Compensatory tibial torsion as a component of ballet turnout

Purpose: Classical ballet emphasizes external rotation (ER) of the hip joint as the primary mechanism of turnout, with ideal turnout being 180 degrees. Due to anatomical constraints, few dancers are able to achieve this ideal without compensating elsewhere in the kinetic chain. It is common for dancers to compensate for inadequate hip ER with tibial torsion. Misalignment caused by compensations puts dancers at risk for ligamentous injuries, degenerative bony changes, and reduced strength. The purpose of this study is to determine the contribution of tibial torsion to turnout in a sample of elite ballet dancers. Methods: The study sample consisted of five male and five female professional ballet dancers. Using motion capture technology, each dancer was filmed completing barre exercises at three different times during the performance season. Rotational movement at the femoroacetabular and tibiofemoral joints was approximated using motion markers placed on common anatomical landmarks. Results: Degrees of ER at the femoroacetabular and tibiofemoral joints remained consistent between visits and trials. Females demonstrated tibial turnout of 12-14 degrees across various movements, and males demonstrated 15-17 degrees. Across all movements, females demonstrated more turnout at the hip joint than males. Femoral and tibial ER also varied by the type of movement performed. Conclusions: According to classical ballet ideal aesthetics, 5 degrees of turnout should originate from each knee joint. The degrees of turnout originating from the knee in this sample exceed these values. The degrees of turnout observed may be due to dancers' anatomy and extent of training.