the right and left levator ani lie almost horizontally in the floor of the pelvis, separated by a narrow gap that transmits the urethra, vagina, and anal canal. the levator ani is usually considered in three parts: pubococcygeus, puborectalis, and iliococcygeus. the pubococcygeus, the main part of the levator, runs backward from the body of the pubis toward the coccyx and may be damaged during birth. some fibers are inserted into the prostate, urethra, and vagina. the right and left puborectalis unite behind the anorectal junction to form a muscular sling. some regard them as a part of the external anal sphincter. the iliococcygeus, the most posterior part of the levator ani, is often poorly developed.