Posterior Thigh Flashcards
What is the innervation of the posterior thigh muscles?
Tibial division of the sciatic nerve. EXCEPT for the short head of the biceps femoris which is innervated by the common fibular portion.
What muscle action do ALL of the posterior leg muscles participate in?
Leg flexion
What is the action of the semitendinosus muscle?
Extend thigh and flex leg and slightly medially rotate
What muscles insert on the pes anserinus?
Sartorius m, gracilis m, semitendinosus m
What is the action of the semimembranosus muscle?
Extend thigh and flex leg
What are the actions of the biceps femoris muscles?
LH - extend thigh and flex leg
SH- flex leg ONLY
What is the action of the adductor magnus (hamstring portion)?
Extends thigh
What joints are crossed with the adductor magnus (hamstring portion)?
Crosses hip but doesn’t cross knee
What are the borders of the popliteal fossa?
Superomedially- semimembranosus and semitendinosus
Superolaterally- biceps femoris
Inferolaterally and inferomedially - gastroc medial and lateral heads
What are the contents of the popliteal fossa?
nerves (in particular the tibial n right in the middle)
popliteal vein and LN
popliteal artery and branches
What special positional relationships happen within the popliteal fossa?
Superficial to deep:
nerves
popliteal vein and LN
popliteal artery and branches
What is the deepest structure in the popliteal fossa?
Popliteal artery
What are the components of the genicular anastomosis?
superior medial/superior lateral
inferior medial/ inferior lateral
Why is the descending branch of the lateral femoral circumflex artery important?
it is the connector of the cruciate anastomosis at the hip to the anastomosis at the knee. it travels down through the vastus lateralis and emerges lateral to the knee anastomosis with the superior lateral genicular artery. This way, if the nerve has been cut, will get blood to leg
what is the termination of the popliteal artery? Where does this bifurcation occur?
anterior and posterior popliteal artery. anterior goes front at the top of the interosseous membrane
when does the sciatic nerve develop into its two own independent nerves?
at the apex (top) of the popliteal fossa
How does the common fibular nerve leave the popliteal fossa? why is this important?
passes superficial to the head of the gastrocnemius m–>winds around neck and head of fibula–>becomes VERY superficial.
IT IS VERY PRONE TO INJURY.
Where does the common fibular nerve bifurcate?
deep to fibularis longus m where it becomes superficial fibular nerve and deep fibular nerve
from where does the sural cutaneous branch arise?
from the lateral sural cutaneous nerve
What is trochanteric bursitis?
inflammation of the trochanteric bursa
may result from repetitive actions such as climbing stairs while carrying heavy options or running on a steeply elevated treadmill
causes pain in the lateral thigh region
the pain can radiate down the iliotibial tract
Describe the cause of hamstring strain
these injuries are common in those who run and or kick hard. the violent muscular exertion required to excel in these sports may tear part of the proximal tendinous attachments of the hamstrings to the ischial tuberosity.
What are unique features of hamstring tear?
pain so bad that a person falls to the ground and writhes in pain. this usually is from inadequate warming up before practice or competition
How can avulsion (tearing away) of the ischial tuberosity at the proximal attachment of the biceps femoris and semitendinosus occur?
by forcible flexion of the hip with the knee extended like when kicking a football
What is compressed in piriformis syndrome? what population of people suffer from this condition?
the sciatic nerve; those that have excessive use of the gluteal region (ice skaters, cyclists, and rock climbers)
