Vertebro-pelvic ligaments are bands connecting the vertebrae with the pelvis and stabilizing mainly the lumbosacral joint.

The main ligaments supporting and holding the bony pelvis together are:

• ischiosacral ligaments:
  • sacrospinous ligament
  • sacrotuberous ligament;
• iliolumbar ligament.

Ischiosacral ligaments:

Two very important ligaments that help keep the sacrum in the correct position at rest and during exercises are attached to the ischium. 

Both ligaments prevent the rotation of the ilium. 

Ligaments also provide the stability of the sacroiliac joint, and they include:

• sacrospinous ligament,
• sacrotuberous ligament.

Both ligaments create two foramina:

• Greater sciatic foramen - located above the sacrospinous ligament, between the iliac bone, sacrotuberous and sacrospinous ligaments, ischial spine, and the greater sciatic notch of the ischium; it contains piriformis muscle, as well as blood vessels and nerves such as superior gluteal artery, vein and nerve, sciatic and posterior femoral cutaneous nerve;
• Lesser sciatic foramen - located below the sacrospinous ligament, between sacrospinous ligament, ischial spine, and the lesser sciatic notch; through the foramen pass the internal pudendal artery and vein, as well as the obturator internus tendon and nerve to the mentioned muscle.