Fascia · Thigh

Iliotibial band

Tractus iliotibialis

A thick longitudinal cord down the outside of the thigh — a reinforced strip of the fascia that sleeves the whole thigh. Tensor fasciae latae and part of gluteus maximus insert into its top, so it acts as their long tendon, and it anchors below onto the outer shin just past the knee. Its real job is lateral stability: every time you stand on one leg it helps stop the pelvis dropping and the knee falling inward. It is very stiff and cannot meaningfully be stretched, so outer-knee or outer-hip pain attributed to it is usually better understood as a load and hip-control problem than as a tight band that needs lengthening.