Let me start by saying what this study is not investigating. It is not assessing the mechanism of injury. Instead, The aim of this study was to systematically review knee abduction kinematics and kinetics during weight-bearing activities at baseline as a possible risk factor for future ACL injury development. What they found is contrary to popular opinion.
The meta-analysis showed that there was no difference in baseline 3D knee abduction angle at initial contact, 3D peak knee abduction angle, 2D peak knee abduction angle, 2D medial knee displacement excursion (cm) or peak knee abduction moment between those who subsequently sustained an ACL injury and those who did not.
The result from this systematic review and meta-analysis revealed no association between baseline knee abduction kinematics or kinetics during vertical drop jumps or squats and the risk of sustaining a future ACL injury. Injury prevention is complicated and multi-factorial. Our bodies are resilient and designed for multiplanar movement. Oftentimes, perceived dangerous movements are perfectly safe.