Quadriceps Muscle

Last update: Sep 8th, 2022

Introduction

The quadriceps muscle, which derives its name from the Latin word for four-headed, is in practice a group of four muscles; rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis. It is the largest muscle in the human body, and the sole extensor of the knee joint.

In this tutorial, we will learn about the insertion, origin, innervation and action of these four muscles.

An illustration showing anterior thigh muscles

An illustration showing anterior thigh muscles with Quadriceps Muscle labeled and highlighted with green

Rectus femoris muscle

Attachments

Origin (proximal attachment):

Anterior inferior iliac spine and supracetabular groove of the ilium

Insertion (distal attachment):

Tibial tuberosity (via patellar ligament)

The anterior view of the thigh, pelvis and lower section of the vertebral column. The only visible labelled muscle is Rectus Femoris

The anterior view of the thigh, pelvis and lower section of the vertebral column showing the origin of Rectus Femoris at the anterior inferior iliac spine and ilium above the acetabulum and insertion at quadriceps tendon to base of patella and onto tibial tuberosity via the patellar ligament.

Vastus lateralis muscle

Attachments

Origin (proximal) attachments:

Greater trochanter of femur, intertrochanteric line, gluteal tuberosity and lateral aspect of linea aspera.

Insertion (distal) attachments:

Just like all the other three muscles, vastus lateralis inserts into the tibial tuberosity via the patellar ligament and also into the patella itself.

An image showing the Vastus Lateralis Muscle attached to the lower limb

An image showing the Origin and Insertion of the Vastus Lateralis Muscle on the lower limb

Vastus medialis muscle

Attachments

Origin (proximal) attachments:

Intertrochanteric line, spiral line and linea aspera, and the medial lip of linea aspera of femur

Insertion (distal) attachments:

Tibial tuberosity (via patellar ligament) and the patella itself

An image showing the Vastus Medialis Muscle attached to the lower limb

An image showing the Origin and Insertion of the Vastus Medialis Muscle on the lower limb

Vastus intermedius muscle

Attachments

Origin (proximal) attachments:

Anterior and lateral surface of the femoral shaft.

Insertion (distal) attachments:

Tibial tuberosity (via patellar ligament) and the patella itself

An image showing the Vastus Intermedius Muscle attached to the lower limb

An image showing the Origin and Insertion of the Vastus Intermedius Muscle on the lower limb

Innervation of quadriceps femoris

Femoral nerve (L2-L4).

Action of quadriceps femoris

As mentioned in the introduction of this tutorial, quadriceps femoris extends the leg at the knee joint. It’s also worth noting that the rectus femoris also helps flexing the thigh at the hip joint.