The levator ani is the primary pelvic floor muscle, forming a hammock beneath the pelvic organs. Its three parts (pubococcygeus, iliococcygeus, and puborectalis) are distinct but interconnected. Puborectalis is the primary continence muscle.
| Origin | Body of the pubis, tendinous arch of levator ani (white line of the obturator internus fascia), ischial spine |
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| Insertion | Perineal body, coccyx, anococcygeal ligament, and walls of the vagina, prostate, and rectum |
| Nerve Supply | Nerve to levator ani (S3, S4) and perineal branches of the pudendal nerve |
| Blood Supply | Inferior gluteal and internal pudendal arteries |
| Actions | Supports the pelvic viscera — the primary pelvic floor support; Lifts and constricts the rectum and vagina during straining; Co-contracts with abdominal muscles to manage intra-abdominal pressure |
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Levator ani avulsion from its pubic insertion during vaginal delivery is the most important pelvic floor injury causing pelvic organ prolapse. MRI detects avulsion as asymmetric insertion deficiency. Levator ani repair (levatorplasty) is performed in posterior compartment prolapse surgery. Pelvic floor physiotherapy targets levator ani for both urinary and fecal incontinence.
Assessed by digital vaginal or rectal examination — voluntary contraction produces elevation of the pelvic floor against the examining finger.
Pubic insertion avulsion of the levator ani during vaginal delivery producing pelvic floor deficiency and subsequent pelvic organ prolapse, detected by MRI and managed by prolapse repair surgery.
