Posterior deeper leg compartment: plantarflexion of foot deeper group

Question 1

popliteus

Answer 1

• origin: lateral condyle of the femur and lateral meniscus
• insertion: posterior surface of the tibia above soleal line
• action: flexes and medially rotates leg (with the foot planted, it rotates the thigh laterally)
• limb supporting weight: laterally rotated femur on tibia to unlock knee joint

Question 2

flexor digitorum longus

Answer 2

• origin: middle half of the posterior surface of the tibia below soleal line
• insertion: bases of distal phalanxes 2-5
• action: flexes digits 2-5, aids with plantaflexion and inversion
• helps support longitudinal arches

Question 3

flexor hallucis longus

Answer 3

• origin: lower 2/3 of the posterior surface of the fibula and interosseous membrane
• insertion: base of the distal phalanx of the great toe
• action: flexes distal phalanx and plantarflexes foot at ankle

Question 4

tibialis posterior

Answer 4

• origin: interosseous membrane, posterior aspect of tibia inferior to soleal line, posterior surface of fibula
• insertion: tuberosity of the navicular bone, cuneiform, cuboid, sustentaculum tali, bases of 2,3,4 metatarsals
• action: plantarflexion and inversion of foot