Hip and Knee Rotation: The Inverse Relationship Mediated by the Iliotibial Band

Hip and knee rotation are inversely coupled via the iliotibial band (ITB), a dense fascial band running from the iliac crest to the lateral tibia (Gerdy's tubercle).

Mechanism

• Hip Internal Rotation → ITB tightens/winds → pulls tibia into External Rotation.
• Hip External Rotation → ITB slackens/unwinds → allows tibia to rotate Internally.

Clinical Relevance

This coupling influences gait, squat mechanics, and patellofemoral tracking. Excessive hip internal rotation (e.g., from gluteal weakness) drives knee valgus and tibial external rotation, increasing ACL injury risk and patellofemoral pain. Assessment and correction of hip rotation control are central to lower-extremity rehabilitation.