Innervation of the levator ani muscles: Description of the nerve branches to the pubococcygeus, iliococcygeus, and puborectalis muscles

Bogdan A. Grigorescu, George Lazarou, Todd R. Olson, Sherry A. Downie, Kenneth Powers, Wilma Markus Greston, Magdy S. Mikhail

Research output: Contribution to journalArticle

39 Scopus citations


We described the innervation of the levator ani muscles (LAM) in human female cadavers. Detailed pelvic dissections of the pubococcygeus (PCM), iliococcygeus (ICM), and puborectalis muscles (PRM) were performed on 17 formaldehyde-fixed cadavers. The pudendal nerve and the sacral nerves entering the pelvis were traced thoroughly, and nerve branches innervating the LAM were documented. Histological analysis of nerve branches entering the LAM confirmed myelinated nerve tissue. LAM were innervated by the pudendal nerve branches, perineal nerve, and inferior rectal nerve (IRN) in 15 (88.2%) and 6 (35.3%) cadavers, respectively, and by the direct sacral nerves S3 and/or S4 in 12 cadavers (70.6%). A variant IRN, independent of the pudendal nerve, was found to innervate the LAM in seven (41.2%) cadavers. The PCM and the PRM were both primarily innervated by the pudendal nerve branches in 13 cadavers (76.5%) each. The ICM was primarily innervated by the direct sacral nerves S3 and/or S4 in 11 cadavers (64.7%).

Original languageEnglish (US)
Pages (from-to)107-116
Number of pages10
JournalInternational Urogynecology Journal
Issue number1
StatePublished - Jan 2008



  • Iliococcygeus muscle
  • Inferior rectal nerve
  • Levator ani muscles
  • Pubococcygeus muscle
  • Puborectalis muscle
  • Pudendal nerve

ASJC Scopus subject areas

  • Obstetrics and Gynecology
  • Urology

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