Iliac Crest

The iliac crest is the curved superior border of the ilium, the largest and uppermost of the three bones that form each hip bone. It forms the prominent upper rim of the pelvis that can often be felt beneath the skin around the waist. The crest extends from the anterior superior iliac spine at the front to the posterior superior iliac spine at the back .¹

The iliac crest is a bony landmark rather than a separate bone or joint. It forms the superior edge of the broad, wing-shaped portion of the ilium called the iliac ala. The anterior and posterior superior iliac spines are therefore endpoints of the crest, not alternative names for the entire structure .¹

The iliac crest also provides attachment for muscles and connective tissues linking the pelvis with the trunk. For example, parts of the external oblique, internal oblique, and transversus abdominis muscles attach to the iliac crest. These muscles contribute to movement and stabilization of the trunk and abdominal wall .^1,2

Because the iliac crest is relatively superficial and palpable, it is also used as an anatomical reference point during physical examination and clinical procedures. A line connecting the highest points of the left and right iliac crests, known as the intercristal or Tuffier's line, can help clinicians estimate the level of the lumbar spine .¹