Muscle · Pelvis

Levator ani

Musculus levator ani

Not one muscle but a broad muscular hammock — pubococcygeus, puborectalis and iliococcygeus — slung across the outlet of the pelvis from the pubis in front to the coccyx behind, with the tendinous arch of the obturator fascia as its side rails. It closes the bottom of the abdominal cavity, supports the pelvic organs, and forms a sling behind the rectum that maintains the anorectal angle. It is also the floor of the pressure system: the diaphragm above, transversus abdominis around, and levator ani below act together, so it lifts and holds every time you brace, cough or lift. The founder's chart puts the pelvic floor in the INHIBITED column, and its action map gives it two words that summarise the whole thing — pelvic stability and pressure control — which is why it belongs to the core-instability conversation and not only to continence.