Iliotibial Band

tractus iliotibialis

The iliotibial band is a thick longitudinal reinforcement of the fascia lata running from the iliac crest to Gerdy tubercle on the lateral tibia, transmitting force from the tensor fasciae latae and posterior gluteus maximus to the lateral knee. It provides lateral knee stability during stance phase and transitions from a knee flexor (in flexion) to an extensor (in extension) at approximately 30 degrees of knee flexion, the impingement zone where IT band syndrome pain occurs.

Region: Thigh

Biomechanics

Function & Actions

Transmits TFL and gluteus maximus force to the lateral tibia; lateral knee stabilisation; hip abductor moment arm

Clinical Relevance

Clinical Notes

IT band syndrome is the most common cause of lateral knee pain in runners, producing pain specifically at the lateral femoral epicondyle at the 30-degree impingement zone that appears consistently at a predictable distance into a run. The Noble compression test reproduces pain with pressure over the lateral epicondyle at 30 degrees of knee flexion. Training load management, hip abductor strengthening, and addressing TFL tightness resolve most cases without surgery.

Pathology

Common Injuries & Conditions

IT Band Syndrome

Friction of the iliotibial band over the lateral femoral epicondyle during repetitive knee flexion-extension producing lateral knee pain at a consistent running distance, managed with load modification and hip strengthening.