Muscles Of The Anterior Compartent Of The Thigh

Question 1

Muscles of the anterior compartment of the thigh

Answer 1

The three major muscles in the anterior thigh are the pectineus, sartorius and quadriceps femoris. In addition to these, the end of the iliopsoas muscle passes into the anterior compartment.

Question 2

Innervation of muscles of the anterior compartment of the thigh

Answer 2

Femoral nerve (L2-L4)

Question 3

General action of muscles of the anterior compartment of the thigh

Answer 3

Act to extend the leg at the knee joint

Question 4

Iliopsoas

Answer 4

The iliopsoas is actually two muscles, the psoas major and the iliacus. They originate in different areas, but come together to form a tendon, hence why they are commonly referred to as one muscle.

Question 5

Iliopsoas Attachments

Answer 5

The psoas major originates from the lumbar vertebrae, and the iliacus originates from the iliac fossa of the pelvis. They insert together onto the lesser trochanter of the femur.

Question 6

Iliopsoas Actions

Answer 6

Flexes the thigh at the hip joint.

Question 7

Iliopsoas Innervation

Answer 7

The psoas major is innervated by anterior rami of L1-3, while the iliacus is innervated by the femoral nerve.

Question 8

What is the main extensor of the knee?

Answer 8

Quadriceps femoris

Question 9

Quadriceps femoris muscles

Answer 9

Vastus Lateralis, Vastus Intermedius, Vastus Medialis, Rectus Femoris

Question 10

Quadriceps femoris distal attachment

Answer 10

The muscles that form the quadriceps femoris unite proximal to the knee and attach to the patella via the quadriceps tendon.

Question 11

What attaches the patella to the tibial ligament?

Answer 11

Patella ligament

Question 12

Vastus Lateralis Proximal attachment

Answer 12

Originates from the greater trochanter and the lateral lip of linea aspera.

Question 13

Vastus Lateralis Actions

Answer 13

Extends the knee joint and stabilises the patella.

Question 14

Vastus Lateralis Innervation

Answer 14

Femoral nerve.

Question 15

Vastus Intermedius Proximal attachment

Answer 15

Anterior and lateral surfaces of the femoral shaft.

Question 16

Vastus Intermedius Actions

Answer 16

Extends the knee joint and stabilises the patella.

Question 17

Vastus Intermedius Innervation

Answer 17

Femoral nerve.

Question 18

Vastus Medialis Proximal attachment

Answer 18

The intertrochanteric line and medial lip of the linea aspera.

Question 19

Vastus Medialis Actions

Answer 19

Extends the knee joint and stabilises the patella, particularly due to its horizontal fibres at the distal end.

Question 20

Vastus Medialis Innervation

Answer 20

Femoral nerve.

Question 21

Rectus Femoris Proximal attachment

Answer 21

Originates from the ilium, just superior to the acetabulum.

Question 22

Rectus Femoris Actions

Answer 22

The only muscle of the quadriceps to cross both the hip and knee joints. It flexes the thigh at the hip joint, and extends at the knee joint.

Question 23

Rectus Femoris Innervation

Answer 23

Femoral nerve.

Question 24

Sartorius Attachments

Answer 24

Originates from the anterior superior iliac spine, and attaches to the superior, medial surface of the tibia.

Question 25

Sartorius Actions

Answer 25

At the hip joint, it is a flexor, abductor and lateral rotator. At the knee joint, it is also a flexor.

Question 26

Sartorius Innervation

Answer 26

Femoral nerve.

Question 27

Pectineus Attachments

Answer 27

It originates from the pectineal line on the anterior surface of the pelvis, and attaches to the pectineal line on the posterior side of the femur, just inferior to the lesser trochanter.

Question 28

Pectineus Actions:

Answer 28

Adduction and flexion at the hip joint.

Question 29

Pectineus Innervation

Answer 29

Femoral nerve. May also receive a branch from the obturator nerve.