Leg Flashcards
What motion are muscles of the anterior compartment of the leg responsible for?
Dorsiflexion of the ankle joint and extension of the toes
What four muscles make up the anterior compartment of the leg?
Tibialis anterior, extensor digitorum longus, extensor hallucis longus, fibularis tertius
What nerve innervates the anterior compartment of the leg?
Deep fibular (peroneal) nerve, one of two terminal branches of common fibular nerve
Which artery does the deep fibular nerve run with?
Anterior tibial artery
Which artery supplies structures in the anterior compartment of the leg?
Anterior tibial artery, a smaller terminal branch of the popliteal artery
What two muscles are in the lateral compartment of the leg?
Fibularis longus and fibularis brevis
What nerve innervates the lateral compartment of the leg?
Superficial fibular nerve, a terminal branch of the common fibular nerve
What happens to the anterior tibial artery at the ankle joint, midway between the malleoli?
It becomes the dorsalis pedis artery
What is the origin of the tibialis anterior?
Lateral condyle and superior 2/3 of lateral surface of tibia and interosseous membrane
Where does the tibialis anterior insert?
Medial and inferior surfaces of medial cuneiform and base of 1st metatarsal
What is the innervation of the tibialis anterior?
Deep fibular nerve (L4, L5)
What action does the tibialis anterior perform?
Dorsiflexes ankle; inverts foot; supports medial longitudinal arch of foot
What is the origin of the extensor hallucis longus?
Middle part of anterior surface of fibula and interosseous membrane
Where does the extensor hallucis longus insert?
Dorsal aspect of base of distal phalanx of great toe (hallux)
What is the innervation of the extensor hallucis longus?
Deep fibular nerve (L5, S1)
What action does the extensor hallucis longus perform?
Extends great toe; dorsiflexes ankle
What is the origin of the extensor digitorum longus?
Lateral condyle of tibia and superior 2/3 of anterior surface of fibula and interosseous membrane
Where does the extensor digitorum longus insert?
Middle and distal phalanges of lateral four digits
What is the innervation of the extensor digitorum longus?
Deep fibular nerve (L5, S1)
What action does the extensor digitorum longus perform?
Extends lateral four digits; dorsiflexes ankle
What is the origin of the fibularis tertius?
Inferior third of anterior surface of fibula and interosseous membrane
Where does the fibularis tertius insert?
Dorsum of base of 5th metatarsal
What is the innervation of the fibularis tertius?
Deep fibular nerve (L5, S1)
What action does the fibularis tertius perform?
Dorsiflexes ankle; aids in eversion of foot
What is the origin of the fibularis longus?
Head and superior two thirds of lateral surface of fibula
Where does the fibularis longus insert?
Base of 1st metatarsal and medial cuneiform
What is the innervation of the fibularis longus?
Superficial fibular nerve (L5, S1, S2)
What action does the fibularis longus perform?
Evert foot; weakly plantar flex ankle, and supports transverse arch of foot
What is the origin of the fibularis brevis?
Middle part of lateral surface of fibula
Where does the fibularis brevis insert?
Dorsal surface of tuberosity of base of 5th metatarsal
What is the innervation of the fibularis brevis?
Superficial fibular nerve (L5, S1, S2)
What action does the fibularis brevis perform?
Evert foot; weakly plantar flex ankle
What movement are muscles in the posterior compartment of the leg responsible for?
Plantarflexion
What muscles make up the superficial muscles of the posterior leg?
Gastrocnemius, soleus, and plantartis
What type of muscle is the gastrocnemius?
Fusiform muscle
What muscles make up the deep muscles of the posterior leg?
Popliteus, flexor digitorum longus, flexor hallucis longus, tibialis posterior
Which muscle unlocks the fully extended knee joint?
Popliteus
Which nerve supplies all the muscles in the posterior compartment of the leg?
Tibial nerve
Which artery supplies the posterior compartment of the leg and foot?
Posterior tibial artery
What is the origin of the gastrocnemius?
Lateral head- lateral aspect of lateral condyle of femur
Medial head- popliteal surface of femur, superior to medial condyle
Where does the gastrocnemius insert?
Posterior surface of calcaneus via calcaneal tendon
What is the innervation of the gastrocnemius?
Tibial nerve (S1, S2)
What action does the gastrocnemius perform?
Plantarflexes ankle when knee is extended; raises heel during walking and flexes knee joint
What is the origin of the soleus?
Posterior aspect of head of fibula, superior quarter of posterior surface of fibula, soleal line, and medial border of tibia
Where does the soleus insert?
Posterior surface of calcaneus via calcaneal tendon
What is the innervation of the soleus?
Tibial nerve (S1, S2)
What action does the soleus perform?
Plantarflexes ankle; steadies leg on foot
What is the origin of the plantaris?
Inferior end of lateral supracondylar line of femur and oblique popliteal ligament
Where does the plantaris insert?
Posterior surface of calcaneus via calcaneal tendon
What is the innervation of the plantaris?
Tibial nerve (S1, S2)
What action does the plantaris perform?
Weakly assists gastrocnemius in plantarflexing ankle; function is probably mainly propioceptive
What is the origin of the popliteus?
Lateral surface of lateral condyle of femur and lateral meniscus
Where does the popliteus insert?
Posterior surface of tibia, superior to soleal line
What is the innervation of the popliteus?
Tibial nerve (L4, L5, S1)
What action does the popliteus perform?
Weakly flexes knee and unlocks it by laterally rotating femur on fixed tibia
What is the origin of the flexor hallucis longus?
Inferior two thirds of posterior surface of fibula and inferior part of interosseous membrane
Where does the flexor hallucis longus insert?
Base of distal phalanx of great toe (hallux)
What is the innervation of the flexor hallucis longus?
Tibial nerve (S2, S3)
What action does the flexor hallucis longus perform?
Flexes great toe at all joints; weakly plantarflexes ankle; support medial longitudinal arch of foot
What is the origin of the flexor digitorum longus?
Medial part of posterior surface of tibia inferior to soleal line and by a broad tendon of fibula
Where does the flexor digitorum longus insert?
Bases of distal phalanges of lateral four digits
What is the innervation of the flexor digitorum longus?
Tibial nerve (S2, S3)
What action does the flexor digitorum longus perform?
Flexes lateral four digits; plantarflexes ankle; supports longitudinal arch of foot
What is the origin of the tibialis posterior?
Interosseous membrane, posterior surface of tibia inferior to soleal line, and posterior surface of fibula
Where does the tibialis posterior insert?
Primarily to tuberosity of navicular; also to cuneiforms, cuboid, and bases of 2nd-4th metatarsals
What is the innervation of the tibialis posterior?
Tibial nerve (L4, L5)
What action does the tibialis posterior perform?
Plantarflexes ankle; inverts foot; supports medial longitudinal arch of foot
