L7: Anterior Thigh Muscles

Question 1

What are the Muscles of the Anterior Thigh?

Name 5, but note the Quadricep Muscles are also anterior thigh muscles

Answer 1

Pectineus
Sartorius
Psoas major
Iliacus
Quadriceps femoris

Question 2

What muscles are included in the Quadriceps femoris?

Answer 2

Rectus femoris
Vastus lateralis
Vastus medialis
Vastus intermedius

Question 3

Pectineus

Answer 3

Origin: Superior ramus of pubis

Insertion: Pectineal line of femur, just inferior to the lesser trochanter

Innervation: Femoral nerve (L2, L3)

Function: Adducts, medially rotates and flexes hip joint

Question 4

Sartorius

Answer 4

Origin: Anterior superior iliac spine and superior part of notch inferior to it

Insertion: Superior part of medial surface of tibia (as part of pes anserinus)

Innervation: Femoral nerve (L2, L3)

Function: Flexes, abducts, and laterally rotates hip joint; flexes knee joint

Question 5

Iliopsoas (Psoas Major)

Answer 5

Origin: Sides of T12–L5 vertebrae and discs between them; transverse processes of all lumbar vertebrae

Insertion: Lesser trochanter of femur

Innervation: Anterior rami of lumbar nerves (L1, L2, L3)

Function: flexes hip joint and in stabilizing this joint; psoas major is also a postural muscle that helps control deviation of the trunk and is active during standing.

Question 6

Iliacus

Answer 6

Origin: Iliac crest, iliac fossa, ala of sacrum, and anterior sacroiliac ligaments

Insertion: Tendon of psoas major, lesser trochanter, and femur distal to it

Innervation: Femoral nerve (L2, L3)

Function: Flexes hip joint, postural muscle active during standing

Question 7

Rectus femoris

Answer 7

Origin: Anterior inferior iliac spine and ilium superior to acetabulum

Insertion: quadriceps tendon to the base of the patella; patellar ligament to tibial tuberosity;

Innervation: Femoral nerve (L2, L3, L4)

Function: Extend knee joint; rectus femoris also stabilizes hip joint and helps iliopsoas flex hip joint.

Question 8

Vastus Lateralis

Answer 8

Origin: Greater trochanter and lateral lip of linea aspera

Insertion: Via common tendinous (quadriceps tendon) to the base of the patella; indirectly via patellar ligament to tibial tuberosity

Innervation: Femoral nerve (L2, L3, L4)

Function: Extend knee joint

Question 9

Vastus Medialis

Answer 9

Origin: Intertrochanteric line and medial lip of linea aspera

Insertion: Via common tendinous (quadriceps tendon) to the base of the patella; indirectly via patellar ligament to tibial tuberosity

Innervation: Femoral nerve (L2, L3, L4)

Function: Extend knee joint

Question 10

Vastus Intermedius

Answer 10

Origin: Anterior and lateral surfaces of the shaft of the femur

Insertion: Via common tendinous (quadriceps tendon) to the base of the patella; indirectly via patellar ligament to tibial tuberosity

Innervation: Femoral nerve (L2, L3, L4)

Function: Extend knee joint

Question 11

Psoas Minor

Answer 11

Origin: sides of the bodies and discs of T12 and L1

Insertion: Iliopubic eminence (pelvic brim) and inguinal ligament

Function: Assists in flexion of the lumbar spine

Nerve Supply:
Typically innervated by the anterior rami of L1 spinal nerve (T12-L5)

Question 12

Quadratus Lumborum

Answer 12

Origin:
Iliac crest (posterior part) and iliolumbar ligament
​
Insertion:
Transverse processes of lumbar vertebrae (L1-4) and the 12th rib
​
Function:
Bilateral contraction extends the lumbar spine, unilaterally contracts to laterally flex the spine (bends the trunk to the side), and assists in forced respiration
Like a natural weight belt
​
Nerve Supply:
Anterior rami of lower thoracolumbar nerves (T12-L4) (not too concerned with nerve supply of abdominal muscles - Tim)