Coccygeus muscle
The Coccygeus or ischiococcygeus is a muscle of the pelvic floor, located posterior to levator ani and anterior to the sacrospinous ligament.
It is a triangular plane of muscular and tendinous fibers, arising by its apex from the spine of the ischium and sacrospinous ligament, and inserted by its base into the margin of the coccyx and into the side of the lowest piece of the sacrum.
In combination with the levator ani, it forms the pelvic diaphragm.
It assists the levator ani and piriformis in closing in the back part of the outlet of the pelvis.
