Deep Posterior leg muscles

Question 1

What is the origin, insertion, innervation and function of Tibialis Posterior (deep posterior)

Answer 1

i. Origin: tibia/fibula
ii. Insert: navicular bone, cuneiform bones, cuboid bones, and base of metatarsals
iii. Nerve: tibial nerve
iv. Action: plantar flexion at ankle , inversion of foot ankle/foot
(anterior)- tendon crosses joint medially

Question 2

What is the origin, insertion, innervation and function of Flexor digitorum longus (deep posterior)

Answer 2

i. Origin: tibia
ii. Insert: digits 2-5
iii. Nerve: tibial nerve
iv. Action: plantar flex digits 2-5; plantar flex

Question 3

What is the origin, insertion, innervation and function of Flexor Hallicus longus (posterior)
(deep posterior compartment)

Answer 3

i. Origin: fibula
ii. Insert: big toe
iii. Nerve: tibial nerve
iv. Action: plantar flexion at ankle, plantar flexion of big toe

Question 4

What is the origin, insertion, innervation, and function of Popliteus
* not in the posterior compartment

Answer 4

• extends over posterior aspect of knee joint

i. Origin: lateral condyle of femur and posterior horn of lateral meniscus
ii. Insert: Posterior proximal tibia
iii. Nerve: tibial nerve
iv. Action: key to unlock knee; stabilizes the knee; medial rotation of tibia to unlock knee