The tensor fasciae latae is a muscle located on the upper and outer thigh. It arises from the iliac crest of the pelvis and inserts into the iliotibial band (IT band), which runs down the lateral side of the thigh. The primary function of the tensor fasciae latae is to assist in stabilizing the pelvis and thigh during movement, particularly during activities such as walking, running, and climbing stairs. It also plays a role in abduction, or moving the thigh away from the midline of the body.