Video Analysis of Anterior Cruciate Ligament Injuries in National Basketball Association Athletes.

PURPOSE

Research surrounding the biomechanics and video analysis of anterior cruciate ligament (ACL) injuries at the professional level has emerged in recent years as a tool to screen athletes for potential biomechanical deficits. The purpose of this study was to analyze and discuss the most common mechanism, body position, and activity at the time of ACL injury among NBA players.

METHODS

Anterior cruciate ligament injuries over 10 consecutive NBA seasons (2009-2010 to 2019-2020) were reviewed from publicly available sources. A 10-question survey was developed and utilized to analyze each video clip. These questions were divided into three categories: 1. contact mechanism, 2. activity at the time of injury, and 3. position of the involved lower extremity at the time of injury. Two reviewers analyzed the videos individually, and differing answers were resolved via consensus review, with a senior author arbitrating in the case of any discrepancies.

RESULTS

Overall, 23 ACL ruptures were included. The most common injury mechanism was indirect contact with another player without knee contact (56.5%), and no patients had an ACL rupture as a result of direct knee contact with another player. The most common action at the time of injury was pivoting (47%), and the most common basketball action was dribbling (43.5%). Additionally, the vast majority of patients were injured while on offense (91.3%). The most common knee positions were early flexion (73.9%) and abduction (95.7%). The most common foot positions were abduction relative to the knee (82.6%), in eversion (73.9%), and dorsiflexion (56.5%). The most common hip position was early flexion (87%), and all hips were abducted (100%).

CONCLUSION

Our study found that the majority of ACL ruptures occurred during offensive play and over half were secondary to contact with an opposing player (but without a direct blow to the injured knee), indicating that such perturbations may alter the kinematics of the players' movement. Additionally, a large majority of ACL injuries occurred while the hip was abducted with the knee in abduction relative to the hip and while the knee was in early flexion from 0° to 45°.