Hamstrung: Do Sex Differences in Hamstring Injury Profile Necessitate a Different Approach to Rehabilitation and Prevention Programs in Female Athletes?

Hamstring strain injury (HSI) is one of the most common injuries encountered in running sports and can lead to significant morbidity, with time lost from participation and high rates of recurrence.  Though the incidence is high in both sexes, male athletes appear to have a two to four-fold greater risk of HSI compared to female athletes, with a longer recovery.  Multiple potential risk factors have been studied and age, history of hamstring injury, ACL injury and calf injury appear to be the most significant factors in predicting index injury and recurrence.  Female athletes may be relatively protected by less hamstring unit stiffness and greater muscle endurance.  Other potential sex-influenced risk factors including differences in pelvic, hip and knee structural morphology and limb alignment, musculotendinous flexibility and joint mobility, and kinetic chain (primary posterior) strength imbalances require further investigation.  Further research focusing both exclusively on female athlete as well as more robust comparative studies with male athletes will help us to better understand differences in HSI profile.  Future investigation is necessary to determine whether a sex-specific approach to HSI rehabilitation and prevention programs will optimize clinical care for both male and female athletes.