Bony pelvis (inferior view) (Latin)

The apertura inferior pelvis is the inferior opening of the true pelvis. It is formed anteriorly by the arcus pubicus, rami ischiopubici and tubera ischiadica, and posteriorly by inferior borders of the ligg. sacrotuberales and apex ossis coccygis. Since the latter structures are both slightly yielding, this results in a less rigid posterior half of the apertura inferior pelvis.