Anatomy of the Pelvic Floor

The PELVIC FLOOR consists of muscles, bones, and viscera/organs. The pelvic muscles lie between the pubic bone in the front and the tailbone at the back forming a sling commonly referred to as the “Pelvic Floor”.

The pelvic diaphragm is composed of the coccygeus muscle posteriorly and the levator ani anterolaterally. Although they are not fully distinct, the components of the levator ani consist of the iliococcygeus, the pubococcygeus, and the puborectalis muscle group. 

The following diagram comes from Amy Stein, she has a great book with a lot more information about the pelvic floor and pain.

 The Pelvic Floor has 3 muscle layers:

Superficial perineal layer: innervated by the pudendal nerve
• Bulbocavernosus
• Ischiocavernosus
• Superficial transverse perineal
• External anal sphincter (EAS)

Deep urogenital diaphragm layer: Anatomy of the Pelvic Floorinnervated by pudendal nerve
• Compressor urethera
• Uretrovaginal sphincter
• Deep transverse perineal

Pelvic diaphragm: innervated by sacral nerve roots S3-S5
• Levator ani: pubococcygeus (pubovaginalis, puborectalis), iliococcygeus
• Coccygeus/ischiococcygeus
• Piriformis
• Obturator internus

Trigger Points 

Tenderness or spasms in these muscles can refer pain to other areas:

  1. Bulbocavernosus and Ischiocavernosus refer pain to the perineum and adjoining urogenital structures
  2. EAS refers to posterior pelvic floor
  3. Levator ani and coccygeus refer to sacrococcygeal area (near the low back and tailbone)
  4. Levator ani to vagina
  5. Obturator internus to vagina and anococcygeal area

Function of the Pelvic floor (PF) muscles include:

  • Support of the pelvic organs (bladder, uterus, prostate, rectum)
  • Urinary and fecal continence
  • Sexual performance (orgasm)
  • Stability of connecting joints (hips, sacroiliac, lumbar joints)
  • Venous and Lymphatic Pump for the pelvis

Adapted from Body Harmony Physical Therapy

More Diagrams and Information on the Pelvic Floor

Diane Lee PDF: Understanding Back and Pelvic Girdle Pain – with basic anatomy

Interactive Anatomy: The 3D Vulva

The Anatomy of the Female Pelvis for Dummies 

Muscles in Detail of the Pelvic Floor

The Piriformis Muscle and Pelvic Floor

The Ultimate Pelvic Floor Anatomy Resource by Pelvic Guru