iliococcígeos

The iliococcygeus is a muscle of the pelvic floor and a component of the levator ani group. It forms the posterior part of the floor, helping to support pelvic organs and maintain continence. Its fibers extend from the tendinous arch of the levator ani along the inner pelvic wall to insert on the coccyx and the anococcygeal body or midline raphe.

Anatomy and relations: The muscle originates from the arcus tendineus levator ani, a thickening of fascia that runs from the pubic bone to the ischial spine. It lies posterior to the pubococcygeus and contributes to the lateral-to-medial sling of the pelvic floor, reinforcing the region between the pelvic sidewall and the coccyx.

Innervation: The iliococcygeus is mainly innervated by branches of the nerve to levator ani (typically S3–S4), with possible minor contributions from nearby nerves such as the inferior anal nerve.

Function: It supports pelvic viscera, helps elevate the pelvic floor, and contributes to maintaining the anorectal angle, thereby assisting continence. The muscle also plays a role in resisting increases in intraabdominal pressure during activities such as coughing, sneezing, defecation, and childbirth.

Clinical significance: Weakness, injury, or displacement of the pelvic floor muscles, including the iliococcygeus, can contribute to pelvic organ prolapse and urinary or fecal incontinence. Pelvic floor rehabilitation and, in some cases, surgical interventions may address dysfunction or postoperative restoration of support. There is natural variation in the size and exact attachments of the iliococcygeus among individuals.