Comparisons in physical characteristic of professional ballet and collegiate dancers

Dancers are a group of athletes with unique physical and performance characteristics. Dance medicine and science is a growing field, as researchers and clinicians see the need for information specific to this population due to high injury rates. Comprehensive information on separate types of dancers, especially collegiate dancers, is unavailable. The purpose of this study was to describe and compare characteristics of professional ballet and collegiate dancers, as well as investigate the relationships among these characteristics. The first portion of the study investigates differences in body composition, lower extremity and trunk muscular strength, dynamic postural stability, and landing kinematics of professional ballet dancers and collegiate dance majors. The second portion of the study determines the ability of strength to predict dynamic postural stability and kinematic variables that are potential risk factors for injury including, knee valgus, ankle inversion, and foot pronation. Fifty nine dancers participated in the study (30 professional ballet and 29 collegiate). Equal proportions of males and females were in each group. Dancers completed an injury history questionnaire, followed by assessments of body composition, dynamic postural stability, kinematics during a dance jump task, and isokinetic and isometric muscular strength. Results demonstrate that professional dancers are significantly stronger than collegiate dancers for most muscle groups tested. The study found no significant differences in dynamic postural stability, and minimal differences in kinematics. No differences were found in self-reported injury histories, except that a greater proportion of professional dancers reported injuries to the ankle, and foot and toe regions. Regression analyses revealed that gender and trunk rotation strength predicted dynamic postural stability. Gender and knee flexion strength predicted maximum knee valgus angle. Gender and knee extension strength predicted ankle inversion angle at initial contact and, gender and knee flexion strength predicted maximum inversion angle. No significant predictors of foot pronation angle were found. This study provides a comprehensive assessment of professional ballet and collegiate dancers and provides insight into the relationships among their characteristics and abilities. Further research should investigate relationships in each gender separately, as well as study additional variables that explain the relationship between strength and biomechanics.