Quadratus femoris muscle

The quadratus femoris is a flat, quadrilateral skeletal muscle. Located on the posterior side of the hip joint, it is a strong external rotator and adductor of the thigh, but also acts to stabilize the femoral head in the acetabulum. The quadratus femoris is used in Meyer's muscle pedicle grafting to prevent avascular necrosis of femur head.