Major and Minor League Baseball Hamstring Injuries: Epidemiologic Findings From the Major League Baseball Injury Surveillance System.

Background: Hamstring strains are a recognized cause of disability for athletes in many sports, but no study exists that reports the incidence and circumstances surrounding these injuries in professional baseball.

Hypothesis: Professional baseball players have a high incidence of hamstring strains, and these injuries are influenced by multiple factors including history of hamstring injury, time period within the season, and activity of base running.

Study Design: Descriptive epidemiologic study.