Thigh & Knee Muscles

origin of femoral n

L2, L3, L4

origin of obturator n

L2, L3, L4

origin of superior gluteal n

L4, L5

origin of inferior gluteal n

L4, L5, S1

origin of sciatic n

L4, L5, S1, S2, S3

femoral triangle contents

NAVaL femoral N, femoral A, femoral V, Lymph nodes + saphenous n (br of femoral n), deep femoral a & proximal brr, saphenous opening, great saphenous v

vastus intermedius

PA: anterior femoral shaft DA: tibial tuberosity via quadriceps tendon Action: extend leg N: femoral n A: femoral a

rectus femoris

PA: anterior inferior iliac spine DA: tibial tuberosity via quadriceps tendon Action: flex thigh, extend leg N: femoral n A: femoral a

sartorius

PA: anterior superior iliac spine DA: medial tibia via pes anserinus Action: flex, abduct, and laterally rotate thigh; flex and medially rotate leg N: femoral n A: superficial femoral a

iliacus

PA: iliac crest, iliac fossa, sacral ala DA: lesser trochanter Action: hip flexion, lateral flexion of trunk N: femoral n A: femoral a

adductor brevis

PA: inferior pubic ramus DA: pectineal line, proximal linea aspera Action: adduct thigh N: obturator n A: obturator a

adductor magnus

PA: inferior pubic ramus, ischial ramus, ischial tuberosity DA: gluteal tuberosity, linea aspera, medial supracondylar line, adductor tubercle Action: adduct thigh, flex & extend thigh N: obturator n, tibial part of sciatic n A: obturator a

biceps femoris long head

PA: ischial tuberosity DA: fibular head Action: extend thigh, flex leg, laterally rotate leg N: tibial part of sciatic n A: deep femoral a

semimembranosus

PA: ischial tuberosity DA: medial condyle tibia Action: extend thigh, flex leg, medially rotate leg N: tibial part of sciatic n A: deep femoral a

semitendinosus

PA: ischial tuberosity DA: medial tibia via pes anserinus Action: extend thigh, flex leg, medially rotate leg N: tibial part of sciatic N A: deep femoral A

vastus lateralis

PA: lateral lip of linea aspera DA: tibial tuberosity via quadriceps tendon Action: extend leg N: femoral n A: femoral a

biceps femoris short head

PA: linea aspera DA: fibular head Action: extend thigh, flex leg, laterally rotate leg N: common fibular part of sciatic N A: deep femoral a

vastus medialis

PA: medial lip of linea aspera DA: tibial tuberosity via quadriceps tendon Action: extend leg N: femoral n A: femoral a

obturator externus

PA: obturator membrane, margins of obturator foramen DA: trochanteric fossa Action: lateral rotation of thigh N: obturator n A: obturator a

adductor longus

PA: pubic body DA: medial linea aspera Action: adduct thigh N: obturator n A: obturator a

gracilis

PA: pubic body, inferior pubic ramus DA: medial tibia via pes anserinus Action: adduct thigh, flex & medially rotate leg N: obturator n A: deep femoral a

pectineus

PA: superior pubic ramus DA: pectineal line Action: adduct thigh, flex thigh, medially rotate thigh N: obturator n, femoral n A: obturator a, deep femoral a

psoas major

PA: vertebrae T12-L4/L5 DA: lesser trochanter Action: hip flexion, lateral flexion of trunk N: lumbar spinal n A: femoral a

adductor canal floor

adductor longus, adductor brevis

anterior cruciate ligament

attaches anteriorly to tibia and posteriorly to femur, prevents anterior displacement of tibia (posterior displacement of femur when leg fixed)

posterior cruciate ligament

attaches posteriorly to tibia and anteriorly to femur, prevents posterior displacement of tibia (anterior displacement of femur when leg is fixed)

pes anserinus

attachment site for sartorius (ant thigh), gracilius (med thigh), semitendinosus (lat thigh)

medial compartment

contains muscles that primarily adduct the thigh N: obturator n A: obturator & deep femoral aa

anterior compartment of thigh

contains muscles that primarily extend the knee &/or flex the hip N: femoral n A: femoral a

posterior compartment

contains muscles that primarily flex the knee &/or extend the hip N: sciatic n A: deep femoral a

femoral artery branches

deep femoral a (supplies quadriceps femoris mm)

external iliac artery branches

femoral a (after passing inguinal ligament), popliteal a (after passing adductor hiatus)

medial meniscus

fibrocartilage located at the knee, between medial femoral condyle and medial condyle of tibia

lateral meniscus

fibrocartilage located at the knee, between the lateral femoral condyle and lateral condyle of tibia

cutaneous nerves of anterior thigh

iliohypogastric n, gentiofemoral n, ilioinguinal n, lateral femoral n, anterior femoral cutaneous n

patellar tendon

inferior portion of the quadriceps tendon, within which the patella sits

terrible triad of knee

injury of ACL, MCL, medial meniscus; caused when knee is forced to rotate while leg is fixed, leading to anteromedial displacement, most often result from posterolateral trauma to knee while foot is planted/leg fixed

patella

largest sesmoid bone in the body, forms within the quadriceps tendon

deep femoral a branches

lateral femoral circumflex a & medial femoral circumflex a, which anastomose with each other to provide blood supply to head of femur

lateral collateral ligament

ligament that attaches to femur and fibula, maintains stability of the lateral aspect of the knee joint, prevents excessive adduction

medial collateral ligament

ligament that attaches to femur and tibia, maintains stability of the medial aspect of the knee joint, prevents excessive abduction

cutaneous nerves of distal medial thigh

obturator n

iliopsoas

pair of muscles (psoas major, iliacus) that have common insertion & action

femoral triangle floor

pectineus (medially), iliopsoas (laterally)

cutaneous nerves of posterior thigh

posterior femoral cutaneous n, lateral femoral cutaneous n

fascia lata

proper name for deep fascia of thigh, has 3 investing septa (lateral, medial, posterior) that anchor it deep to the femur

anterior compartment of thigh

quadriceps femoris = rectus femoris, vastus lateralis, vastus medialis, vastus intermedius; sartorius

adductor canal roof

sartorius

femoral triangle roof

skin & fascia lata

femoral triangle boundaries

superior = inguinal canal/ligament, lateral = sartorius, medial = adductor longus

internal iliac artery branches

superior gluteal a (above piriformis), inferior gluteal a (below piriformis), obturator n

adductor canal boundary

vastus medialis