Muscles of the posterior compartment of the leg

Question 1

What are the muscles of the SUPERFICIAL posterior compartment of the leg?

Answer 1

• Gastrocnemius
• Plantaris
• Soleus

Question 2

Gastrocnemius

Answer 2

O: Lateral femoral condyle (lateral head) and medial femoral condyle (medial head)

I: Calcaneal tuberosity (via Achilles/Calcaneal tendon)

I: Tibial nerve

A: Plantarflexion and assists knee flexion

Question 3

Plantaris

Answer 3

O: Lateral supracondylar line of femur

I: Calcaneal tuberosity (via Achilles/Calcaneal tendon)
-descends medially

I: Tibial nerve

A: Weak plantarflexion and knee flexor

Question 4

Soleus

Answer 4

O: Soleal line of the tibia and proximal fibula

I: Calcaneal tuberosity (via Achilles/Calcaneal tendon)

I: Tibial nerve

A: Plantarflexion

Question 5

What are the muscles of the DEEP posterior compartment of the leg?

Answer 5

• Popliteus
• Flexor digitorum longus
• Flexor hallucis longus
• Tibialis posterior

Question 6

Popliteus

Answer 6

O: Tibia (proximal to soleal line)

I: Lateral condyle of femur

I: Tibial nerve

A: Laterally rotates thigh (to unlock knee joint)

Question 7

Tibialis Posterior

Answer 7

O: Interosseous membrane, and posterior surfaces of tibia and fibula

I: Plantar surface of navicular and medial cunneiform (after passing posterior medial malleolus)

I: Tibial nerve

A: Plantarflexion and inversion

Question 8

Flexor Digitorum Longus

Answer 8

O: Medial surface of the tibia

I: 4 tendons to base of distal phalanx of 2nd to 5th toes (after passing posterior medial malleolus)

I: Tibial nerve

A: Flexion of toes, plantarflexion and inversion

Question 9

Flexor Hallucis Longus

Answer 9

O: Posterior surface of fibula

I: Plantar surface of the base of distal phalanx of great toe (after passing posterior medial malleolus)

I: Tibial nerve

A: Flexion of great toe, plantarflexion and inversion