Incidence of Musculoskeletal Injury in US Army Unit Types: A Prospective Cohort Study

BACKGROUND: Musculoskeletal injuries during military service are a primary source of disability, resulting in 2.4 million annual health care visits and 25 million limited-duty days. While the injury incidence during basic training is well documented, there is little understanding of injury distribution by organization type in the US Army following initial training. OBJECTIVE: To compare injury incidence, distribution, and impact across various military units. METHODS: In this prospective observational cohort study, comprehensive injury data from subject questionnaires and medical chart reviews were collected over 12 months for 1430 initially healthy Army personnel, representing combat, combat support, combat service support, and ranger units. Health care utilization and time loss due to injury were also collected. RESULTS: Of 1430 soldiers, 481(33.6%) had time-loss injury, 222 (15.5%) were injured without limited work. 60 (4.2%) reported an injury but did not seek medical care, and 667 (46.6%) were uninjured. Across the whole sample, injuries were responsible for 5.9 +/- 14.4 medical visits per soldier, 21902 days of limited work, and $1337000 ($1901 +/- $6535 per soldier) in medical costs. Considering only those reporting injury, each person averaged 36.3 +/- 59.7 limited-work days. The injury incidence was highest in combat service support units (65.6%), with a risk ratio 1.60 times that of the reference group (combat 41.1%). CONCLUSION: Combat support and combat service support personnel were more likely to have 1or more injuries compared to rangers and combat personnel. The higher relative risk of injury in support units should be explored further.