Its tendon often joins with the tendons of the superior gemellus, inferior gemellus, and obturator internus muscles prior to insertion.
Moving from the inferior-most to the superior-most, they are: the tendon of the obturator externus muscle, the obturator internus, the superior gemellus and inferior gemellus.
Along its course, quadratus is aligned edge to edge with the inferior gemellus above and the adductor magnus below, so that its upper and lower borders run horizontal and parallel.