Player Tracking Metrics to Predict Risk of Anterior Cruciate Ligament Injuries During Change-of-Direction Scenarios...

National Football League (NFL) athletes face a substantial risk for anterior cruciate ligament (ACL) injuries, particularly during special team plays. ACL injuries commonly occur during change-of-direction (CoD) scenarios. Player tracking is standardized for all NFL games and can be used to quantify player motion intensity during CoD injury scenarios.

The purpose was to identify ACL injuries during CoD scenarios in the NFL. We investigated whether player tracking metrics derived from on-field play can predict an increased ACL injury risk during CoD scenarios.

Descriptive epidemiology study.

For all ACL injuries (n = 216) occurring in games during the 2018 to 2022 NFL seasons, the injury timing and injury scenario were identified through a video review. Motion characteristics of ACL injuries during CoD scenarios were identified from player tracking data, and a generalized linear mixed model (GLMM) was developed to quantify whether player tracking metrics were predictive of the ACL injury risk during CoD scenarios.

Among the ACL injuries reviewed, 32% were noncontact, 42% were indirect contact, and 46% were classified as CoD scenarios. Of the athletes involved in a CoD scenario, 98% were decelerating at the time of their ACL injury. Maximum speed (odds ratio, 1.52 per 1-m/s increase in maximum speed) and normalized maximum deceleration power (odds ratio, 1.08 per 1-W/kg increase in maximum deceleration power) were both significant predictors of the CoD ACL injury risk. Punt and kickoff returns had a significantly increased CoD ACL injury risk only when maximum speed and normalized maximum deceleration power metrics were excluded from the GLMM.

ACL injuries in NFL games primarily occurred during CoD scenarios. Player tracking data analyzed for CoD ACL injuries demonstrated a consistent movement pattern involving high speeds and deceleration at the time of the injury. Both a player's maximum speed and normalized maximum deceleration power were significant predictors of an increased CoD ACL injury risk. The inclusion of these metrics in a GLMM helped to explain the variation in CoD ACL injury rates observed across different play types.