The quadratus femoris muscle is the most inferior of the deep group of muscles in the gluteal region (Fig. 6.45). It is a flat rectangular muscle below the obturator internus muscle and its associated gemellus muscles.
The quadratus femoris is attached at one end to a linear roughening on the lateral aspect of the ischium just anterior to the ischial tuberosity and at the other end to the quadrate tubercle on the intertrochanteric crest of the proximal femur.