The iliac spine refers to bony projections located on the ilium, which is the largest bone of the pelvis. There are two main types: the anterior superior iliac spine (ASIS) and the anterior inferior iliac spine (AIIS). These spines serve as important attachment points for muscles and ligaments, playing a crucial role in the movement and stability of the hip joint. The iliac spines are easily palpable on the surface of the body, making them significant landmarks in anatomy. They are often used in medical assessments and procedures, as well as in physical therapy to evaluate posture and alignment of the pelvis and lower limbs.