Coccygeus

Description

Pelvic floor anatomy showing the components of levator ani muscle

Schematic drawing of the female pelvis from a hemipelvectomy view, i.e., midline view. The external surface of the coccygeus muscle is the sacrospinous ligament (SSL). Note the ischial spine (IS) and the relationship between this bony protuberance and the sacrospinous ligament to nearby branches of the sacral plexus is shown in yellow. Note that a transvaginal procedure that would suture into the coccygeus muscle from internally, would be very near many of the branches and sources of the sacral plexus. Related structures include the obturator nerve (ON), lumbosacral trunk (LST), sciatic nerve (SN), pudendal nerve (white arrow), sympathetic trunk (black arrow), the L5 vertebra (L5), and upper four sacral ventral rami (S1–S4). Piriformis (P) is seen covering the anterior surface of the sacrum. A small nerve branch to the levator ani and coccygeus muscles is seen on their internal surface

Name

• Coccygeus
• Ischiococcygeus

General

• Sheet of muscle and fibrous tissue at the floor of the pelvis
• Together with Levator Ani, forms the Pelvic Diaphragm

Gross Anatomy

• Origin: Ischial Spine
• Insertion: Inferior end of sacrum, coccyx
• Aponeurotic portion of muscle forms the sacrospinous ligament

Function

• Support the pelvic viscera
• Flexion of coccyx
• Weakly supports opening/closing of levator hiatus, preserving ureteral and bowel continence

Innervation

• Anterior rami of spinal nerves S4, S5

Vascular Supply

• Branches of Internal Iliac Artery
  • Inferior gluteal
  • Inferior vesical
  • Pudendal arteries

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Clinical Significance

• Pelvic Floor Instability

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See Also

• Pelvis Anatomy Main
• Pelvic Pain Main
• Physical Exam Pelvis

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