Comprehensive Osteopathic Medical Licensing Examination (COMLEX USA) Practice

The anterior cruciate ligament (ACL) is most commonly injured from a non-contact mechanism, particularly through a valgus strain. This usually occurs when an athlete is changing direction rapidly or landing from a jump, where the knee experiences a combination of valgus stress (a force that moves the knee inward) and rotation. This mechanism not only places tension on the ACL but can also cause it to stretch beyond its normal range, leading to a tear. While direct blows to the knee and twisting injuries can certainly result in ACL injuries, they are less common compared to the non-contact mechanisms. Repetitive stress from jumping could contribute to other knee injuries, but it is not typically associated with acute ACL injuries. The prevalence of non-contact, valgus strains highlights the importance of preventive training and conditioning in athletes who engage in sports that require frequent changes in direction or jumping.