what runs between the sacrospinous and sacrotuberous ligaments
The lesser sciatic foramen is an opening (foramen) between the pelvis and the back of the 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.he lesser sciatic foramen has the following boundaries: 1  Anterior: the tuberosity of the ischium. 2  Superior: the spine of the ischium and sacrospinous ligament. 3  Posterior: the sacrotuberous ligament.