A muscle formed by the puborectal muscle, the elevator muscle of the prostate, the pubococcygeal muscle, and the iliococcygeal muscle, with origin from the back of the pubis and the spine of the ischium, with insertion into the anococcygeal ligament and the sides of the lower part of the sacrum and coccyx, with nerve supply from the fourth sacral nerve, and whose action draws the anus upward in defecation and supports the pelvic viscera.