Associations of age, aerobic fitness, and body mass index with injury in an operational Army brigade. (November 2017) - Rappole, Catherine
Abstract: Objectives: To investigate the effects of age, aerobic fitness, and body mass index (BMI) on injury risk in operational Army soldiers. Design: Retrospective cohort study. Methods: Male soldiers from an operational Army brigade were administered electronic surveys regarding personal characteristics, physical fitness, and injuries occurring over the last 12 months. Injury risks were stratified by age, 2-mile run time, and BMI. Analyses included descriptive incidence, a Mantel–Haenszel χ 2 test to determine trends, a multivariable logistic regression to determine factors associated with injury, and a one-way analysis of variance (ANOVA). Results: Forty-seventy percent of 1099 respondents reported at least one injury. A linear trend showed that as age, 2-mile run time, and BMI increased, so did injury risk (p < 0.01). When controlling for BMI, the most significant independent injury risk factors were older age (odd ratio (OR) 30 years–35 years/≤24 years = 1.25, 95%CI: 1.08–2.32), (OR ≥ 36 years/≤24 years = 2.05, 95%CI: 1.36–3.10), and slow run times (OR ≥ 15.9 min/≤13.9 min = 1.91, 95%CI: 1.28–2.85). An ANOVA showed that both run times and BMI increased with age. Conclusions: The stratified analysis and the multivariable logistic regression suggested that older age and poor aerobic fitness are stronger predictors of injury than BMI.