Posterior compartment of the leg Flashcards
What are the muscles in the posterior compartment of the leg? (superficial)
- Gastrocnemeus
- Soleus
- Plantaris
What is the main action of the posterior compartment muscles
-Plantarflex the ankle
What are the attachments for the gastrocnemius
- Lateral condyle OR popliteal condyle
- Posterior calcaneus via the calcaneal tendon
What joint does the gastrocnemius cross and what is its action
Crosses the knee
- Flexes leg at knee joint
- Plantarflexes ankle when knee is extended
This muscle plantarflexes the ankle at ANY position
Soleus
-it does this because it doesn’t cross the knee joint
What are the attachments of the soleus
- Soleal line of the tibia and head of fibula
- Posterior calcaneus via the calcaneal tendon
What is the role of the plantaris muscle
-Proprioception
What are the attachments for the plantaris muscle
- Lateral supracondylar line of the femur (Above the lateral condyle of the femur)
- Posterior calcaneus via the calcaneal tendon
Describe the muscle fiber type of the gastrocnemius
- White
- Fast twitch (type 2)
- Powerful spurt contractions
Describe the muscle fiber type of the soleus
- Red
- Slow Twitch (Type 1)
- Fatigue resistant
What nerve root is the calcaneus tendon
S1 nerve root
This divides the deep and superficial posterior compartments
Transverse intermuscular septum
What is the transverse intermuscular membrane continuous with?
Flexor retinaculum
Is the flexor retinaculum medial or lateral
Medial
What is the common nerve supply for the superficial posterior compartment
Tibial nerve
What is the common arterial supply for the superficial posterior compartment
- Fibular artery
- Posterior tibial artery
What are the muscles in the deep posterior compartment
- Tibialis posterior
- Flexor hallicus longus
- Flexor digitorum longus
- Popliteus
What is unique about the flexor hallicus longus
-FHC starts LATERALLY and crosses MEDIALLY to insert of the base of the distal phalynx of the big toe
What are the attachments of the flexor hallicus longus
- Inferior and posterior surface of the fibula
- Distal phalynx of the great toe
The tendons of the FHL and FDL cross on the foot, where does the flexor digitorum longus attach
- Medial part of the posterior surface of the tibia
- Bases of distal phalynx of lateral 4 digits
What 2 muscle tendons cross and create the “Stur up” which is important for the arch of the foot
- Tibialis posterior tendon
- Fibularis longus tendon
This muscle lies on the floor of the popliteal fossa
Popliteus muscle
What are the attachments of the popliteal muscle
- Lateral condyle of the femur
- Posterior surface of the tibia
What is the main action of the popliteus muscle
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
What are the attachments of the flexor digitorum longus
- Medial part of the posterior surface of the tibia
- Bases of distal phalanx of lateral 4 digits
This muscle of the foot realigns the pull of the FDL tendons
Quadratus plantae m
Where does the tibialis posterior lie
- On top of the interosseous membrane between the tibia and the fibula
- Navicular, cuneiforms, and bases of metatarsals 2-4
What are the actions of the tibials posterior
- Plantarflexes
- Inverts
- Fixes the medial longitudinal arch during weight bearing
What are the tendons that pass posterior to the medial malleolus in order from anterior to posterior
Tom, Dick, Harry
- Tibialis Posterior
- Flexor Digitorum longus
- Flexor hallicus longus
This membrane runs between the tibia and the fibula and it seperates the anterior from the posterior compartment
Interosseous membrane
This sperates the anterior from the lateral compartment
Anterior intermuscular septum
This seperates the lateral and the deep posterior compartment
Posterior intermuscular septum
This divides the superficial from the deep compartment
Transverse intermuscular septum
