Prospective Analysis of Body Composition and SF36 Profiles in Professional Dancers over a 7-Month Season: Is There a Correlation to Injury?

Abstract

This IRB-approved, prospective study evaluated body composition, strength, diet, lifestyle factors, and the incidence of injuries in professional dancers. Measurements were obtained from 15 dancers (6 males, 9 females) before a 7-month dance season and 13 dancers (5 males, 8 females) at the end of the season. Body composition was analyzed using dual x-ray absorptiometry. Quality-of-life variables were measured using the SF36 general health status survey. Post-season bone mineral density (BMD) for arms, trunk, ribs, pelvis, and total body for females was statistically significantly greater than preseason values. Total tissue mass for arms decreased significantly. No other body composition changes for females or males were observed, though striking differences were found when comparing dancers to age-matched and weight-matched non-dancers. Total body percent fat for female dancers was 43% lower than non-dancers, while lean mass was greater. Arm and spine BMD was lower than non-dancers but BMD for legs was significantly higher. For male dancers, there was significantly lower total body fat, greater lean mass in legs, and greater total body BMD than non-dancers. Grip strength did not change (preseason to post-season). Dietary profiles varied greatly, although most dancers met estimated minimum caloric requirements. Eleven dancers (85%) suffered injuries during the course of the season. There were no significant correlations between injury rate and body composition or lifestyle variables. All dancers scored significantly lower than population norms for the perception of pain. In summary, dancers maintained their body composition profiles despite the physical and emotional rigors of the dance season, and BMD actually increased significantly in females. The bodily pain score on the SF36 documents the impact of chronic injuries.