levator ani

:  a broad thin muscle that is attached in a sheet to each side of the inner surface of the pelvis and descends to form the floor of the pelvic cavity where it supports the viscera and surrounds structures which pass through it and inserts into the sides of the apex of the coccyx, the margins of the anus, the side of the rectum, and the central tendinous point of the perineum—see iliococcygeus, pubococcygeus