Quadricep femoris (quad ri sep/fem or us)

(comprised of four heads: rectus femoris, vastus lateralis, vastus medialus, and vastus intermedius)

O:  rectus femoris: shaft of the ilium

Vastus muscles: lateral, medial and anterior surface of the femoral shaft

I:  patella, proximal tibia, tibial tuberosity

A: Stifle extension

Rectus femoris also flexes the hip