Posterior compartment of the leg

Question 1

What are the muscles in the posterior compartment of the leg? (superficial)

Answer 1

• Gastrocnemeus
• Soleus
• Plantaris

Question 2

What is the main action of the posterior compartment muscles

Answer 2

-Plantarflex the ankle

Question 3

What are the attachments for the gastrocnemius

Answer 3

• Lateral condyle OR popliteal condyle

- Posterior calcaneus via the calcaneal tendon

Question 4

What joint does the gastrocnemius cross and what is its action

Answer 4

Crosses the knee

• Flexes leg at knee joint
• Plantarflexes ankle when knee is extended

Question 5

This muscle plantarflexes the ankle at ANY position

Answer 5

Soleus

-it does this because it doesn’t cross the knee joint

Question 6

What are the attachments of the soleus

Answer 6

• Soleal line of the tibia and head of fibula

- Posterior calcaneus via the calcaneal tendon

Question 7

What is the role of the plantaris muscle

Answer 7

-Proprioception

Question 8

What are the attachments for the plantaris muscle

Answer 8

• Lateral supracondylar line of the femur (Above the lateral condyle of the femur)
• Posterior calcaneus via the calcaneal tendon

Question 9

Describe the muscle fiber type of the gastrocnemius

Answer 9

• White
• Fast twitch (type 2)
• Powerful spurt contractions

Question 10

Describe the muscle fiber type of the soleus

Answer 10

• Red
• Slow Twitch (Type 1)
• Fatigue resistant

Question 11

What nerve root is the calcaneus tendon

Answer 11

S1 nerve root

Question 12

This divides the deep and superficial posterior compartments

Answer 12

Transverse intermuscular septum

Question 13

What is the transverse intermuscular membrane continuous with?

Answer 13

Flexor retinaculum

Question 14

Is the flexor retinaculum medial or lateral

Answer 14

Medial

Question 15

What is the common nerve supply for the superficial posterior compartment

Answer 15

Tibial nerve

Question 16

What is the common arterial supply for the superficial posterior compartment

Answer 16

• Fibular artery

- Posterior tibial artery

Question 17

What are the muscles in the deep posterior compartment

Answer 17

• Tibialis posterior
• Flexor hallicus longus
• Flexor digitorum longus
• Popliteus

Question 18

What is unique about the flexor hallicus longus

Answer 18

-FHC starts LATERALLY and crosses MEDIALLY to insert of the base of the distal phalynx of the big toe

Question 19

What are the attachments of the flexor hallicus longus

Answer 19

• Inferior and posterior surface of the fibula

- Distal phalynx of the great toe

Question 20

The tendons of the FHL and FDL cross on the foot, where does the flexor digitorum longus attach

Answer 20

• Medial part of the posterior surface of the tibia

- Bases of distal phalynx of lateral 4 digits

Question 21

What 2 muscle tendons cross and create the “Stur up” which is important for the arch of the foot

Answer 21

• Tibialis posterior tendon

- Fibularis longus tendon

Question 22

This muscle lies on the floor of the popliteal fossa

Answer 22

Popliteus muscle

Question 23

What are the attachments of the popliteal muscle

Answer 23

• Lateral condyle of the femur

- Posterior surface of the tibia

Question 24

What is the main action of the popliteus muscle

Answer 24

Pull the lateral meniscus and femur posteriorly when the knee is partically flexes
-Aids the PLC in preventing the femur from slipping off of the tibial plateau

Question 25

What are the attachments of the flexor digitorum longus

Answer 25

- Medial part of the posterior surface of the tibia | - Bases of distal phalanx of lateral 4 digits

Question 26

This muscle of the foot realigns the pull of the FDL tendons

Answer 26

Quadratus plantae m

Question 27

Where does the tibialis posterior lie

Answer 27

- On top of the interosseous membrane between the tibia and the fibula - Navicular, cuneiforms, and bases of metatarsals 2-4

Question 28

What are the actions of the tibials posterior

Answer 28

- Plantarflexes - Inverts - Fixes the medial longitudinal arch during weight bearing

Question 29

What are the tendons that pass posterior to the medial malleolus in order from anterior to posterior

Answer 29

Tom, Dick, Harry - Tibialis Posterior - Flexor Digitorum longus - Flexor hallicus longus

Question 30

This membrane runs between the tibia and the fibula and it seperates the anterior from the posterior compartment

Answer 30

Interosseous membrane

Question 31

This sperates the anterior from the lateral compartment

Answer 31

Anterior intermuscular septum

Question 32

This seperates the lateral and the deep posterior compartment

Answer 32

Posterior intermuscular septum

Question 33

This divides the superficial from the deep compartment

Answer 33

Transverse intermuscular septum