National Football League (NFL) "Dynamic Kickoff" Rule Change: A Comparative Analysis of Concussion and...

Kickoffs in the National Football League (NFL) are historically one of the most dangerous plays during an NFL game, with high levels of injuries. In 2024, the NFL introduced new rules aimed at reducing injuries during kickoffs, enhancing player safety, and increasing the frequency of kick returns.

To evaluate whether the NFL kickoff rule changes in 2024 had any effect on the incidence of injuries, particularly with a focus on concussions.

Descriptive epidemiology study.

Injuries on kickoffs were identified for the 2022, 2023, and 2024 NFL seasons using the transcribed game book for each game on the official NFL website. Injury type was confirmed using the injury report on each team's website for the following week. If an injury was unreported on the subsequent injury report, it was listed as an unspecified injury. Injuries were defined as neuromusculoskeletal complaints documented in the game book for kickoffs and confirmed in the subsequent week's injury report. The injury rate was calculated annually for each injury category by analyzing injury incidence relative to the number of kickoffs and returns, with each analyzed separately. The incidence rate ratio (IRR) was calculated by dividing the IRR of one season by that of another season. Also, 95% CIs for the IRR were calculated, and P values were determined using the exact Poisson method.

This epidemiological study found that a comparison of the 2024 versus 2022 season showed a statistically significant increase in the overall number of injuries (IRR, 1.10 [95% CI, 1.08-1.11]); P < .001), upper extremity injuries (IRR, 6.74 [95% CI, 6.30-7.21]; P < .001]), and lower extremity injuries (IRR, 2.20 [95% CI, 2.14-2.26]; P < .001), when analyzed by the number of kickoffs. This study found that a comparison of the 2024 versus 2022 season showed a statistically significant increase in the overall number of injuries (IRR, 1.25 [95% CI, 1.23-1.27]; P < .001), upper extremity injuries (IRR, 7.69 [95% CI, 7.20-8.23]; P < .001), and lower extremity injuries (IRR, 2.51 [95% CI, 2.44-2.58]; P < .001), when analyzed by the number of returns. However, when comparing the 2024 and 2022 NFL seasons, 2024 saw a statistically significant decrease in the incidence of concussions when analyzed by both kickoffs (IRR, 0.77 [95% CI, 0.74-0.80]; P < .001) and returns (IRR, 0.88 [95% CI, 0.84-0.92]; P < .001). When compared with the 2023 NFL season, the 2024 NFL season showed a statistically significant rise in overall injuries (IRR, 1.59 [95% CI, 1.56-1.61]; P < .001), lower extremity injuries (IRR, 2.57 [95% CI, 2.49-2.64]; P < .001), upper extremity injuries (IRR, 2.24 [95% CI, 2.15-2.34]; P < .001), and concussions (IRR, 3.85 [95% CI, 3.59-4.13]; P < .001) when analyzed by kickoffs. When the 2023 NFL season was compared with the 2024 NFL season, it showed a statistically significant rise in overall injuries (IRR, 1.05 [95% CI, 1.03-1.07]; P < .001), lower extremity injuries (IRR, 1.70 [95% CI, 1.65-1.75]; P < .001), upper extremity injuries (IRR, 1.49 [95% CI, 1.43-1.55]; P < .001), and concussions (IRR, 2.25 [95% CI, 2.38-2.74]; P < .001) when analyzed by returns. When the 2023 season was compared with the 2022 season, there was a statistically significant decrease in the number of concussions when analyzed by both kickoffs (IRR, 0.20 [95% CI, 0.19-0.21]; P < .001) and returns (IRR, 0.31 [95% CI, 0.29-0.34]; P < .001).

Our study showed that after the 2024 NFL kickoff rules were implemented, there was a significant increase in overall, lower extremity, and upper extremity injuries compared with the previous 2 seasons, as measured by the number of kickoffs and returns per year. The overall effect of the 2024 NFL kickoff rules on the incidence of concussions remains unclear when compared with the previous 2 seasons, as there was an increase in the incidence of concussions compared with 2023 and a decrease in the incidence of concussions compared with 2022. The kickoff remains an essential component of the game and still presents a challenge, as it is a play with a high injury rate.