Sex and occupation are salient factors associated with lateral ankle sprain risk in military tactical athletes

Abstract

ObjectivesTo assess the risk of lateral ankle sprain (LAS) in male and female tactical athletes across different military occupations in the US military. DesignRetrospective cohort. MethodsThe Defense Medical Epidemiology Database was queried for the number of individuals with ICD-9 diagnosis codes 845.00 (sprain of ankle, unspecified) and 845.02 (calcaneofibular ligament sprain) on their initial encounter from 2006 to 2015. Relative risk (RR) and chi-square statistics were calculated assessing sex and occupational category on LAS risk. Results272,970 enlisted males (27.9 per 1000 person-years), 56,732 enlisted females (34.5 per 1000 person-years), 24,534 male officers (12.6 per 1000 person-years), and 6020 female officers (16.4 per 1000 person-years) incurred a LAS. Enlisted females in all occupational groups were at significantly higher risk for LAS than their male counterparts (RR 1.09–1.68; p<0.001), except for Engineers (p=0.15). Female officers had consistently higher risk for LAS in all occupational groups (RR 1.10–1.42; p<0.001) compared with male officers, except Ground/Naval Gunfire (p=0.23). Contrasted with Infantry, enlisted tactical athletes in the Special Operations Forces, Mechanized/Armor, Aviation, Maintenance, and Maritime/Naval Specialties were at lower risk (RR 0.38−0.93; p<0.001), Artillery, Engineers, and Logistics Specialties were at higher risk (RR 1.04–1.18; p<0.001), and Administration, Intelligence, and Communications were no different (p=0.69). Compared with Ground/Naval Gunfire officers, Aviation officers were at significantly lower risk (RR, 0.75; p<0.001), and Engineers, Maintenance, Administration, Operations/Intelligence, and Logistics officers were at higher risk (RR, 1.08–1.20; p<0.001). ConclusionsSex and military occupation were salient factors associated with LAS risk.