sacrotuberous ligament

The sacrotuberous ligament runs from the sacrum to the ischial tuberosity. Along with the sacrospinous ligament (which runs to the ischial spine), the sacrotuberous ligament prevents the lower part of the sacrum tilting upwards and backwards under the weight of the rest of the vertebral column.

The sacrotuberous ligament forms part of the boundary of both the greater and lesser sciatic foramina. It forms an attachment for several muscles, most notably it is part of the origin of gluteus maximus.