Sacrum apex is directed downward and presents an oval facet for articulation with the coccyx. The sacral canal as a continuation of the vertebral canal runs throughout the greater part of the sacrum. The sacral angle is the angle formed by the true conjugate with the two pieces of sacrum. Normally it is greater than 60 degrees. A sacral angle of lesser degree suggests funneling of the pelvis. The sacral promontory marks part of the border of the pelvic inlet, and comprises the iliopectineal line and the linea terminalis. The sacral promontory articulates with the last lumbar vertebra to form the
Sacrum the direction of rotation of the superior portion of the sacrum opposite the side of the superior axis pole, and the last letter pertains to the pole. English "sacrum" was introduced as a technical term in anatomy in the mid-18th century, as a shortening of the Late Latin name "os sacrum" "sacred bone", itself a translation of Greek ἱερόν ὀστέον, the term found in the writings of Galen. Prior to the adoption of "sacrum", the bone was also called "holy bone" in English, paralleling German "heiliges Bein" or "Heiligenbein" (alongside "Kreuzbein") and Dutch "heiligbeen". The origin of Galen's term is