Thursday Night Football's impact on all-cause injuries in NFL players during 2012 - 2017

Analysis of Concussions Reported in American Professional Football Injury Reports in the 2019 Through 2023 Regular Seasons

OBJECTIVE

The National Football League (NFL) has seen increasing scrutiny regarding its management of concussions, especially following an on-field incident involving the Miami Dolphins' quarterback Tua Tagovailoa in the 2022 season. We hope to elucidate the recent trends in the diagnosis and management of concussions during the course of 5 NFL seasons from 2019 to 2023.

METHODS

We queried the NFL injury reports from the 2019 through 2023 database recording players listed with concussions. The weeks missed were calculated using the NFL game logs. Players' concussions that did not occur in the games, those complicated by other injuries, and those affected by roster status were excluded.

RESULTS

Searches of the NFL injury reports resulted in the identification of 664 of 692 concussions (96%) that occurred in regular season games across the 2019-2023 seasons. During the course of these 5 seasons, 31% of the players returned without missing a game, 39% of the players missed 1 game, and 30% of the players missed ≥2 games. No significant difference in the number of concussions per game or weeks missed was observed across the seasons observed. Players with concussions on teams that made the playoffs saw fewer weeks missed than those on non-playoff teams (0.86 vs. 1.37; P = 0.002).

CONCLUSIONS

Since the start of the 2021 NFL season, an increasing incidence of concussions has been noted; however, there was no change observed in the number of weeks missed after the concussions. Trends in the rates of concussions across the seasons remain largely stable, despite increased scrutiny over concussions in the sport.

Association of Injury Rates Among Players in the National Football League With Playoff Qualification, Travel Distance, Game Timing, and the Addition of Another Game: Data From the 2017 to 2022 Seasons

Background

Injury incidence is higher in the National Football League (NFL) than in other collision sports. Although previous research has identified that scheduling variations, including overseas games and bye week timing, does not affect concussion risk, data are currently lacking regarding the effects of scheduling variation on season-long musculoskeletal injury incidence.

Purpose

To determine whether higher cumulative travel distance, overseas play, an early season bye week, and an expansion of the regular season is associated with higher injury rates in the NFL.

Study Design

Descriptive epidemiology study.

Methods

All 1275 injuries across 5 NFL seasons from 2017 to 2018 through 2021 to 2022 were reviewed retrospectively. Injury data and travel distances were extracted from publicly available sources, which were cross-referenced for validation. Injury rates were calculated per 1000 athletic-exposures (AEs). Cumulative team travel distances were compared statistically using a linear regression. Single factor analysis of variance was used to compare categorical variables.

Results

Travel distance did not significantly predict injury rates (P = .47), and there was no difference in injury rates between teams that played a game overseas versus teams that did not (19.3 injuries per 1000 AEs for both; P = .96). In addition, no difference was found in injury rates (F[109,2100[ = 0.704; P = .73) or players placed on the injured reserve list (F[99,778] = 1.70; P = .077) between various bye weeks (P = .73). Injury rates did not differ between the new 17-game regular season (18.4 per 1000 AEs) versus the previous four 16-game regular seasons (19.7 per 1000 AEs; P = .12). However, teams that did not qualify for the playoffs had a significantly higher injury rate (19.9 per 1000 AEs) as well as players on injured reserve (8.0 per 1000 AEs) than playoff-qualifying teams (18.4 and 6.8 per 1000 AEs, respectively; P < .05 for both).

Conclusion

Over 5 NFL seasons, cumulative travel distance, overseas play, bye week timing, and adding 1 regular season game were not associated with increased injury rates in NFL players. However, a lack of regular season success was associated with higher injury rates and more players on injured reserve.

Concussions Increase the Odds of Lower-Extremity Injuries in National Football League Players: Four-Year Review of Publicly Available Data

Objective

Methods

Results

Conclusions

Level of Evidence

Validity of Research Based on Public Data in Sports Medicine: A Quantitative Assessment of Anterior Cruciate Ligament Injuries in the National Football League

BACKGROUND

Numerous researchers have leveraged publicly available Internet sources to publish publicly obtained data (POD) studies concerning various orthopaedic injuries in National Football League (NFL) players.

PURPOSE

To provide a comprehensive systematic review of all POD studies regarding musculoskeletal injuries in NFL athletes and to use anterior cruciate ligament (ACL) injuries in NFL players to quantify the percentage of injuries identified by these studies.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review was conducted to identify all published studies utilizing POD regarding ACL injury in NFL athletes from 2000 to 2019. Data regarding player demographics were extracted from each publication. These results were compared with prospectively collected data reported by the teams' medical staff to the NFL Injury Surveillance System database linked to the League's electronic health record. An ACL "capture rate" for each article was calculated by dividing the number of ACL injuries in the POD study by the total number of ACL injuries in the NFL injury database occurring in the study period of interest.

RESULTS

A total of 42 studies were extracted that met the definition of a POD study: 28 evaluated a variety of injuries and 14 dealt specifically with ACL injuries, with 35 (83%) of the 42 studies published during or since 2015. POD studies captured a mean of 66% (range, 31%-90%) of ACL injuries reported by the teams' medical staff. This inability to capture all injury rates varied by position, with 86% capture of ACL injuries in skill athletes, 72% in midskill athletes, and 61% in linemen. POD studies captured 35% of injuries occurring during special teams play.

CONCLUSION

The frequency of studies leveraging publicly obtained injury data in NFL players has rapidly increased since 2000. There is significant heterogeneity in the degree to which POD studies correctly identify ACL injuries from public reports. Sports medicine research relying solely on publicly obtained sources should be interpreted with an understanding of their inherent limitations and biases. These studies underreport the true incidence of injuries, with a bias toward capturing injuries in more popular players.

The Interval Between Matches Significantly Influences Injury Risk in Field Hockey

Fixture congestion increases injury risk in football, but how it impacts other sports is unclear. The aim of this study was to identify associations between match density and injury incidence in field hockey players. Injury data from a prospective cohort study of professional and youth players was analysed in two ways. Inter-match intervals were clustered into<2424-hours, 3–7-days, and 13 + days, and injury rate ratios (IRR) were calculated to identify differences between clusters in match injuries. Separately, a Lasso-penalised Poisson regression model was used to determine the association between match load across the previous 24-hours, 3-days, 7-days and 14-days, and match and training injuries. Injury rates in matches within 24-hours of the previous match were mostly significantly higher when compared to matches after 3–7-days (IRRs: 3.78; 6.77, P = 0.003; 0.005). While a higher match exposure in the preceding 24-hour and 3-day periods was associated with higher combined match and training injury rates (β̂ = 0.0001; 0.0018), a higher match exposure in the previous 7-and 14-day periods was associated with a reduced injury rate (β̂ = –0.0001; –0.0005). Due to the increased injury risk in matches 3-days and especially 24-hours following the previous fixture, match distribution should be cautiously planned.

Game Spacing and Density in Relation to the Risk of Injuries in the National Hockey League

Background

Ice hockey has significant workload demands. Research of other sports has suggested that decreased rest between games as well as an increased workload may increase the risk of injuries.

Purpose

To evaluate whether condensed game schedules increase the frequency and severity of injuries in the National Hockey League (NHL).

Study Design

Descriptive epidemiology study.

Methods

Data were obtained from publicly available online sources on game schedules and injuries for all NHL teams for the 2005-2006 through 2018-2019 seasons. Injury rates (per team per game) and the proportion of severe and nonsevere injuries were determined. The game-spacing analysis assessed the risk of injuries in relation to the number of days between games played (range, 0-≥6 days). The game-density analysis assessed the risk of injuries in relation to the number of games played within 7 days (range, 1-5 games). Results were assessed by analysis of variance, the post hoc Tukey test, and the chi-square test of distribution.

Results

The game-spacing analysis included 33,170 games and 7224 injuries, and a significant group difference was found (P = 1.44×10^-5), with the post hoc test demonstrating an increased risk of injuries when games were spaced with <1 day of rest. There was no significant difference in the ratio of severe to nonsevere injuries. The game-density analysis included 33,592 games and 10,752 injuries, and a significant group difference was found (P = 8.22×10^-48), demonstrating an increased risk of injuries with an increased number of games in all conditions except for the comparison between 4 versus 5 games in 7 days. There was also a significant difference in injury severity (P = .008), indicating that the least dense condition had a higher ratio of severe to nonsevere injuries compared with the other game-density conditions. Finally, the game-density analysis was repeated after excluding games played with <1 day of rest, and the finding of increased injury rates with increasingly condensed schedules remained significant (P = 9.52×10^-46), with significant differences between all groups except for the comparison between 1 versus 2 games in 7 days.

Conclusion

We found that a condensed schedule and <1 day of rest between games were associated with an increased rate of injuries in the NHL. These findings may help in the design of future game schedules.

Evaluation of Musculoskeletal Re-Injury Occurrence in Previously Concussed National Football League Athletes

Introduction

Increased risk of musculoskeletal (MSK) injury post-concussion has been reported in collegiate athletes, yet it is unknown if professional football athletes are at the same risk of secondary injury. The objective of this study was to determine if the risk of MSK injury in National Football League (NFL) athletes increases after concussion.

Methods

NFL injury reports from 2013 to 2017 were collected from public websites. Concussed athletes (n=91) were equally matched to a non-injured control and an athlete with an incident of musculoskeletal (MSK) injury.

Results

Following their return to sport, concussed athletes were 2.35 times more likely to have a subsequent MSK injury relative to non-injured controls (95% CI: 2.35 [1.25, 4.44], P = 0.01), but were no more likely than athletes with an incident MSK injury (P = 0.55). Likewise, athletes with an incident MSK injury were no more likely to have a subsequent MSK injury than controls (P = 0.08).

Discussion

Increased odds of MSK injury in the 12-week period following a concussion in professional football athletes warrants future research on the acute effects of concussion and the relationship to MSK injury risk.