The vastus medialis is the lowest of the quadriceps muscles. The quadriceps muscle group consists of four muscles: the rectus femoris, the vastus lateralis, the vastus intermedius, and the vastus medialis. These muscles form a large, fleshy mass that covers the front and sides of the femur (upper leg bone). They are the primary extensor of the knee. The vastus medialis is a bulging teardrop form located on the inner front corner of the lower thigh. It can be divided into two portions, the vastus medialis longus, which extends the knee, and the vastus medialis oblique.
