Sex-based Differences in Hamstring Injury Risk Factors

Hamstring injuries (HSI) are common in a number of different sports and can confer a significant burden to both male and female athletes. Though research on HSIs in the female athlete population is lacking, current literature suggests male athletes are between two to four times more likely than female athletes to sustain an HSI. Despite this discrepancy, the role of intrinsic sex differences in HSI risk factors has not been previously explored. This review aims to summarize these sex-based differences in HSI risk factors and their influence on the lower rate of HSIs seen in female athletes as compared to male athletes. Women exhibit increased hamstring flexibility and decreased hamstring musculotendinous stiffness as compared to men; women are also shown to be more resistant to skeletal muscle fatigue. Sex differences in the hamstring to quadriceps ratio and certain lower limb morphologies may also contribute to the sex discrepancy in HSI rates. This remains an area for future research in order to understand the multifaceted nature of HSI injury risk factors and optimize HSI rehabilitation and prevention programs for both male and female athletes.