The iliac crest is the upper curved edge of the ilium, which is the largest bone in the pelvis. It serves as an important landmark for medical professionals and is easily felt on the sides of the lower back. The iliac crest provides attachment points for various muscles and ligaments, playing a crucial role in movement and stability. In addition to its anatomical significance, the iliac crest is often used as a site for bone grafts in surgical procedures. It is also a common reference point for measuring body fat and assessing overall health in fitness assessments.