The tensor fasciae latae is a tiny muscle, inferior to the iliotibial band. This band, also called the IT band, is an elongated strip of fascia — a type of connective tissue — located in the thigh and knee.

The muscle originates in the ilium (the largest bone in the pelvis) and the front portion of iliac crest (the top, outer part of the ilium). It goes into the lateral condyle of the tibia (the outer side of the top of the tibia, or shinbone) through the iliotibial band.

This muscle is innervated by the superior gluteal nerve and performs the functions of hip flexion and abduction. These actions help to maintain one foot ahead of the other, as occurs in walking. It also provides lateral (side-to-side) stability to the knee. The muscle performs the role of a supplement ligament, and works with the minimus, medius, and upper maximum fibers.

The tensor fasciae latae also helps to stabilize the pelvis on the top of the femur (thigh) bone when a person is standing up straight. This muscle is used considerably during physical activities such as skiing or horseback riding. An imbalance of the pelvic area may occur if this muscle is shortened or strained.

The arterial supply to this muscle is through a branch arising from the profunda femoris, which is known as the lateral circumflex femoral artery.