Posterior Muscles of the Leg Flashcards
This compartment of the leg is the dorsiflexors or extensors and inverters. They are innervated by the deep fibular/peroneal nerve
Anterior Compartment
This compartment of the leg has the evertors and helps with plantar flexion. The muscles are innervated by the superficial fibular/peroneal nerve
Lateral Compartment
This group of muscles plantar flexes the foot and the toes and inverts the foot. They are innervated by the tibial nerve. Largest of the 3 compartments of the leg.
Posterior Compartment
Name the two components of the sciatic nerve
Commin Fibular Nerve (Lateral) (Deep and Superficial Divides) Tibial Nerve (Posteriorly)
Name the three superficial posterior leg muscles
Gastrocnemius
Soleus
Plantaris
The gastrocnemius and soleus together make up the
Triceps Surae
The most superficial muscle in the posterior leg, has 2 heads of origin and crosses 2 joints
Gastrocnemius
Origin and insertion of the gastrocnemius
Origin: Medial and lateral condyles of the femur
Insertion: Calcaneus via calcaneal tendon (achille’s tendon)
Innervation of the gastrocnemeus
Tibial Nerve
Action of the gastrocnemeus
Plantar flexion and flexes the leg
Muscle that lies deep to the grastrocnemeus, looks like a fish.
An antigravity muscle that acts with the extensors of the leg to maintain balance. Slow but strong plantar flexor
Soleus
Origin and insertion of the soleus
Origin: Head of the fibula, tibia
Insertion: Calcaneus via calcaneal tendon
Innervation of the soleus
Tibial nerve
Action of the soleus
Plantar flexion (no action on knee joint)
Which muscle of the triceps surae is involved in slow movement, or taking a stroll?
Which is for long jumping or rapid running movements?
Soleus
Gastrocnemeus
Small muscle whose tendon runs between soleus and gastrocnemeus , crosses 2 joints. Absent in about 10% of population
Plantaris
Origin and Insertion of the plantaris
Origin: Lateral condyle of the femur
Insertion: Calcaneus (not via tendon)
Innervation of the plantaris
Tibial Nerve
Action of the plantaris
Assists in knee flexion with gastrocnemeus
Plantar flexion at the ankle
Name the 4 muscles of the deep compartment of the posterior leg
Popliteus
Flexor Digitorum Longus
Flexor Hallucis Longus
Tibialis Posterior
The deep muscle located behind the knee in the popliteal fossa.
Popliteus
Origin and insertion of the popliteus
Origin: Lateral condyle of the femur
Insertion: Tibia
Innervation of the popliteus
Tibial nerve
Action of the popliteus
Flexes the leg
medially rotates the leg
Unlocks knee from fully extended position
One of the three vertically placed muscles in the leg, the most medial muscle. Usually the smallest of the three deep muscles
Flexor Digitorum Longus
Origin and insertion of the flexor digitorum longus
Origin: Tibia
Insertion: Distal phalanges of toes 2 3 4 5
Innervation of the flexor digitorum longus
Tibial Nerve
Action of the flexor digitorum longus
Plantar flexion
Inversion
Flex toes
The most laterally placed deep muscle, usually much larger than the flexor digitorum longus.
Used as the push off muscle during walking, running, and jumping
Flexor Hallucis Longus
Origin and insertion of the flexor hallucis longus
Origin: Fibula and interosseous membrane
Insertion: Distal phalanx of big toe
Innervation of the flexor hallucis longus
Tibial Nerve
Action
Plantar flexion
Inversion
Flex the great toe
“Toe off”
The deepest and centrally located muscle in the deep compartment between FDL and FHL
Tibialis Posterior
Origin and insertion of the tibialis posterior
Origin: Tibia, fibula, interosseous membrane
Insertion: Metatarsal 2,3,4
Innervation of the tibialis posterior
Tibial Nerve
Action of the tibialis posterior
Inversion
Plantar flexion
Adduction
Tom Dick and Harry , arrangement at the ankle medially to laterally
Tibialis posterior
Flexor Digitorum Longus
Flexor Hallucis Longus
The 3 tendons of the deep posterior muscles are held in place by…
Flexor Retinaculum
