Posterior leg Flashcards
What separates the superficial posterior muscle group and the deep posterior muscle group?
Transverse septum; Tibial nerve and posterior tibial vessels are deep to the transverse crural intermuscular septum
What is the most superficial posterior leg muscle?
Gastrocnemius
Origins of the 2 heads of gastrocnemius
Medial head : popliteal surface above medial femoral condyle
Lateral head : Lateral femoral condyle
Insertion, innervation and action of gastrocnemius
Insertion: Posterior calcaneal tendon
Innervation: Tibial nerve
Action: Plantarflexion with extended leg, raise heel, flex leg
Where may a fabella be located?
Close to lateral head of gastrocnemius proximal attachment
What is a fabella and why could it be bad?
It is a sesamoid bone that may be very painful if stress fractured during total knee replacement
Where does soleus lie?
Deep to gastrocnemius
Origin, insertion, innervation and action of Soleus
O: Posterior head and upper body of fibula and soleal line on tibia
I: Calcaneal tendon
Innervation: Tibial nerve
Action: plantarflexion
What forms the triceps surae?
The 2 heads of gastrocnemius and soleus – calf prominence
Origin, insertion, innervation and action of Plantaris
O: Inferior aspect of lateral supracondylar line
I: Calcaneal tendon
Innervation: tibial nerve
Action: Proprioception of where foot is, weak assist in plantarflexion
What is unique about Plantaris?
It is small but has a very long tendon that runs between gastrocnemius and soleus
What 2 things can happen to the plantaris tendon?
Used for reconstructive hand tendon surgery
Can also be ruptured during violent ankle movements of athletes – they will not be able to bare any weight
What muscle lies deep to plantaris?
Popliteus
Origin, insertion, innervation and action of poplietus
O: Lateral femoral condyle and lateral meniscus
I: Superomedial to soleal line on posterior tibia
Innervation: tibial nerve
Action: Weak flexion of knee, unlocks extended leg with lateral rotation of femur
What is the largest deep posterior leg muscle?
Flexor hallucis longus
Origin, insertion, innervation and action of flexor hallucis longus
O: Inferior fibula
I: Base of 1 distal phalanx (big toe)
Innervation: tibial nerve
Action: flex great toe (hallux) and plantarflexion
Origin, insertion, innervation and action of flexor digitorum longus
O: inferior to soleal line on posterior tibia
I: Base of 2-5th distal phalanges
Innervation: tibial nerve
Action: flex digits 2-5 and plantarflexion
Origin, insertion, innervation, and action of posterior tibialis
O: SAME PLANE AS BONES - interosseous membrane, inferior to soleal line on tibia, posteromedial side of fibula
I: Navicular tuberosity, cuneiforms, 2-4 metatarsals
Innervated by tibial nerve
Action: Plantarflexion and innerversion
What nerve innervates every muscle in the posterior leg?
Tibial Nerve
Where can you palpate the posterior tibial artery?
Posterior to medial malleolus btwn medial calcaneal tendon and have pt invert their foot
Why would you need to palpate the posterior tibial artery?
It is used to examine patients that have occlusive peripheral artery disease
They will present with leg cramps and pain during walking that goes away after rest
Describe the sciatic nerve splitting down the leg?
Sciatic splits into tibial and common fibular
Common fibular gives rise to lateral sural cutaenous
Tibial gives rise to medial sural cutaneous that runs with the small saphenous vein
The medial sural cutaneous joins with a communicating sural to form the sural nerve proper
Describe the popliteal artery splitting down the leg?
Popliteal artery splits into the posterior tibial and anterior tibial
The anterior tibial goes superior anterior at interosseous membrane
The posterior tibial gives off a fibular branch
The posterior runs down the leg and eventually splits in to the medial and lateral plantar arteries
What tendons contribute to dynamic arch support of the foot?
Tibialis posterior, tibialis anterior, flexor hallucis longus, fibularis longus, intrinsic plantar muscles
What ligaments contribute to the passive arch support of the foot?
Plantar aponeurosis, long plantar, short plantar, plantar calcaneonavicular
What is the order of the deep posterior leg muscles as the pass the medial side of the foot?
Tom - tibialis posterior
Dick - flexor digitorum longus
a.n. - posterior tibial artery and tibial nerve
Harry - flexor hallucis longus
