Origin Lateral margin of obturator ring above ischial tuberosity Insertion Quadrate tubercle and adjacent bone of intertrochanteric crest of proximal posterior femur Action Rotates the hip laterally; also helps adduct the hip Innervation Quadratus femoris branch of nerve to the quadratus femoris and inferior gemellus (L5, S1) (L5, S1) Arterial Supply Medial circumflex femoral artery, inferior gluteal artery, 1st - 4th perforating arteries, obturator artery, and some superior muscular branches of popliteal artery Relevant Approaches Posterior (Southern) approach to hipPosterior (Kocher-Langenbach) approach to acetabulum