Non-contact anterior cruciate ligament (ACL) injury is a common serious injury among field and court sport athletes. Aspects of the core and trunk have been associated with ACL injury incidence, though the connection between the two is not well understood. The purpose of this project is to better understand this relationship through a series of experiments measuring aspects of the core as well as surrogates for ACL injury.
Specific studies in this project addressed various aspects of the relationship in unique ways. An intervention program lacking trunk-specific exercises resulted in increased peak external knee abduction moment (pEKAbM) during cutting (p=0.012) and decreased lateral trunk control (p=0.029) while an intervention program including these exercises did not significantly alter either (lateral trunk control, p=0.178; pEKAbM, p=0.116). Another study found lateral trunk lean during cutting had a significant, positive association with pEKAbM, even when controlling for speed, gender, and cutting angle (p=0.021). Finally, electromyography analysis of select core muscles revealed increased co-contraction of the L5 extensors had a significant, positive association with pEKAbM. This same study also found that an increase in the percent difference of L5 extensor activation was associated with a decrease in trunk control during an isolated task (0.014).
Combined, this project supports the hypothesis that control and movement of the core are associated with the loading conditions at the knee that have previously been linked to ACL injury risk. Future work should use these results to develop and appropriately test intervention programs for their ability to alter lateral trunk control, pEKAbM, and, ultimately, ACL injury risk.