This is a pointed, triangular projection of variable length on the posterior margin of the ischium. Attaching to the apex of this projection is the sacrospinous ligament, which is the tendinous posterior edge of the coccygeus muscle. Attaching to its external surface is the superior gemellus muscle and to its internal surface the levator ani and coccygeus muscles. Its superior margin contributes to the greater sciatic notch, while its inferior margin contributes to the lesser sciatic notch.

The word spine comes from the Latin spina meaning a thorn.

Columna vertebralis

Épine

Colonne vertébrale

Columna vertebral