Alcock’s canal (pudendal canal)

Scientific basis

Alcock’s canal is classically described as a canal formed by a splitting of the obturator internus fascia. A recent cadaver study (Chikazawa et al., 2026) instead places the pudendal nerve within a fascia derived from the sacrotuberous ligament, without the nerve passing through the obturator internus fascia proper — an anatomical refinement that adds to the classical description rather than replacing it. The canal corresponds to a portion of the pudendal pathway located after the nerve passes through the region of the ischial spine and the sacrospinous and sacrotuberous ligaments. It is not a rigid bony tunnel, but a fascial environment integrated with muscular and connective structures. When sitting, this region is of particular functional interest because of its proximity to the pelvic and perineal structures exposed to support pressure.

Blue Portance / SBNFA™ reading

The SBNFA™ considers Alcock’s canal a mechanical environment of the pudendal nerve. The analysis looks in particular at the tissues’ capacity to deform, their relative mobility, gliding, local stress and the possibility of varying that stress.

Contribution to the analysis of sitting

The issue is therefore not limited to a static pressure measurement. It also involves the duration of exposure, the distribution of support and the ability of the pelvic system to change configuration regularly.

Not to be confused with

Pudendal nerve, which runs through the canal; pudendal neuralgia, the clinical picture; Alcock’s canal syndrome, an expression used in some contexts to refer to pudendal nerve involvement, best covered under the Pudendal neuralgia entry.

Sources and scope

• Robert et al. (2009): course of the pudendal nerve and Alcock’s canal
• Hough et al. (2003): pudendal nerve anatomy and CT-guided perineural injection
• Ziouziou et al. (2013): Alcock’s canal syndrome and pudendal neuralgia
• Chikazawa et al. (2026): two fascial layers of the pudendal canal