The iliac crest is the upper edge of the wing of the ilium, the anterior projection is called the anterior superior iliac crest and the posterior projection is called the posterior superior iliac crest. The bony structure that protrudes from the left and right sides of the lower edge of the human abdomen is the anterior superior iliac crest of the human body, and moving posteriorly along the crest of the bone, the posterior superior iliac crest can be touched, which participates in the formation of the posterior part of the human pelvis. On either side of the lower lumbar border, the highest point of the right and left iliac crests are connected at the level of the 4th lumbar spinous process or between the 3rd and 4th lumbar vertebrae. The connection between the anterior superior iliac crest and the posterior superior iliac crest is the location of the human iliac crests, on either side of the human pelvis. The iliac spine is important as a physiologic landmark for a number of examinations and often assists the clinic in the diagnosis of some diseases or puncture marking points.