Pubococcygeus muscle (PC muscle)A muscular sling, shaped like a figure eight, stretching from the pubicbone in front to the tailbone in back (one loop around the vagina orpenis and one loop around the anus); known as the PC muscle, itcontrols urine flow and contracts during orgasm. A well-toned PC musclecan enhance sex and orgasm. You can exercise your PC muscle by doing Kegel exercises, which can include the use of a vaginal barbell.