Figure 1. Knee/Leg Extensors (Quadriceps)

The knee/leg extensors are a group of four muscles located in the anterior thigh region on both sides of the body. Their names are: 1) Vastus Rectus (a.k.a. Rectus Femoris) 2) Vastus Medialis 3) Vastus Lateralis 4) Vastus Intermedialis.