Associations Between Sport Specialization, Running-Related Injury, and Menstrual Dysfunction Among High School Distance Runners.

Purpose: To determine the associations between sport specialization, running-related injury, and menstrual dysfunction in high school distance runners. Methods: A total of 126 female runners competing in crosscountry and distance track events in southern California during the 2003-2004 interscholastic sport seasons were prospectively followed. Baseline questionnaires assessed sport participation, menstrual history, demographic characteristics, and anthropometric measurements. Low back and lower extremity musculoskeletal running-related injuries were recorded using daily injury reports. Results: Fifty-seven (45.2%) runners incurred at least one musculoskeletal running-related injury. At baseline, 27 (21.4%) runners were highly specialized athletes, 38 (30.2%) were moderate specialization athletes, and 61 (48.4%) were low specialization athletes. Compared to low specialization athletes, the risk of musculoskeletal running-related injury was 75% greater (relative risk = 1.75; 95% confidence interval [CI]: 1.1 to 2.7) and menstrual dysfunction was four times more likely in highly specialized athletes (relative risk = 4.22; 95% CI: 1.7 to 10.8). Conclusions: High sport specialization was associated with increased running-related injury risk and menstrual dysfunction in female interscholastic runners. [ABSTRACT FROM AUTHOR]