The lateral head originates from a distinct facet on the upper lateral surface of the lateral femoral condyle where it joins the lateral supracondylar line.
At the knee, the facing margins of the two heads of the gastrocnemius form the lateral and medial borders of the lower end of the popliteal fossa.
In the upper leg, the heads of the gastrocnemius combine to form a single elongate muscle belly, which forms much of the soft tissue bulge identified as the calf.