Quadriceps

The quadriceps is the most voluminous muscle in the anterior region of the thigh and, as its name can be inferred, is composed of four heads:

• rectus femoris
• vast media
• broad lateral
• large intermediate

Three of these muscles are monoarticular: vast medial (or internal), vast lateral (or external), vast intermediate

Only one muscle is biarticular: rectus femoris (or anterior).

It is superficially crossed by the sartorius. In the middle and lower part it is covered by the femoral fascia and relates to the posterior thigh muscles and the adductors

The four heads converge at the bottom and at knee level they collect in an apparently common tendon, but formed by the overlapping of three laminae.

The superficial lamina is the continuation of the femoral rectum.

The intermediate one belongs to the vast medial and lateral.

The deep one at the vast middle.

At the level of the patella, most of the tendon fibers find insertion in the patella and some bundles are fixed to the infraglenoid margin of the tibia.

Distal to the patella these tendinous bundles continue in the patellar ligament and are inserted into the tibial tuberosity.

Its main action is to extend the knee; the rectus femoris also participates in the flexion of the thigh.

It is innervated by the femoral nerve L2-L4.