Date of Award

Spring 2002

Document Type



Life & Environmental Sciences

First Advisor

Jacqueline Brehe

Second Advisor

Gerald Shields

Third Advisor

Murphy Fox


Female athletics are increasing in popularity around the world, and with this increase in female participation in sports there has also been an increase in knee injuries. Studies have indicated that female athletes participating in soccer and basketball are two and four times, respectively, more likely to sustain a knee injury than their male counterparts. The monthly fluctuating hormone levels that occur during the reproductive years of a female have been targeted as one of the causative agents for this higher prevalence. Estrogen receptors have been identified in tissues of males including the medial collateral ligament (MCL) and the anterior cruciate ligament (ACL). The purpose of this study was to measure the effects of 17-b-estradiol on the stretch of the medial collateral ligament (MCL) and the failure load in ovariectomized female rats and orchiectomized male rats. Intact male rats were also used in this study to determine if testosterone had any effect upon the response to estrogen. Estrogen did not have a significant effect on the breaking points or the stretch of the ligaments in any of the experimental groups. These results differ from an earlier study that reported that estrogen significantly increased the stretch, as well as a study that concluded that estrogen treatment caused a significant decrease in the breaking point of the rabbit anterior cruciate ligament (ACL).