Posterior Leg Flashcards
The talus contains a structure known as the posterior process which has a medial and lateral tubercle. What is the significance of these two tubercles?
Creates a groove for the FHL tendon
What does the calcaneus articulate with?
Talus superiorly
Cuboid anteriorly
What is the sustentaculum tali?
A ligament or shelf like projection that supports the talus and provides a groove for the FHL
What does the navicular bone articulate with?
Head of talus posteriorly
Cuneiforms anteriorly
Cuboid laterally
What is the significance of the navicular tuberosity?
Site of tibialis posterior attachment
What divides the posterior compartment of the leg into deep and superficial groups?
Transverse septa
Which muscles are in the superficial posterior compartment of the leg?
Gastrocnemius, soleus and plantaris
Which muscles are in the deep posterior compartment of the leg?
Popliteus, FHL, FDL, and tibialis posterior
Where are the tibial nerve and posterior tibial vessels located within the posterior compartment?
Deep to transverse crural intermuscular septum
Which nerve innervates all the muscles within the posterior compartment of the leg?
Tibial nerve
Structures in each compartment of the leg share what components?
Same general function, nerve, artery and vein
What is the most superficial muscle in the posterior compartment and that also crosses both the knee and ankle joints?
Gastrocnemius
What are the sites of origin for the medial and lateral heads of the gastrocnemius?
Medial head: medial femoral condyle
Lateral head: lateral femoral condyle
What is the insertion site for the gastrocnemius muscle?
Posterior surface of calcaneus via tendon calcaneus (Achilles tendon)
What is the overall action of the posterior compartment muscles?
Plantarflexion
What is the unique action of the gastrocnemius?
Flexes leg at the knee joint
The lateral head of the gastrocnemius may have a sesamoid bone close to its proximal attachment known as a fabella. What is its function and clinical significance?
Possibly provide leverage for lateral head of gastrocnemius
Painful fabellar stress fracture may accompany total knee replacement
What are the proximal attachments for the soleus muscle?
Soleal line of tibia, posterior head of fibula and superior 1/4 of posterior fibula
What does the soleus insert on?
Into posterior surface of calcaneus via tendo calcaneus (Achilles tendon)
What do the gastrocnemius and soleus form?
A tripartite muscle known as the triceps surae which forms the calf prominence
What are the attachment sites for the plantaris muscle?
O: lateral supracondylar line
I: posterior surface of calcaneus via calcaneal tendon
What is the course of the plantaris tendon?
Runs between gastrocnemius and soleus
Which muscle of the superficial posterior compartment is proposed to be a proprioceptive organ for foot position?
Plantaris muscle (has a high density of proprioceptive receptors)
What are the unique actions of the plantaris muscle?
Only weak plantarflexion
Leg flexion
Which posterior compartment muscle forms the floor of the popliteal fossa?
Popliteus
What are the attachments for the popliteus muscle?
O: posterior tibia superior to soleal line
I: lateral femoral condyle and lateral meniscus
What are the unique functions of the popliteus muscle?
Unlocks extended leg by laterally rotating femur on a stationary tibia
Weakly flexes leg
Which structures does the popliteus separate?
The laterall collateral L from the lateral meniscus
What are the attachment sites for FHL?
O: inferior 2/3 of posterior fibula
I: base of distal phalanx of great toe
What are the unique actions for the FHL muscle?
Flexes great toe
What are the attachment sites for FDL?
O: posterior tibia inferior to soleal line
I: distal phalanx base of lateral 4 digits
Describe the course of FDL’s tendon
Passes posterior to tibialis posterior -> passes diagonally in sole of the foot superficial to FHL tendon -> divides into four tendons in the middle of the sole of the foot that pass to lateral 4 digits
What is the unique action of FDL?
Flexes lateral 4 digits
What is the proximal attachment for the tibialis posterior muscle?
Interosseous membrane, posterior tibia to soleal line, posteromedial surface of fibula
What is the distal attachment for tibialis posterior?
Navicular tuberosity, cuneiforms and 2-4 metatarsal bones
What is the deepest posterior compartment muscle?
Tibialis posterior
What is the unique action for the tibialis posterior muscle?
Inversion
Where are the superior medial and lateral genicular arteries located?
Just superior to medial and lateral head of the gastrocnemius
Where is the inferior medial genicular A located?
Deep to medial head of gastrocnemius
Where is the inferior lateral genicular artery located?
Deep to plantaris and superficial to popliteus
Do genicular arteries branch into muscles?
NO
Describe the course of the tibial nerve
Passes with posterior tibial vessels deep to soleus and posterior to tibialis posterior
Leaves posterior compartment by passing deep to flexor retinaculum b/w medial malleolus and calcaneus
How does the tibial nerve end?
By dividing into medial and lateral plantar nerves (posteroinferior to medial malleolus)
Describe the course of the posterior tibial A
Begins near inferior border of popliteus
Passes inferomedially on posterior surface of tibialis posterior w/ tibial nerve
Runs deep to flexor retinaculum
Ends by dividing into medial and lateral plantar arteries
What is the largest branch of the posterior tibial A?
Fibular A
Describe the course of the fibular A
Begins inferior to distal border of popliteus
Descends towards fibula under the FHL
Ends by piercing interosseous membrane and anastomosing with anterior lateral malleolar A
Which artery vascularizes the posterior compartment?
Posterior tibial A and fibular A
What is the tendon of the plantaris muscle commonly used for?
In reconstructive surgery of hand tendons
It’s removal doesnt affect knee or ankle movements
What can rupture during violent ankle movements?
Plantaris tendon
Common injury in basketball players, sprinters and ballet dancers
Pain may be so severe that person in unable to bear weight
Where can the posterior tibial pulse be palpated?
Between posterior surface of medial malleolus, medial border of calcaneal tendon and deep to flexor retinaculum (important to have pt relax this by inverting foot)
What is the posterior tibial pulse used for?
Examining patients with occlusive peripheral artery disease (intermittent claudication)
What causes peripheral occlusive artery disease?
Condition caused by ischemia of leg muscles due to narrowing or occlusion of leg arteries
Characterized by leg crams and pain during walking (disappears after rest)
