Determinants of Injuries in Young Dancers

Abstract
The epidemiology of dance injuries requires further study, in order to properly implement effective health interventions. This study aimed to pilot injury surveillance tools to assess the incidence of injuries in adolescent pre-professional dancers and identify the intrinsic and extrinsic risk factors associated with dance injuries. The study involved a prospective, cohort design. A population of adolescent dancers at a liberal arts high school dance program in Natick, Massachusetts, was studied over the nine-month school year in 2000/2001. Intrinsic risk factors, including anatomical characteristics, past medical history, menstrual history, and dance experience, were assessed with a pre-participation history and orthopedic physical exam. The extrinsic risk factors, including training, fatigue, stress, shoes, and calcium intake, were assessed with surveys completed every two weeks by the dancers. Study outcomes were: 1) self-reported injuries (SRIs), 2) reported injuries (RIs) assessed by a physical therapist in the school clinic, 3) duration of injuries, and 4) severity of injuries. Descriptive statistics and univariate analyses were performed on each risk factor. Thirty-nine of 55 dancers participated in the study. The average age was 15.3 years, and 85% of the dancers were female. The return rate for the biweekly surveys was 90%. Over one school year, there were 112 self-reported injuries, averaging 2.8 SRIs per dancer, and 71 reported injuries assessed by the physical therapist, averaging 1.4 RIs per dancer. Consistent with other studies, the most common locations for injuries were ankles, lower leg/calf, and back, usually caused by overuse, muscle strains, and sprains. Although the female dancers reported dancing significantly more hours (3.3 hours per day) than the males (2.7 hours/day), the males had a higher injury rate of SRIs (8.4 injuries/1,000 exposure hours of dancing vs. 4.1 injuries/1,000 hours) as well as RIs (5.5 injuries/1,000 hours vs. 2.6 injuries/1,000 hours). Older age and male sex were risk factors associated with SRIs and RIs. Most risk factors were found not to be statistically associated with the number of SRIs or RIs. Self-reported injuries occur frequently in pre-professional student dancers, who seek medical care in more than half the cases. Health professionals involved with dancers should be familiar with posterior ankle and low back problems. The rates of injuries appear almost twice as high in male dancers than female dancers. The main limitations to this study were small sample size and misclassification, recall, and reporting biases. With the information and tools of this pilot study, a multi-center study can be carried out to better assess risk factors on a larger dance population. Further research should aim to standardize injury definitions and classifications.