The vastus intermedius muscle is located along the upper portion of the femur, which is also known as the thighbone. This muscle covers the front part of the femur and the side of the femur. It is directly underneath and ends at the rectus femoris muscle, which is part of the quadriceps cluster of muscles.
The muscle is closely related to the vastus medialis muscle and may look attached to that muscle. When the rectus femoris flexes, a small area is visible between the two muscles. The two muscles move in a contiguous line, but each is a separate muscle.
It is hard to stretch the muscle because of its location in the quadriceps; hip extension exercises are ineffective and massage therapy cannot reach the muscle. People with vastus intermedius muscle strain or other problems may require special surgery to repair the damage, or may be prescribed targeted exercises to progressively work out any strains.