Quick Facts
Origin: Ischial spine and tendinous arch of levator ani.
Insertion: Coccyx, iliococcygeal raphe, and anococcygeal ligament.
Action: Provides structural support to adjacent pelvic structures; fecal continence.
Innervation: Nerve to levator ani muscle (S3-S4).
Arterial Supply: Inferior gluteal, inferior vesical, and internal pudendal arteries.
Related parts of the anatomy
Origin
The iliococcygeus muscle originates from the:
- pelvic aspect of the ischial spine;
- posterior portion of the tendinous arch of levator ani.
Insertion
The fibers of the iliococcygeus muscle travel posteromedially, where:
- its superior fibers insert onto the anterolateral aspect of the coccyx;
- its inferior fibers insert onto the iliococcygeal raphe, which is the midline intersection between the inferior fibers of the left and right iliococcygeus muscles. This raphe blends with the anococcygeal ligament.
Key Features & Anatomical Relations
The iliococcygeus muscle is one of the three muscles that form the levator ani muscle, which itself forms a large part of the pelvic diaphragm. The iliococcygeus is a broad, flat skeletal muscle. It is located:
- medial to the ischium and ischioanal fossa;
- lateral to the urinary bladder, the rectum, and the pubococcygeus and puboanalis muscles.
Actions
As part of the pelvic diaphragm, the iliococcygeus muscle provides structural support to adjacent pelvic structures and elevates the pelvic floor. Its fibers are capable of maintaining a tonic contraction at rest, which relaxes during defecation (Standring, 2016).
List of Clinical Correlates
- Prolapse of pelvic viscera
- Urinary incontinence
- Fecal incontinence
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
Actions
As part of the pelvic diaphragm, the iliococcygeus muscle provides structural support to adjacent pelvic structures and elevates the pelvic floor. Its fibers are capable of maintaining a tonic contraction at rest, which relaxes during defecation (Standring, 2016).
Learn more about this topic from other Elsevier products
Iliococcygeus Muscle
The iliococcygeus muscles arise from the lateral pubic symphysis, travel over the pelvic sidewall (i.e., obturator internus muscle) attached to the arcus tendineus levator ani laterally, and meet in the midline at the anococcygeal raphe and the coccyx to form the levator plate‐1).
