Tensor Fascia Lata (TFL) – Functional Anatomy

Brief Overview

The Tensor fascia lata is a small fusiform muscle that, with some variance, tapers at the ends.

Origin – the anterior lip of the crest of the ilium

Insertion – lateral, condyle of the tibia via the IT band

Function – stabilizes the hip and knee, weak hip flexor and medial rotator

Detailed Origin / Insertion

The TFL is surrounded by two major fascial sections of the iliotibial tract. It attaches with the IT band along the iliac crest. As the muscle descends along the thigh, it tapers. The superior surface is anchored to a thick superficial section of the IT band. The deep surface is also veneered by a thick section of the IT band. The muscle tapers as the two sections of the IT band come together and eventually fuse into a thick band along the lateral thigh. This band eventually attaches to the lateral tibial condyle.

Detailed Function

The TFL tenses the fascia lata. This stabilizes the hip joint by keeping the head of the femur in the acetabulum. It is instrumental in pelvic stability while standing.

It is generally agreed to be a medial rotator and important in stabilizing the thigh during external rotation.

Although it is considered to be a weak abductor, it is active in walking. Like the gluteus medius, it pulls the front corner of the hip down on the weight-bearing leg. This stabilizes the other hip so that the leg does not drag as it swings forward.

It is active as a phasic muscle while standing. It is very active in sports, like cycling and skiing. It is a key component in the treatment of IT band syndrome or Runner’s knee.

The iliotibial tract (IT band) invests the tensor fascia lata and tenses the fascia to stabilize the knee. This post discusses the structure of the IT band in more detail.

Cranio Cradle Cup

This mug has classic, colorful illustrations of the craniosacral system and vault hold #3. It makes a great gift and conversation piece.