「The ala of sacrum (plural alae) is a large triangular surface on either side of the body of the base of the sacrum. The alae support the psoas major muscles and the lumbosacral trunk which connects the lumbar plexus with the sacral plexus. In the articulated pelvis the alae are continuous with the iliac fossa.
It is slightly concave from side to side, and convex from the back and gives attachment to a few of the fibers of the iliacus.
The posterior quarter of the ala represents the transverse process, and its anterior three-quarters the costal process of the first sacral segment.
It serves as part of the border of the pelvic brim. The alae also form the base of the lumbosacral triangle. Structures attached to the ala:
」の索引にはその名称は見当たらない。また、ネットで日本語で検索をかけてみたが結果はゼロであった。