Sport Specialization Elevates Risk for Lower Extremity Stress Fractures in Female Military Cadets

Monday, July 13, 2020



DALLAS, TX – New research suggests that prior sports specialization is associated with an increased risk of a lower extremity stress fracture in female U.S. Service Academy cadets, but not males during their first year of service. The study, Prior Sport Specialization is Associated With Lower Extremity Stress Fracture in Female Service Academy Cadets is being presented today as part of the 2020 NATA Virtual Clinical Symposia & AT Expo’s educational programming, which transitioned to a virtual event in light of COVID-19. The study abstract will be published in the Journal of Athletic Training, the scientific journal of the National Athletic Trainers’ Association, later this year.

The study found that females were over five times more likely to experience an incident stress fracture (4.47%) when compared to males (0.84%). The investigators observed a dose dependent relationship between the level of prior sport specialization and the likelihood of lower extremity stress fracture.  In univariate models, females with moderate specialization were 2.49 times more likely to sustain an incident lower extremity stress fracture and those with high specialization were 4.25 times more likely when compared to those with low specialization, however only the later was statistically significant. Similar results were observed in multivariable models controlling for weight, injury history, and lower extremity movement quality at baseline.

“Like many athletes, first-year cadets undergo rigorous physical activity and they are at increased risk for overuse injuries like stress fractures. Understanding how prior level of sport specialization is associated with the risk of these injuries during military training can provide insight into opportunities for injury prevention and risk mitigation,” said Kenneth Cameron, Ph.D., MPH, ATC, director of Orthopedic and Sports Medicine Research at Keller Army Hospital: John A. Feagin Jr. Sports Medicine Fellowship.

Dr. Cameron also noted “Previous studies have reported that females in high school were more likely to participate at high competition volume, participate on a club team, and be highly specialized which was associated with an increased risk of lower extremity injury.  This may continue to impact these athletes after high school graduation, particularly in female service academy cadets.”

A total of 2,012 participants from the freshman class of 2020 and 2021 consented (470 females, 23.4%) and agreed to participate in this study. Those that consented completed a baseline questionnaire that included demographic information, lower extremity injury history and standard items on level of sports specialization using the 3-point Jayanthi scale.  The subjects were followed during their first year at the academy to identify all incident lower extremity stress fractures.

Among all participants, 881 (43.78%) reported low specialization, 729 (36.23%) reported moderate specialization and 402 (19.98%) reported high levels of sports specialization at baseline.  During the one-year follow-up period, 34 incident lower extremity stress fractures were identified in the cohort and the cumulative incidence was 1.69%.

About NATA: National Athletic Trainers’ Association – Health Care for Life & Sport

Athletic trainers are health care professionals who specialize in the prevention, diagnosis, treatment and rehabilitation of injuries and sport-related illnesses. They prevent and treat chronic musculoskeletal injuries from sports, physical and occupational activity, and provide immediate care for acute injuries. Athletic trainers offer a continuum of care that is unparalleled in health care. The National Athletic Trainers' Association represents and supports 45,000 members of the athletic training profession.  Visit for more information.