Muscles of Anterior Compartment of the Thigh

Question 1

What are the muscles of the anterior compartment of the thigh?

Answer 1

Flexors of the thigh (hip):

• Pectineus
• iliopsoas (made up of psoas major, psoas minor (in 40% of people) and iliacus)
• Sartorius
• Rectus femoris

Extensors of the leg (knee) = quadriceps femoris:

• vastus lateralis
• vastus medialis
• vastus intermedius
• rectus femoris

Question 2

What muscle is this?

Answer 2

Pectineus

Question 3

What is the longer muscle?

What is the shorter muscle?

What is sometimes also present?

Answer 3

Longer = Psoas major muscle

shorter = iliacus muscle

Psoas minor - smaller muscle on top of psoas major

Question 4

Name this muscle

Answer 4

Sartorius

Question 5

Name each of the muscles?

Answer 5

rectus femoris - blue
vastus lateralis - yellow
vastus intermedius - green
vastus medialis - red

Question 6

What is the nerve supply to all muscles in the anterior compartment of the thigh?

Answer 6

Femoral nerve (L2, 3, 4) except iliopsoas which is innervated by anterior rami of lumbar spinal nerve (L1, 2 and 3)

Question 7

Actions of quadriceps femoris?

Answer 7

All = extension of knee

Rectus femoris also flexes hip

Question 8

Actions of muscles of anterior compartment of the thigh that aren’t quadriceps femoris?

Answer 8

Flexors of the thigh at the hip

Sartorius also flexes the knee