vastus lateralis, the largest of the four muscles of the quadriceps femoris group, situated on the lateral side of the thigh. It is a large, dense mass originating in a broad aponeurosis that is attached to the intertrochanteric line of the femur, the greater trochanter, the lateral lip of the gluteal tuberosity, and the lateral lip of the linea aspera. The fibers of the muscle are gathered to form a strong aponeurosis that converges to become a flat tendon before inserting under the patella and onto the lateral condyle of the tibia. The muscle functions to help extend the leg. Compare rectus femoris, vastus intermedius, vastus medialis. See also quadriceps femoris.
