Hip Range of Motion and Strength in Young Pre-Professionals Ballet Dancers Versus Non-Dancers

Introduction: Lower-extremity external rotation, commonly known as turnout, is a fundamental skill in dance. Limited data exist regarding joint range of motion and strength in pre-professional young dancers and non-dancers. This study aimed to evaluate the differences in hip range of motion and hip strength between pre-professional ballet dancers and non-dancers. Additionally, the study assessed the variations between the left and right sides within each group. Methods: This observational study assessed 60 pre-professional ballet dancers and 31 non-dancers with an average age of 11.91 ± 1.49. Evaluation included passive hip rotation, tibial torsion, total passive turnout measured with digital goniometers, and total active turnout (both static and dynamic) through standing on paper and rotational discs. Hip rotation strength was measured using a force sensor device. Statistical analyses encompassed student t-tests, Pearson's correlations, and ANCOVA with age and body weight as covariates, applying the Bonferroni correction for multiple comparisons. Results: Ballet dancers exhibited greater passive hip external rotation and lower passive hip internal rotation compared to non-dancers. They also demonstrated superior total active turnout (static and dynamic). After adjusting for age and weight, dancers demonstrated significantly higher hip external rotation strength than non-dancers. Hip internal rotation strength did not differ significantly between the groups. Ballet dancers displayed inherent asymmetry, with the left side showing greater tibial torsion and standing active turnout, while the right side exhibited greater hip external rotation during dynamic active turnout. Non-dancers did not show significant side differences. Conclusions: Young pre-professional ballet dancers exhibited significant hip rotation differences compared to non-dancers, including notable right-left asymmetry. These findings should be considered when planning training, aiming to optimize musculoskeletal attributes and promote balanced hip rotation. Recognizing these asymmetries and addressing muscular imbalances is vital for injury prevention and performance enhancement.