The effects of fatigue and gender on ankle ligament laxity

Collegiate female athletes experience more knee and overuse injuries while male athletes have more ankle injuries. Gender differences in prevalence and type of athletic injury have been attributed to kinematic, hormonal, and ligament laxity differences between men and women. Ligament laxity causes decreased joint stability, altered alignment, and increased shear forces that may increase injury risk. Females have higher knee ligament laxity before and after fatigue compared to males, but few studies have addressed the influence of fatigue and gender on ankle laxity. Ankle laxity and chronic instability can alter foot kinematics, increasing injury risk (Drewes, 2009). We measured anterior drawer ankle laxity in 40 female and 10 male collegiate athletes. Subjects were measured before and after an exercise protocol that included running stairs and jumping hurdles each week for 12 weeks. We found significantly higher ankle laxity in females than males before and after fatigue (p<0.05). Fatigue and menstrual week had no significant effect on ankle laxity, and there were no gender differences in laxity change after fatigue. These data suggest ligament laxity alone cannot explain gender differences in injury rates. Fatigue protocols should more closely simulate injury kinematics to appreciate fully the influence of fatigue on ligament integrity. Research supported by the Commonwealth Health Research Board. Grant Funding Source : Commonwealth Health Research Board