Mechanisms, Injury Patterns and Biomechanical Factors of Anterior Cruciate Ligament Injuries in Football (Soccer): A...

To date, several studies have characterised the mechanisms, injury patterns and biomechanical factors leading to anterior cruciate ligament (ACL) injuries in football (soccer). However, varying methodologies have resulted in differing findings and outcomes.

We aimed to provide a clearer understanding of the mechanisms, injury patterns and biomechanical factors that may pose a higher risk of ACL injury in football players, we conducted a meta-analysis of studies that used video analysis as their primary research tool.

Five databases (PubMed, Web of Science, Embase, Scopus and SPORTDiscus) were searched from inception to September 2024 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The population, exposure and outcome framework were used to formulate eligibility criteria. Cohort studies of male and female football players reporting mechanisms, injury patterns and/or biomechanical factors of ACL injury examined by video analysis were included. A subsequent meta-analysis was performed to calculate odds ratios (ORs) and frequencies for the different patterns leading to ACL injury.

Thirteen studies published between 2015 and 2024 were included with a total of 709 participants. Ten studies focused on male players, two on female players and one study included both. Regarding mechanisms, non-contact ACL injuries were more likely than direct contact (OR = 5.75, 95% confidence interval [CI] 2.28-14.53, p < 0.001, I² = 88%) and indirect contact (OR = 3.32, 95% CI 1.88-5.86, p < 0.001, I² = 74%). Anterior cruciate ligament injuries were more common during defending actions compared with attacking actions (OR = 2.51, 95% CI = 1.23-5.08, p < 0.001, I² = 88%) and without ball possession than with ball possession (OR = 2.31, 95% CI 1.01-5.29, p = 0.05, I² = 75%). Particularly, the frequency of ACL injuries while pressing/tackling was significantly higher than the rest of the actions (p < 0.001). Regarding biomechanical factors, ACL injuries were more common when players were on single-leg support compared with double-leg support (OR = 9.66, 95% CI 6.97-13.39, p < 0.001, I² = 0%). Anterior cruciate ligament injuries often involved complex multiplanar interactions, with a predominance of knee flexion (range from 26° ± 10° at initial contact to 39 ± 11° at the injury frame) along with a consistent knee valgus pattern at the injury frame (79% of the cases; χ² = 33.32, p < 0.001).

A comprehensive review of video-analysis studies on ACL injuries in football reveals that the most common injury pattern involves a defending action performed on single-leg support, without ball possession, and occurring through a non-contact mechanism. Still, the review reflects that the mechanism of ACL injury in football is complex and should be interpreted holistically rather than in isolation.

The protocol for this systematic review was registered a priori in the INPLASY database (registration number INPLASY202420026).