Lesser sciatic foramen

An opening between the pelvis and the posterior thigh, the foramen is formed by the sacrotuberous ligament which runs between the sacrum and the ischial tuberosity and the sacrospinous ligament which runs between the sacrum and the ischial spine.

Boundaries
The lesser sciatic foramen has the following boundaries:
 * Anterior: the tuberosity of the ischium
 * Superior: the spine of the ischium and sacrospinous ligament
 * Posterior: the sacrotuberous ligament

Alternatively, the foramen can be defined by the boundaries of the lesser sciatic notch and the two ligaments.

Contents
It transmits the following structures:
 * the tendon of the Obturator internus
 * internal pudendal artery
 * internal pudendal veins
 * pudendal nerve