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Potential mechanisms of non-contact anterior cruciate ligament injury: The gender bias

Christine D Pollard, University of Massachusetts Amherst


It has been reported that female athletes are 4 to 6 times more likely to sustain a non-contact anterior cruciate ligament injury than their male counterparts. The purpose of this series of investigations was to investigate the influence of gender on anterior knee laxity; lower extremity joint kinematics and kinetics; and lower extremity coupling variability. For the first investigation anterior knee laxity data were collected from 12 male and 12 female athletes pre- and post-exercise across multiple data collection sessions. In addition, serum estrogen and progesterone was measured across data collections for the female subjects. For the second and third investigations three-dimensional kinematic and kinetic data were collected from the hip and knee joints of 12 female and 12 male collegiate soccer players while performing an unanticipated cutting maneuver. The first investigation revealed that there was no relationship between anterior knee laxity and acute changes in circulating estrogen and progesterone. However, females exhibited greater laxity than did males both pre- and post-exercise. Males and females demonstrated equivalent increases in laxity associated with exercise. These increases in laxity following exercise resulted in the females exhibiting more laxity than the males ever reached. This increased laxity may suggest that the female athlete does not obtain equivalent stabilization from their knee ligaments as their male counterparts. The second investigation revealed that male and female collegiate soccer players demonstrated similar hip and knee joint kinematics and kinetics while performing an unanticipated cutting maneuver. This lack of differences suggests that the collegiate athlete's acquired training and exposure to sport results in more similar mechanics between genders. In the final experiment females exhibited decreased variability in the thigh/leg rotation coupling as well as in the hip rotation/knee abduction-adduction coupling during the cutting maneuver. If females are exhibiting inflexible coordination patterns during high-level competition as compared to males, they may have decreased ability to adapt to the frequent external perturbations incurred during play. These external perturbations applied to an inflexible system may result in acute injury or may lead to repetitive micro-trauma to the ligament resulting in a predisposition to non-contact ACL injury.

Subject Area


Recommended Citation

Pollard, Christine D, "Potential mechanisms of non-contact anterior cruciate ligament injury: The gender bias" (2003). Doctoral Dissertations Available from Proquest. AAI3110544.