Politeal region and Posterior leg Flashcards
What are the boundaries of the popliteal fossa?
biceps femoris
semitendinosus and semimembranosus
gastrocnemius
skin/fascia
What are the contents of the popliteal fossa?
popliteal artery and vein
common fibular and tibial nerves
fat and lymph nodes
small saphenous vein
What is the popliteal artery a continuation of? Where does the name change occur?
It’s a continuation of the femoral artery
name changes at the adductor hiatus
What type of fracture will put the pepliteal artery (and tibial nerve) at risk?
dstal femur fractures
The popliteal artery gives rise to what branches that supply the knee?
the genicular arteries:
superior medial
superior lateral
inferior medial
inferior lateral
Where does the small saphenous vein begin?
What does it empty into?
starts on the lateral side of the dorsal venous network of the foot
passes behind the lateral malleolus up the back of the leg
empties into the pepliteal vein
What nerve accompanies the small saphenous vein?
the sural vein
How can the common fibular nerve be injured?
from fracture of the neck of the fibula or from pressure from a cast
this is because the common fibular nerve winds around the head of the fibula in the subcutaneous tissue
Under cover from the fibularis longus, the common fibular nerve divides into what?
the superficial and deep fibular nerves
THe sural nerve is a combination of what two branches?
the medial sural cutaneous nerve (from the tibial nerve) and the lateral sural cutaneous nerve (from the common fibular nerve) via the sural communicating branch
What cutaneous nerve supplies the back of the pepliteal region?
the posterior cutaneous nerve of the thigh
What forms the compartments of the leg?
the anterior and posterior crurual intermuscular septa (as extensions of the deep crurual fascia) and the tibia
What are the three compartments of the leg called?
anterior
lateral
posterior (deep and superficial)
What divides the anterior and posterior compartments of the leg?
the itnerosseous membrane between the tibia and the fibula
What divides the posterior compartment into deep and superficial areas?
the transvers intermuscular septum
What are the three eg muscles in the superficial posterior group?
gastrocnemius
plantaris
soleus
Where does the gastrocnemius originate? Insert?
the lateral head inserts on the lateral condule of the femur while the medial head is on the pepliteal surface of the femor, superior to the medial condyle
it inserts on the powerior surface of the calcanius via the calcaneal tendon
What does the gastrocnemius do?
it flexes the knee joint and plantarflexes the foot joint at the ankle
what innervates the gastrocnemius?
tibial nerve
Where does the plantaris originate and insert?
orginates on the inferior end of the lateral supracondylar line of the femor, as well as the oblique popliteal ligament
it inserts on the posterior surface of the calcaneus - but probably not thorugh the calcaneal tendone
What is the plantaris analogous to in the forearm?
palmarus longus
What does the plantaris do?
is plantarflexes the foot at the anke joint and weakly flexes the knee joint (used to tendon grafts since it’s so redundant)
Wht nerve innervates the plantaris?
tibial nerve
What is the plantaris tenodn often mistaken for?
the tibial nerve
Where is the soleus located?
deep to the gastrocnemius
What does the soleus do?
it’s a slow platnarflexor of the ankle joint - an antigravity muscle that contracts alternately with the extensor muscles of the leg to maintain balance
What nerve innervates the soleus?
tibial nerve
What are the 4 muscles of the posterior deep grooup?
popliteus
flexor digitorum longus
tibialis posterior
flexor hallucis longus
What nerve innervates the posterior deep group of muscles?
the tibial nerve
Where does the popliteus originate and insert?
originates just above the soleus muscle and crosses thorugh the knee between the lateral meniscus and fibular collateral ligament to insert on the femur
What is the interesting function of the popliteus?
It flexes the knee joint and unlocks the knee by lateral rotation of the femur on the tibia
What is the strongest plantarflexor? Is it also the fastest?
the soleus is the strongest, but it’s slow - the gastrocnemius is the fast one
Does the soleus act on the knee joint?
no - diesn’t cross it, so only works at the ankle joint
In the proximal leg, what is the order (from medial to lateral) of the deep compartment?
- flexor digitorum longus
- tibialis posterior
- flexor hallucis longus
Dick, Tim, Harry
Where does the flexor digitorum longus insert?
it splits into 4 tendons that insert on the base of the distal phalanges of the lateral four toes
WHere does the tibialise poserior insert?
it inserts into the tarsal bones and base of metatarsals, running along the interosseous membrane
Where does the flexor hallucis longus insert?
on the distal phalanx of the great toe
What does the flexor digitorum lungus do? WHat does the tibialis posterior do? WHat does the flexor hallucis longus do?
FDL: plantarflexes the ankle joint and flexes lateral 4 digits
the tibialis posterior plantarflexes the ankle joint and inverts the foot.
the FHL flexes the great toe
Down at the ankle, the deep leg muscles cross under what structure? In what order now?
under the flexor retinaculum
the tibialis posterior crosses under the flexor digtorum longus, so the order is…
Tim’s Dick And Now Harry’s
tibialis posterior
flexor digitorum longus
tibial artery
tibial nerve
flexor hallucis longus
How does the tibial nerve enter the posterior compartment of the leg?
WHat does it run between?
it enters the posterior compartment between the heads of the gastrocnemius
it runs between the deep and superficial muscle groups, deep to the transverse crurual intermuscular septum
The tibial nerve will divide into what two branches in the sole of the foot?
the medial and lateral plantar nerves
What is the plantar reflex testing. What is normal? WHat is abnormal?
the plantar reflex (of L4-S2) is a deep tendon reflex
you stroke the lateral aspect of the sole of the foot from heel to great toe
normal is curling the toe slightly
abnormal is a Babinski’s sign - slight flaying and extension of the great toe
How is the calcaneal tendon reflex tested? What’s normal?
You strike the achilles tendon with a reflex hammer
normal response is plantarflexion of the ankle joint
In regards to the calcaneal tendon reflex, the following would suggest what?
absent
delayed
reduced
absent = sciatic nerve pathology
delayed = hypothyroidism
reduced = peripheral neuropathy
THe tibial nerve is hard to injure because of it’s deep location in the popliteal foss and posterioa compartment, but how can it be? WHat would happen?
deep lacerations
posterior dislocation of the knee joint
you’d lose the function of the posterior compartment of the leg and the intrinsic muscles of the sole of the foot
popliteal artery divides into what?
the posterior and anterior tibial artery
What does the posterior tibial artery divide into?
the fibular artery (peroneal artery)
and the medial/lateral plantar arterial branches to the foot
What holds the deep flexor muscle tendons in place in the ankle?
the flexor retinaculum
Where does the flexor retinaculum span from?
from the medial malleolus to the calcaneus
What is the most severe, acute muscualr problem of the leg?
calcaneal tendon rupture
can occur in those who have a hx of tendinitis of the tendon - or just as an acute injury
What happens in tennis leg?
is a muscle strain of the medial head of the gastrocnemius
occures in middle aged men who try to play tennis - full extension fo the knee with dorsiflexion of the ankle at the same time
What is a baker’s cyst?
Where do they occur?
It’s a popliteal cyst
it occurs when any sort of inflammation affects the knee joint and causes effusion of synovial fluid
Popliteal aneurysms are often asymptomatic, but what’s the main concern with them?
that clots in the aneurysm will interfere with blood flow to the lower extremity - amputation may be the result so surgical repair is often called for even though the aneurysm is unlikely to rupture
Which leg bone bears the weight of the body (and it bigger)?
the tibia
Which leg bone articulates with the femur
the tibia (fibula does not participate)
What lies between the lateral condyle and medial condyle of the tibia?
the tibial plateau
THe interosseous membrane between the fibula and tibia is what type of joint?
syndesmosis
the knee joint involves a hinge joint between the ___ and ___
and a plane/gliding joint between the ___ and the ____
hunge between the femur and tibia
plane between the femur and the patella
Which bone of the foot do the two leg bones articulate with in a hinge joint?
the talus
