"Quads" redirects here. For other uses see Quad

It is subdivided into separate portions, which have received distinctive names.

• Rectus femoris occupies the middle of the thigh, covering most of the other three quadriceps muscles. It originates on the ilium. It is named from its straight course.
• The other three lie deep to rectus femoris and originate from the body of the femur, which they cover from the trochanters to the condyles:
• Vastus lateralis is on the lateral side of the femur.
• Vastus medialis is on the medial side of the femur.
• Vastus intermedius lies between vastus lateralis and vastus medialis on the front of the femur.

All four parts of the quadriceps muscle attach to the patella via the quadriceps tendon.

The quadriceps is also involved in Lombard's Paradox.

Actions

All four quadriceps are powerful extensors of the knee joint. They are crucial in walking, running, jumping and squatting. Because rectus femoris attaches to the ilium, it is also a flexor of the hip. This action is also crucial to walking or running as it swings the leg forward into the ensuing step.

Additional images

External links

• Anatomy of the Quadriceps Muscles - Fitstep.com