Observation of risk for concussion following ‘lowering the helmet to initiate contact’ penalties in the NFL

Objective: This observational study examines the associated risk for concussion following ‘lowering the helmet to initiate contact’ penalties in the National Football League. Methods: Using officially published injury data on the National Football League (NFL) website, the authors reviewed NFL Players diagnosed with a concussion from 2015 to 2022 and who received a ‘lowering the helmet to initiate contact’ penalty from 2018 to 2020. Reported concussions were evaluated for association with ‘lowering the helmet to initiate contact’ penalties. The Friedman test assessed overall differences between the years. Pairwise comparisons were performed using the Wilcoxon signed-rank test with a Bonferroni correction to adjust for multiple comparisons. Results: The average incidence of all concussions per play was 0.45% for regular-season games. From 2018 to 2020, 86 lowering the helmet to initiate contact penalties were called. Three of 86 penalties resulted in concussions, with a 3.5% incidence. The Friedman test indicated significant differences in concussion trends across the years (χ2 = 16.0, p = 0.0003). Pairwise analysis with the Wilcoxon signed-rank test and adjusted for multiple comparisons with a Bonferroni correction (α = 0.05/28 = 0.0018) showed no statistically significant differences between years. There was a significant negative correlation of overall concussion incidence per year. Conclusions: The incidence of concussion with players penalized for lowering the helmet to initiate contact is greater than the overall incidence of concussions in all plays. While there is no difference in total concussions that occur, the concussion rate has a significant negative trend between 2015 and 2022. However, it is difficult to analyze the nonimmediate effects of this penalty on players’ intended play and practice, which may further decrease concussions.