Ankle Deep Posterior Compartment

Question 1

What are the muscles in the deep posterior compartment

Answer 1

Popliteus
Tibialis posterior
Flexor digitorum Longus
Flexor hallucis Longus

Question 2

What is the origin, insertion and action for popliteus

Answer 2

Origin - outer surface of lateral femoral condyle, below epicondyle
Insertion - posterior of proximal tibia, above soleal line
Action - laterally rotates femur on tibia

Question 3

What is the origin, insertion and action for tibialis posterior

Answer 3

Origin - medial part - posterior of tibia and Interosseous membrane
- lateral part - proximal posterior surface of fibula
Insertion - tubercle on medial side of navicular and plantar surface of medial cuneiform. Slips to plantar surfaces of all tarsal bones except talus
Action - inverts foot and assists plantar flexion at ankle. Assists support of medial longitudinal arch

Question 4

What is the origin, insertion and action for flexor digitorum Longus

Answer 4

Origin - medial aspect of posterior tibia
Insertion - 4 tendons to plantar aspect of the bases of distal phalanges
Action - flexion of toes 2-5 at DIP jt, PIP jt, & MTP jt
- assists plantarflexion of foot

Question 5

What is the origin, insertion and action for flexor hallucis Longus

Answer 5

Origin - lower 2/3 of posterior surface of fibula and Interosseous membrane
Insertion - plantar surface of base of distal phalanx of great toe
Action - flexion of all joints and great toe
- assists plantarflexion of foot at ankle joint