Burden and risk factors for plantar fasciopathy in the military population from 2006 to 2015: a retrospective cohort study.

Introduction: Ankle and foot injuries are highly prevalent in the US Armed Forces, incurring medical and personnel costs for the Department of Defense. The purpose of this study was to evaluate the burden and risk factors of plantar fasciopathy (PF) in the US Military.

Methods: The Defense Medical Epidemiology Database identified all diagnosed PF cases in military service members from 2006 to 2015. A custom spreadsheet calculated incidence of PF and relative risk between sexes, military occupations and ranks. Relative risk of injury per demographic category (sex, age, service branch, rank and year) was also calculated.

Results: The overall incidence of PF from 2006 to 2015 was 12.85 per 1000 person-years, affecting 176 601 service members. 37 939 officers incurred PF at a rate of 17.65 per 1000 person-years (male 18.20 per 1000 person-years; female 14.80 per 1000 person-years). There were 116 122 enlisted personnel with PF that occurred at a rate of 12.22 per 1000 person-years (male 12.07 per 1000 person-years; female 13.22 per 1000 person-years). When compared with ground and naval gunfire officers, all officer specialties except for aviation and logistics had significantly higher risk of PF; aviation (relative risk (RR): 0.83, p<0.001) and logistics (RR: 0.94, p<0.001) had significantly lower risk. Regarding enlisted specialties, when compared with infantry, all occupations had significantly increased risk for PF except for Special Operations Forces (RR: 0.94, p=0.13). There were multiple associated factors identified with PF, including female sex, age >30, junior enlisted rank, a variety of military occupations and service in the Army.

Conclusions: PF was common in the US military during the study period, with multiple salient risk factors identified. These findings highlight the need for prophylactic interventions for populations with the greatest risk.