What Is the Tensor Fasciae Latae?
The tensor fasciae latae (TFL) is a muscle of the upper outer thigh. It stretches vertically down the outside of the leg from the hip to the knee via the iliotibial (IT) band. Among other things responsible for the abduction of the hip, or the lifting of the leg to the side, it is significant for its role in stabilizing the knee relative to the hip. This muscle finds its origin on the outside of the iliac crest, the bony prominence on the ilium that can be felt on the top outer part of the hip, and along the anterior superior iliac spine, the ridge running downward from the crest. The tensor fasciae latae arises from between two muscles: the gluteus medius on the back outer part of the hip and the sartorius, which begins on the outside of the hip and crosses the front of the thigh. It then runs downward from the hip, angling slightly outward with its fibers running parallel, to insert along the IT band about a third of the way down the outer thigh.
