Muscles of Anterior Thigh

Question 1

Sartorius

Answer 1

O: ASIS and sup. part of inf. notch

I: Sup. part of medial surface of tibia

A: abduction, medial rotation, flexion of hip; keeps knee extended; steadies trunk on thigh

N: superior gluteal n (L4-S1)

Question 2

Rectus Femoris

Answer 2

O: AIIS, groove superior to acetabulum

I: base of patella via patellar ligament to tibial tuberosity

A: extension of leg at knee; steadies hip joint and helps iliopsoas flex thigh

N: femoral n. (L2-4)

Question 3

Vastus Lateralis

Answer 3

O: greater trochanter, lateral lip of linea aspera

I: base of patella and via patellar ligament to tibial tuberosity

A: extends leg at knee

N: femoral n. L2-4

Question 4

Vastus Intermedius

Answer 4

O: Ant. and lat. surfaces of body of femur

I: base of patella and patellar ligament to tibial tuberosity

A: extends leg at knee

N: femoral n L2-4

Question 5

Vastus Medialis

Answer 5

O: intertrochanteric line and med. lip of linea aspera; spiral line

I: Base of patella via patellar tendon to tibial tuberosity

A: extension of leg at knee

N: femoral n. L2-4

Question 6

Psoas Major

Answer 6

O: TP of lumbar vert. sides of bodies (T12-L5)

I: strong tendon into lesser trochanter

A: VC fixed, flexes thigh with iliacus;
with thigh fixed acting alone, lateral flexion of VC;
Acting inferiorly with other side and iliacus flexes the trunk
Balances trunk

N: Ventral Rami of L1-3(4)

Question 7

Iliacus

Answer 7

O: sup. 2/3 of iliac fossa, ala of sacrum, and ant. SI ligament

I: tendon of psoas, lesser trochanter, and shaft of femur inf. to lesser trochanter

A: Flexes thigh and trunk depending on whether VC or thigh is fixed

N: femoral n. L2-4