Function: The ligaments and muscles of the perineum aid in actively supporting the abdominal and pelvic viscera, and play active roles in sexual functioning, micturation, defecation, and in childbirth. Relaxation of the perineum, in conjunction with the levator ani m., permits evacuation of the bladder and rectal contents.  Performing the Valsalva maneuver forcibly opens the apertures of the pelvic diaphragm.