Tendinous arch of soleus
Tibialis anterior
Origin: lateral condyle and superior half of the lateral surface of the tibia and interosseous membrance
Insertion: medial and inferior surfaces of medial cuneiform and base of 1st metatarsal
Innervation: deep fibular nerve (L4,L5)
Action: dorsiflexes ankle, inverts ankle, and supports medial longitudinal arch of foot
Extensor hallucis longus
Origin: middle part of the anterior surface of the fibula and the interosseous membrane
Insertion: dorsal aspect of base of the distal phalanx of the great toe
Innervation: deep fibular nerve (L5,S1)
Action: extend great toe and dorsiflex ankle
Extensor digitorum longus
Origin: lateral condyle of tibia and superior three fourths of the anterior surface of the interosseous membrane
Insertion: middle and distal phalanges of the lateral four digits
Innervation: deep fibular nerve (L5,S1)
Action: extend lateral four digits and dorsiflex ankle
Fibularis tertius
Origin: inferior third of the anterior surface of the fibula and interosseous membrane
Insertion: dorsum of base of 5th metatarsal
Innervation: deep fibular nerve (L5,S1)
Action: dorsiflex the ankle and aid in eversion of foot
Fibularis longus
Origin: superior two thirds of the lateral surface of the fibula
Insertion: medial cuneiform and base of the the 1st metatarsal
Innervation: superficial fibular nerve (L5,S1,S2)
Action: everts foot, weakly plantarflexes ankle, and supports transverse arch of foot
Fibularis brevis
Origin: inferior two thirds of the lateral surface of the fibula
Insertion: dorsal surface of tuberosity of base of 5th metatarsal
Innervation: superficial fibular nerve (L5,S1,S2)
Action: none
Gastrocnemius
Origin: (lateral head) lateral aspect of lateral condyle of femur (medial head) popliteal surface of femur superior to medial condyle
Insertion: posterior surface of calcaneous via calcaneal tendon
Innervation: tibial nerve (S1,S2)
Action: plantarflexes ankle when knee is extended, raises heel during walking, and flexes leg at knee joint
Soleus
Origin: posterior aspect of head of fibula, superior quarter of posterior surface of fibula, soleal line, and medial border of tibia
Insertion: posterior surface of calcaneous via calcaneal tendon
Innervation: tibial nerve (S1,S2)
Action: plantarflexes ankle
Plantaris
Origin: inferior end of lateral supracondylar line of femur and oblique popliteal ligament
Insertion: posterior surface of calcaneous via calcaneal tendon
Innervation: tibial nerve (S1,S2)
Action: assists gastrocnemius with plantarflexion of ankle
Popliteus
Origin: lateral surface of lateral condyle of femur and lateral meniscus
Insertion: posterior surface of tibia superior to soleal line
Innervation: tibial nerve (L4,L5,S1)
Action: weakly flexes knee and unlocks knee joint by laterally rotating femur on fixed tibia
Flexor hallucis longus
Origin: inferior 2/3 of posterior surface of fibula and inferior part of interosseous membrane
Insertion: base of distal phalanx of great toe
Innervation: tibial nerve (S2,S3)
Action: flexes great toe, weakly plantarflexes ankle, and supports medial longitudinal arch of foot
Flexor digitorum longus
Origin: medial part of posterior surface of tibia inferior to soleal line and by a broad tendon to the fibula
Insertion: bases of distal phalanges of lateral four digits
Innervation: tibial nerve (S2,S3)
Action: flexes lateral four digits, plantarflexes ankle, and supports longitudinal arch of foot
Tibialis posterior
Origin: interosseous membrane, posterior surface of tibia inferior to soleal line, and posterior surface of fibula
Insertion: tuberosity of navicular, cuneiforms, cuboid, and bases of 2-4th metatarsals
Innervation: tibial nerve (L4,L5)
Action: plantarflexes ankle, inverts foot, and supports medial longitudinal arch of foot
What are the muscles of the tarsal tunnel?
Tibialis posterior, flexor digitorum longus, and flexor hallucis longus
