Pudendal Canal

canalis pudendalis

The pudendal canal, or Alcock canal, is a tunnel formed by a split in the obturator fascia on the lateral wall of the ischioanal fossa. It runs forward from the lesser sciatic foramen toward the back of the perineal membrane and carries the pudendal nerve and internal pudendal vessels.

Anatomical Data

Boundaries & Contents

Location	Lateral wall of the ischioanal fossa, about 4 cm above the ischial tuberosity.
Boundaries	Obturator internus fascia laterally (split layers form the canal) Ischioanal fossa fat medially Lesser sciatic foramen posteriorly Posterior edge of the perineal membrane anteriorly
Contents	Pudendal nerve Internal pudendal artery Internal pudendal vein Nerve to obturator internus (at its entrance)

Biomechanics

Function & Actions

Protects and guides the pudendal neurovascular bundle from the gluteal region into the perineum.

Clinical Relevance

Clinical Notes

The pudendal nerve can be compressed in the canal, particularly in cyclists and after prolonged sitting or pelvic surgery, causing pudendal neuralgia. The pudendal nerve block, used in childbirth and perineal surgery, targets the nerve near the ischial spine as it enters the canal.

Pathology

Common Injuries & Conditions

Pudendal Nerve Entrapment

Compression of the pudendal nerve in the canal causing burning pain in the genitals, perineum or anus that worsens with sitting and eases on standing.

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