The iliotibial tract or iliotibial band is a large thick band of deep fascia (fascia lata) that runs down the lateral surface of the thigh. It acts to stabilize the hip and knee, and originates from the gluteus maximus and tensor fascia lata. The fascia lata is known as a subcutaneous stocking.
In this article we will discuss the gross and functional anatomy of the iliotibial tract, together with the clinical relevance of the structure
Origin & Insertion
The iliotibial tract is a band of thick connective tissue that runs along the lateral aspect of the thigh. It is a continuation of the tensor fascia lata, which arises from the outer lip of the iliac crest, the anterior superior iliac spine and the deep surface of the fascia lata and inserts between the two layers of the iliotibial tract (one third of the way down the thigh).
The gluteus maximus muscle also inserts into the iliotibial tract and is innervated by the inferior gluteal nerve (L5-S2). The superior part of the tract is splitted into two layers to enclose tensor fascia lata and tendon of the gluteus maximus muscle. The iliotibial tract continues to descend on the lateral surface of the thigh, and inserts onto the lateral tibial plateau at a projection known as Gerdy’s tubercle. It lies on top of the vastus lateralis head of the quadriceps femoris. The tensor fascia lata acts through the iliotibial band, and supports the knee. It extend the knee (maintains the knee in hyperextended condition) and laterally rotate the leg. It also acts as a hip flexor and medial rotator.
InnervationThe innervation of the tensor fascia lata is from the superior gluteal nerve (ventral rami of L4-S1), a branch of the sacral plexus. The nerve leaves the pelvis via the greater sciatic foramen, above the pear shaped piriformis muscle (a short external rotator of the hip). The superior gluteal nerve also innervates the gluteus medius and minimus (hip abductors and lateral rotators). As the tensor fascia lata crosses the hip and knee joint, it is able to act in association with the iliotibial tract to maintain pelvic position while a person is running jumping walking or standing.
Iliotibial Band Syndrome
Also known as iliotibial band friction syndrome, this is a common cause of knee pain arising from chronic inflammation due to intense physical activity, such as long distance running. The typical patient is young and physically active, usually a long distance runner or cyclist.
Continued activity can result in the inflamed bursa near the lateral femoral epicondyle and pain is due to repetitive friction of the band against the epicondyle during knee movement.