The vastus medialis is one of the four muscles which make up the quadriceps. It is located to the inner region of the thigh close to the knee, and is commonly referred to as the “tear drop” muscle by bodybuilders due to its shape.
As with the other quadriceps muscles, the vastus medialis is recruited strongly during the extension of the knee. The squat is widely considered the king of the lower body exercises, and it is indeed a great choice for the development of the vastus medialis, and the other quadriceps muscles. The quadriceps can also be targeted, in an isolated manner, with leg extensions.
Strengthening of the vastus medialis is important for ensuring a stable knee joint.