Date of Completion

Spring 5-1-2020

Thesis Advisor(s)

Kristin Morgan

Honors Major

Biomedical Engineering


Biomechanics and Biotransport


Anterior cruciate ligament (ACL) injuries are among the most common injuries experienced by athletes in the United States. Even after reconstruction surgery individuals have been known to develop complications much later in life, including long-term or permanent alterations to their gait, which may lead to early-onset knee osteoarthritis. This thesis work sought to define these alterations as they pertain specifically to running. Using results and parameters from previous studies, the goal of this study is to compare muscle force production strategies, as they relate to ACL force and strain, of injured and non-injured individuals. These values, muscle forces and ACL forces and strains, were obtained using OpenSim, which is a free computational modeling software developed by Stanford University. Running trials were broken down into cycle phases, and force and strain values were analyzed as such. After averages were calculated for the injured and non-injured groups, two-sample t-tests were performed to determine significant differences between the two groups for each gait phase. After analysis of the results, it was found that there were significant differences between the two groups concerning muscle force production strategies but not concerning ACL forces and strains. However, injured subjects experienced higher peak force on the ACL at the second peak of motion as opposed to the first peak at which the non-injured group experienced a higher peak force. Therefore, because of the significant differences in muscle force production strategies and peak force values, it can be said that injured individuals adopt an altered pattern of running when compared to non-injured individuals. However, based on this investigation, no correlations between muscle force production and ACL force and strain can be defined. A larger sample size must be employed to confirm these results.