15: Posterior Leg Flashcards
Which foot bone has a groove for the flexor hallucis longus tendon?
Talus
What two bones does the calcaneus articulate with?
Talus, cuboid
Sustentaculum tali
A shelf-like projection on the calcaneus that provides support for the talus
What runs in the groove of the sustentaculum tali?
Flexor hallucis longus
Five bones the navicular articulates with
Talus, 3 cuneiforms, cuboid
What muscle attaches to the navicular tuberosity?
Tibialis posterior
Four leg compartments formed by crural fascia
Anterior, lateral, posterior (superficial and deep)
Four shared structures in each leg compartment
Function, nerve, artery, vein
What septa divides posterior compartment into superior and deep?
Transverse septa
Three superficial posterior leg muscles
- Gastrocnemius
- Soleus
- Plantaris
Gastrocnemius: medial and lateral head origin
Medial: popliteal surface above medial femoral condyle
Lateral: lateral femoral condyle
Which head of gastrocnemius is a lil larger and extends a lil further?
Medial head
Common insertion for superficial posterior muscles
calcaneus via calcaneus tendon
Which muscle in the leg may have a fabella close to the origin
Lateral head of gastrocnemius
Fabellar stress fracture
Can occur after total knee replacements
Gastrocnemius action
Plantarflexion, leg flexion
Triceps surae
Soleus + two heads of gastrocnemius
Soleus O
Soleal line of tibia, posterior head of fibula
Soleus action
Plantarflexion
Plantaris presence
Is small and often absent
Where does the long tendon of the plantaris run?
Between gastrocnemius and soleus
Plantaris origin
Lateral end of lateral supracondylar line
Plantaris
Weak plantarflexion, leg flexion - but mostly proprioceptive for foot position
What can the plantaris tendon be used for?
Reconstructive hand surgery
Plantaris rupture: susceptible populations
Basketball players, sprinters, dancers
Four deep posterior leg muscles
- Popliteus
- Flexor hallucis longus
- Flexor digitorum longus
- Tibialis posterior
Popliteus relation to plantaris
Deep to plantaris
Popliteus O and I
O: posterior tibia
I: lateral femoral condyle and lateral meniscus
Popliteus A (two things
Weak flexor, unlocks extended leg by laterally rotating femur on stationary tibia
Popliteus relevance with the knee joint and popliteal fossa
- Separates LCL from lateral meniscus
2. Inferior floor of popliteal fossa
Largest deep posterior muscle
Flexor hallucis longus
Flexor hallucis longus O and I
O: inferior posterior fibula
I: base of distal phalanx of great toe
Where does flexor hallucis longus approach great toe at?
Between sesamoid bones in tendon of the flexor hallucis brevis
Flexor hallucis longus A
Great toe flexion, plantarflexion
Flexor digitorum longus relation to soleus
Deep to soleus
Flexor digitorum longus O and I
O: posterior tibia
I: distal phalanx base of lateral four digits
Path of the flexor digitorum longus tendon
Posterior to tibialis posterior -> diagonally in sole of foot, superficial to FHL tendon -> divides into four tendons for each lateral digit
Flexor digitorum longus action
Flexes lateral four digits, plantarflexion
Deepest posterior crural muscle
Tibialis posterior
Tibialis posterior O and I
O: interosseous membrane, posterior tibia and fibula
I: navicular tuberosity, cuneiforms, 204 metatarsal bases
Which two muscles is the tibialis posterior between?
FDL, FHL
Tibialis posterior action
Foot inversion, plantarflexion
Innervation to all posterior leg muscles
Tibial N
What does the tibial N run with?
Posterior tibial A and V
Where does the tibial nerve pass deep to the flexor retinaculum?
Between medial malleolus + calcaneus
Tibial N dividies into what?
Medial + lateral plantar N’s
Two superficial nerves to the posterior leg
- Medial sural cutaneous N
2. Lateral sural cutaneous N
What gives off medial and lateral sural cutaneous N’s?
Medial sural: tibial N
Lateral sural: common fibular N
What does the medial sural cutaneous N run with?
Small saphenous V
Artery to the posterior compartment
Posterior tibial A
Posterior tibial A relation to Tibialis posterior
Posterior to tibialis posterior
Largest branch of posterior tibial A
Fibular A
What does the fibular A anastomose with in the foot?
Anterior lateral malleolar A
What does the fibular A supply?
Posterolateral leg
Two terminal branches of posterior tibial A
Medial plantar A, lateral plantar A
How to palpate posterior tibial
Pt relaxes legs and inverts feet to relax flexor retinaculum - can palpate it deep to flexor retinaculum on posterior surface of medial malleolus
A condition where one would want to palpate the posterior tibial A
Occlusive peripheral arterial disease
Occlusive peripheral arterial disease
Ischemia of legs due to narrowing of arteries -> leg cramps and pain during walking
Do genicular A’s supply muscles?
No!
Superior medial and lateral geniculars: relation to gastrocnemius
Just superior to gastrocnemius origin
Inferior medial genicular A relation to gastrocnemius
Deep to medial head of gastroc
Inferior lateral genicular A relation to plantaris and popliteus
Deep to plantaris, superficial to popliteus
Leg comparment syndrome
Trauma in leg can cause hemorrhage, edema, and inflammation in a given compartment -> pressure, ischemia, and permanent injury
Possible treatment for leg compartment syndrome
Fasciotomy
Fibular trochlea
Ridge on lateral calcaneus for fibularis muscle insertion
Most lateral bone in the distal row of the tarsus
Cuboid
Five bones that articulate with the cuboid
Calcaneus, 4th and 5th metatarsals, navicular, lateral cuneiform
Cuboid sulcus
Groove in cuboid for fibularis longus