The incidence of plantar fasciitis in the United States military

Abstract

Background: Although plantar fasciitis is the most common cause of heel pain, little has been reported on the incidence rates of this disorder. We sought to determine the incidence rate and demographic risk factors of plantar fasciitis in an ethnically diverse and physically active population of United States military service members.

Methods: A query was performed with use of the Defense Medical Epidemiology Database for the International Classification of Diseases, Ninth Revision, Clinical Modification, code for plantar fasciitis (728.71). Multivariate Poisson regression analysis was used to estimate the rate of plantar fasciitis per 1000 person-years, while controlling for sex, race, rank, service, and age.

Results: The overall unadjusted incidence rate of plantar fasciitis was 10.5 per 1000 person-years. Compared with men, women had a significantly increased adjusted incidence rate ratio for plantar fasciitis of 1.96 (95% confidence interval, 1.94 to 1.99). The adjusted incidence rate ratio for black service members compared with white service members was 1.12 (95% confidence interval, 1.09 to 1.12). With junior officers as the referent category, junior enlisted, senior enlisted, and senior officer rank groups had a significantly increased adjusted incidence rate ratio for plantar fasciitis: 1.20 (95% confidence interval, 1.18 to 1.23), 1.19 (95% confidence interval, 1.17 to 1.22), and 1.56 (95% confidence interval, 1.52 to 1.61), respectively. Compared with service members in the Air Force, those in the Army and Marines had a significantly increased adjusted incidence rate ratio for plantar fasciitis of 1.85 (95% confidence interval, 1.82 to 1.87) and 1.28 (95% confidence interval, 1.25 to 1.30), respectively. The adjusted incidence rate ratio for the age group of forty years old or more compared with the twenty to twenty-four-year-old group was 3.42 (95% confidence interval, 3.34 to 3.51).

Conclusions: Female sex; black race; junior enlisted, senior enlisted, and senior officer rank groups; service in the Army or Marines; and increasing age are all risk factors for plantar fasciitis.