Levator ani

The levator ani, also known as the muscular pelvic diaphragm, is the musculotendinous sheet that forms the majority of the pelvic floor, supports the pelvic viscera, and aids in the urinary and faecal evacuation as well as maintaining continence.

The levator ani has three main components, each of which is paired 1,2,5:

  • pubococcygeal (pubovisceral) muscle
    • subparts: puboperineal, pubovaginal, puboanal
  • iliococcygeus muscle
  • puborectalis muscle

The pubococcygeus runs from the inner surface of the pubis and obturator fascia with fibres fusing medially at the perineal body and musculature of the prostate/vagina

The ischiococcygeus is a triangular muscle with its base attaching to the lateral aspect of the inferior sacrum and coccyx and apex attached to the ischial spine. It forms the posterosuperior part of the levator ani. It flexes the coccyx anteriorly and partially fuses with the sacrospinous ligament. The iliococcygeus attaches the inner tip of the coccyx posteriorly. Posterolaterally, it attaches to the ischial spine and along the tendinous arch of the obturator fascia (a.k.a. the tendinous arch of the levator ani), which is a thickened band of the fascia covering the inner aspect of the obturator internus muscle. Anteriorly and medially, it fuses with the pubococcygeus.

Coccygeus (Ischiococcygeus) is not formally part of levator ani 3

  • pelvic surface: branches of S3, S4
  • perineal surface: branches of the pudendal nerve
  • thinning or aplasia of one or both sides is common (~50%) 4
Abdominal and pelvic anatomy
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Article Information

rID: 32706
Section: Anatomy
Synonyms or Alternate Spellings:
  • Pelvic floor
  • Muscular pelvic diaphragm
  • Levator ani muscle complex

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Cases and Figures

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    Normal MRI pelvis (fistula protocol)
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