Risk Factors for Lower Extremity Tendinopathies in Military Personnel

BACKGROUND Overuse injuries have a significant impact on United States military service members, but research to date has been limited in its ability to assess occupational and behavioral risk factors. HYPOTHESIS/PURPOSE To prospectively identify risk factors for the development of lower extremity tendinopathy and plantar fasciitis in United States military personnel. STUDY DESIGN Descriptive epidemiology study. METHODS Baseline data from the Millennium Cohort Study, a long-term observational cohort of military personnel, were utilized. Service members were enrolled in the cohort in 2001, 2004, and 2007. A total of 80,106 active-duty personnel were followed over 1 year for the development of patellar tendinopathy, Achilles tendinopathy, and plantar fasciitis. Regression analyses were used to estimate significant associations between each tendinopathy, plantar fasciitis, and demographic, behavioral, and occupational characteristics. RESULTS Using medical records, 450 cases of Achilles tendinitis, 584 cases of patellar tendinopathy, and 1228 cases of plantar fasciitis were identified. Recent deployment was associated with an increased risk for developing plantar fasciitis (adjusted odds ratio [AOR], 1.27; 95% confidence interval [CI], 1.04-1.56). Moderate weekly alcohol consumption was marginally associated with an increased risk for Achilles tendinopathy (AOR, 1.33; 95% CI, 1.00-1.76). Overweight or obese individuals were more likely to develop Achilles tendinopathy and plantar fasciitis. CONCLUSION Lower extremity tendinopathies and plantar fasciitis are common among military service members, and this study identified several modifiable risk factors for their occurrence. These potential risk factors could serve as the focus for future preventive and intervention studies.