Greater sciatic notch muscles. Of these, the superior gluteal vessels and nerve pass out above the piriformis, and the other structures below it. The greater sciatic notch is wider in women (about 74.4 degree in female) than in men (about 50.4 degree in male). Greater sciatic notch The greater sciatic notch is a notch in the ilium, one of the bones that make up the human pelvis. It lies between the posterior inferior iliac spine (above), and the ischial spine (below). The sacrospinous ligament changes this notch into an opening, the greater sciatic foramen. The notch holds the piriformis, the superior gluteal vein
Ischium muscle. Above the spine is a large notch, the greater sciatic notch; Below the spine is a smaller notch, the lesser sciatic notch. The superior ramus of the ischium (descending ramus) projects downward and backward from the body and presents for examination three surfaces: external, internal, and posterior. The external surface is quadrilateral in shape. It is bounded above by a groove that lodges the tendon of the external obturator; below, it is continuous with the inferior ramus; in front it is limited by the posterior margin of the obturator foramen; behind, a prominent margin separates it from the posterior