GLOSSARY

The iliotibial band (IT band) is a thick, strong band of fibrous connective tissue on the lateral thigh; it is actually a thickening of the fascia lata running from the pelvis to below the knee, and it is not a muscle.

Attachments

• Above: the iliac crest, receiving fibres from the TFL and about three-quarters of the gluteus maximus.
• Below: Gerdy’s tubercle on the lateral tibia, with attachments to the patella and femur.

Functions

• Lateral hip and knee stability in single-leg stance.
• Storing and releasing elastic energy in running; research suggests the IT band acts like a spring.
• Force transfer from the thigh muscles to the leg.

Correcting Common Beliefs

• Stretching the IT band: this band is very stiff, and its length does not change meaningfully with stretching or foam rolling; perceived improvement is mostly due to neural effects and effects on the attached muscles (TFL and gluteals).
• “Friction” over the epicondyle: the old theory that the IT band rubs back and forth over the lateral epicondyle has been questioned; a newer view proposes compression of a richly innervated fat pad beneath the band.

Relevance to Sport

Iliotibial band syndrome (ITBS): the most common cause of lateral knee pain in runners and cyclists; pain typically worsens at about 30 degrees of knee flexion and when running downhill. Treatment: load management, strengthening the hip abductors, adjusting running volume and technique, and bike fit.