Muscles of the Posterior Leg

Flashcards covering the names, meanings, origins, insertions, nerves, blood supply, and functions of the muscles in the posterior compartment of the leg.

Gastrocnemius

A posterior, superficial muscle meaning 'belly/bulk at leg'. Origin: medial head on posterior surface of femur above medial condyle, lateral head on posterior surface of lateral condyle of femur. Insertion: calcaneal tendon on posterior surface of calcaneus. Function: strong plantar flexion of foot and weak flexion of knee.

Soleus

A posterior, superficial muscle meaning 'sandal' or 'fish'. Origin: soleal line and medial border of tibia, and the upper $1/4$-posterior head, neck, and proximal shaft of fibula. Insertion: calcaneal tendon. Function: plantar flexes foot and knee; acts as a venous pump.

Plantaris

A posterior, superficial muscle meaning 'sole of foot'. Origin: distal end of lateral supracondylar ridge of femur, above head of gastrocnemius. Insertion: calcaneal tendon, posterior surface of calcaneus (medial, deep to gastrocnemius). Function: plantar flexes foot.

Flexor digitorum longus

A posterior, deep muscle meaning 'long flexor of toes'. Origin: medial side of posterior surface of tibia, below soleal line. Insertion: plantar surfaces of bases of distal phalanges of lateral $4$ toes. Function: flexes lateral $4$ toes.

Flexor hallucis longus

A posterior, deep muscle meaning 'long flexor of great toe'. Origin: posterior surface (distal $3/4$) of fibula and IOM. Insertion: plantar surface of distal phalanx of great toe. Function: maintain medial longitudinal arch of foot.

Tibialis posterior

A posterior, deep muscle meaning 'back of tibia'. Origin: posterior surface of IOM and adjacent regions of tibia and fibula. Insertion: tuberosity of navicular and adjacent region of medial cuneiform, cuboid, and bases of $4$ medial metatarsals. Function: inversion and plantarflexion of foot, support of medial arch.

Popliteus

A posterior, deep muscle meaning 'knee muscle'. Origin: lateral head on round tendon of lateral femoral condyle, medial head on flat aponeurosis to lateral meniscus and capsule of knee joint. Insertion: popliteal surface of the posterior tibia above the soleal line. Function: unlocks knee joint (lateral rotation of femur on tibia), stabilizes and controls position of lateral meniscus.

Superficial Posterior Leg Muscles

A group of muscles located posteriorly in the leg including the gastrocnemius, plantaris, and soleus.

Deep Posterior Leg Muscles

A group of muscles located posteriorly in the leg including the popliteus, flexor digitorum longus, tibialis posterior, and flexor hallucis longus.

Posterior Leg Muscle Nerve Supply

The tibial nerve supplies all the listed muscles of the posterior leg: gastrocnemius, soleus, plantaris, flexor digitorum longus, flexor hallucis longus, tibialis posterior, and popliteus.

Posterior Leg Muscle Blood Supply

The posterior tibial artery provides blood supply to all the listed muscles of the posterior leg: gastrocnemius, soleus, plantaris, flexor digitorum longus, flexor hallucis longus, tibialis posterior, and popliteus.