A biomechanical interpretation of the non-contact anterior cruciate ligament injury

Using readily available video footage of anterior cruciate ligament (ACL) injuries, captured during televised sporting events, combined with the current knowledge of knee and ACL biomechanics, a novel theoretical description of the mechanism of the injury is developed. It is proposed that the non-contact ACL injury mechanism involves a combination of three factors: (1) a dual-planar eccentric loading of the knee in single-limb-supported landing, (2) extremely rapid quadriceps contraction, and (3) the antagonistic nature of the lines of action between the patella tendon and ACL.