Lewis Honors College Capstone Collection

Year of Publication





Kinesiology and Health Promotion

Degree Name

B.S. in Kinesiology

First Capstone/Thesis Advisor

Ben Johnson


Introduction: Females are consistently found to be at a higher risk of tearing their ACL. Extensive research has been completed previously to determine what causes an ACL tear and why this separation exists but a confirmed conclusion has not been found. Potential extrinsic factors such as decreased knee flexion and increased valgus have commonly been suggested as increased stressors on the ACL. The focus of this study is to determine if there is a significant difference in these two factors between males and females.

Methods: Seven healthy and highly trained subjects between the ages of 17 and 18 who do not have a history of anterior cruciate ligament injury. Three trials of the subject stepping off a 63.5 centimeter bleacher and landing naturally. Frontal and sagittal plane filmed. One trial chosen to be digitized and analyzed with MaxTRAQ software. Specifically, knee flexion and valgus angles were measured with the software at initial contact of the landing and for maximum angle.

Results: Females landed with more knee flexion at initial contact and more valgus at initial contact. Maximum knee flexion angles were only slightly different. When comparing maximum valgus, females exhibited more than males. Significant difference was not found among males and females for knee flexion. Female valgus angles were found to be significantly different than male valgus angles.

Discussion: Results comparable with current research pertaining to valgus data. Knee flexion results differ. Important for understanding ACL risk of future athletes and the potential for training interventions.

Conclusion: Original hypothesis found to be incorrect. Only a significant difference in valgus angle was found. Additional research with more subjects is needed to determine accuracy of results.