Adolescent maturation and injury risk in an elite ballet school: a 7-year cohort study of 506 students.

Abstract

This study investigates how growth and maturation-related factors are associated with growth and bone injury risk in elite-level ballet students. 506 full-time dance students (preprofessional) were included in the study across a 7-year time period. A causal framework was outlined using a directed acyclic graph (DAG) to outline the investigatory approach. This was then used to inform a model-building process, which used a combination of generalised linear and polynomial mixed-effects models to identify relationships between growth-related and bone-related injury occurrence and percentage of adult height, growth rate, body mass index (BMI) percentile and change BMI, while controlling for year group. A significant positive relationship (p=0.0006) was observed between growth rate and growth injury occurrence, while a significant (quadratic p value=0.0019) inverted U-shaped relationship was observed between percentage of adult height and growth injury occurrence. Growth rate and percentage of adult height demonstrated similar associations with bone injury; however, substantially greater error was observed when analysing bone injury compared with growth-related injury. No relationships were observed between age-specific and sex-specific BMI percentile or change in BMI and either injury type. Both growth rate and maturation stage (85%-95% of adult height) were associated with the risk of growth-related injury in dancers. The combination of these factors can be used to implement proactive injury-reduction strategies targeting growth-related injuries.