Is Youth Football Safe? An Analysis of Youth Football Head Impact Data

Background: Interventions designed to reduce the risk for head impacts and concussion in youth football have increased over the past decade; however, understanding of the role of regular game play on head impact exposure among youth tackle and flag football athletes is currently limited. Purpose: To explore head impact exposure among youth tackle and flag football athletes (age range, 6-14 years) during both practices and games. Study Design: Cohort study; Level of evidence, 2. Methods: Using the Vector MouthGuard sensor, the authors collected head impact data from 524 tackle and flag youth football athletes over the course of a football season. Quantities of interest were estimated from regression models using Bayesian methods. Results: For impacts ≥10 g, a tackle football athlete had an estimated 17.55 (95% CI, 10.78-28.96) times more head impacts per practice compared with a flag football athlete (6.85 [95% CI, 6.05-7.76] and 0.39 [95% CI, 0.24-0.62] head impacts, respectively). Additionally, a tackle football athlete had an estimated 19.48 (95% CI, 12.74-29.98) times more head impacts per game compared with a flag football athlete (13.59 [95% CI, 11.97-15.41] and 0.70 [95% CI, 0.46-1.05] head impacts, respectively). Among tackle football athletes, the estimated average impact rate was 6.51 (95% CI, 5.75-7.37) head impacts during a practice and 12.97 (95% CI, 11.36-14.73) impacts during a game, resulting in 2.00 (95% CI, 1.74-2.29) times more ≥10 g head impacts in games versus practices. Tackle football athletes had 2.06 (95% CI, 1.80-2.34) times more high-magnitude head impacts (≥40 g) during a game than during a practice. On average, flag football athletes experienced an estimated 0.37 (95% CI, 0.20-0.60) head impacts during a practice and 0.77 (95% CI, 0.53-1.06) impacts during a game, resulting in 2.06 (95% CI, 1.29-3.58) times more ≥10 g head impacts in games versus practices. Because of model instability caused by a large number of zero impacts for flag football athletes, a comparison of high-magnitude head impacts is not reported for practices or games. Conclusion: This study provides a characterization of the head impact exposure of practices and games among a large population of youth tackle and flag football athletes aged 6 to 14 years. These findings suggest that a greater focus on game-based interventions, such as fair play interventions and strict officiating, may be beneficial to reduce head impact exposures for youth football athletes.

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Comparison of head impact exposure in practice drills among multiple youth football teams

Journal of Neurosurgery Pediatrics ◽

10.3171/2018.9.peds18314 ◽

2019 ◽

Vol 23 (3) ◽

pp. 381-389 ◽

Cited By ~ 4

Author(s):

Mireille E. Kelley ◽

Mark A. Espeland ◽

William C. Flood ◽

Alexander K. Powers ◽

Christopher T. Whitlow ◽

...

Keyword(s):

Open Field ◽

Linear Models ◽

Linear Acceleration ◽

Head Impact ◽

Head Acceleration ◽

Head Impacts ◽

Youth Football ◽

Impact Rate ◽

Full Speed ◽

Impact Data

OBJECTIVELimiting contact in football practice can reduce the number of head impacts a player receives, but further research is needed to inform the modification of optimal drills that mitigate head impact exposure (HIE) while the player develops the skills needed to safely play the game. This study aimed to compare HIE in practice drills among 6 youth football teams and to evaluate the effect of a team on HIE.METHODSOn-field head impact data were collected from athletes (ages 10–13 years) playing on 6 local youth football teams (teams A–F) during all practices using the Head Impact Telemetry System. Video was recorded and analyzed to verify and assign impacts to a specific drill. Drills were identified as follows: dummy/sled tackling, half install, install, install walk through, multiplayer tackle, Oklahoma, one-on-one, open field tackling, other, passing, position skill work, scrimmage, special teams, tackling drill stations, and technique. HIE was quantified in terms of impacts per player per minute (ppm) and peak linear and rotational head acceleration. Generalized linear models were used to assess differences in head impact magnitude and frequency among drills as well as among teams within the most common drills.RESULTSAmong 67 athlete-seasons, a total of 14,718 impacts during contact practices were collected and evaluated in this study. Among all 6 teams, the mean linear (p < 0.0001) and rotational (p < 0.0001) acceleration varied significantly among all drills. Open field tackling had significantly (p < 0.001) higher mean linear acceleration than all other drills. Multiplayer tackle had the highest mean impact rate (0.35 ppm). Significant variations in linear acceleration and impact rate were observed among teams within specific drills. Team A had the highest mean linear acceleration in install, one-on-one, and open field tackling and the highest mean impact rate in Oklahoma and position skill work. Although team A spent the greatest proportion of their practice on minimal- or no-player versus player contact drills (27%) compared to other teams, they had the highest median (20.2g) and 95th percentile (56.4g) linear acceleration in practice.CONCLUSIONSFull-speed tackling and blocking drills resulted in the highest HIE. Reducing time spent on contact drills relative to minimal or no contact drills may not lower overall HIE. Instead, interventions such as reducing the speed of players engaged in contact, correcting tackling technique, and progressing to contact may reduce HIE more effectively.

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Head Impact Exposure in Practices Correlates With Exposure in Games for Youth Football Players

Journal of Applied Biomechanics ◽

10.1123/jab.2017-0207 ◽

2018 ◽

Vol 34 (5) ◽

pp. 354-360 ◽

Cited By ~ 3

Author(s):

Srinidhi Bellamkonda ◽

Samantha J. Woodward ◽

Eamon Campolettano ◽

Ryan Gellner ◽

Mireille E. Kelley ◽

...

Keyword(s):

Linear Acceleration ◽

The United States ◽

Head Impact ◽

Football Players ◽

Valuable Insight ◽

Head Impacts ◽

Youth Football ◽

Exposure Profile ◽

Impact Data ◽

Insight Into

This study aimed to compare head impact exposures between practices and games in football players ages 9 to 14 years, who account for approximately 70% of all football players in the United States. Over a period of 2 seasons, 136 players were enrolled from 3 youth programs, and 49,847 head impacts were recorded from 345 practices and 137 games. During the study, individual players sustained a median of 211 impacts per season, with a maximum of 1226 impacts. Players sustained 50th (95th) percentile peak linear acceleration of 18.3 (46.9) g, peak rotational acceleration of 1305.4 (3316.6) rad·s−2, and Head Impact Technology Severity Profile of 13.7 (24.3), respectively. Overall, players with a higher frequency of head impacts at practices recorded a higher frequency of head impacts at games (P < .001,r2 = .52), and players who sustained a greater average magnitude of head impacts during practice also recorded a greater average magnitude of head impacts during games (P < .001). The youth football head impact data quantified in this study provide valuable insight into the player exposure profile, which should serve as a key baseline in efforts to reduce injury.

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Head impact exposure measured in a single youth football team during practice drills

Journal of Neurosurgery Pediatrics ◽

10.3171/2017.5.peds16627 ◽

2017 ◽

Vol 20 (5) ◽

pp. 489-497 ◽

Cited By ~ 13

Author(s):

Mireille E. Kelley ◽

Joeline M. Kane ◽

Mark A. Espeland ◽

Logan E. Miller ◽

Alexander K. Powers ◽

...

Keyword(s):

Open Field ◽

Injury Risk ◽

Linear Models ◽

Head Impact ◽

Head Impacts ◽

Wald Tests ◽

Impact Location ◽

Youth Football ◽

Football Team ◽

Impact Data

OBJECTIVEThis study evaluated the frequency, magnitude, and location of head impacts in practice drills within a youth football team to determine how head impact exposure varies among different types of drills.METHODSOn-field head impact data were collected from athletes participating in a youth football team for a single season. Each athlete wore a helmet instrumented with a Head Impact Telemetry (HIT) System head acceleration measurement device during all preseason, regular season, and playoff practices. Video was recorded for all practices, and video analysis was performed to verify head impacts and assign each head impact to a specific drill. Eleven drills were identified: dummy/sled tackling, install, special teams, Oklahoma, one-on-one, open-field tackling, passing, position skill work, multiplayer tackle, scrimmage, and tackling drill stations. Generalized linear models were fitted to log-transformed data, and Wald tests were used to assess differences in head accelerations and impact rates.RESULTSA total of 2125 impacts were measured during 30 contact practices in 9 athletes (mean age 11.1 ± 0.6 years, mean mass 44.9 ± 4.1 kg). Open-field tackling had the highest median and 95th percentile linear accelerations (24.7g and 97.8g, respectively) and resulted in significantly higher mean head accelerations than several other drills. The multiplayer tackle drill resulted in the highest head impact frequency, with an average of 0.59 impacts per minute per athlete, but the lowest 95th percentile linear accelerations of all drills. The front of the head was the most common impact location for all drills except dummy/sled tackling.CONCLUSIONSHead impact exposure varies significantly in youth football practice drills, with several drills exposing athletes to high-magnitude and/or high-frequency head impacts. These data suggest that further study of practice drills is an important step in developing evidence-based recommendations for modifying or eliminating certain high-intensity drills to reduce head impact exposure and injury risk for all levels of play.

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The Effect of Player Contact Characteristics on Head Impact Exposure in Youth Football Games

Journal of Applied Biomechanics ◽

10.1123/jab.2020-0145 ◽

2020 ◽

pp. 1-11

Author(s):

Daniella M. DiGuglielmo ◽

Mireille E. Kelley ◽

Mark A. Espeland ◽

Zachary A. Gregory ◽

Tanner D. Payne ◽

...

Keyword(s):

Injury Risk ◽

Body Position ◽

Mixed Effects ◽

Head Impact ◽

Mixed Effects Models ◽

Rotational Acceleration ◽

Head Impacts ◽

Factors Influencing ◽

Youth Football ◽

Impact Data

To reduce head impact exposure (HIE) in youth football, further understanding of the context in which head impacts occur and the associated biomechanics is needed. The objective of this study was to evaluate the effect of contact characteristics on HIE during player versus player contact scenarios in youth football. Head impact data and time-synchronized video were collected from 4 youth football games over 2 seasons in which opposing teams were instrumented with the Head Impact Telemetry (HIT) System. Coded contact characteristics included the player’s role in the contact, player speed and body position, contact height, type, and direction, and head contact surface. Head accelerations were compared among the contact characteristics using mixed-effects models. Among 72 instrumented athletes, 446 contact scenarios (n = 557 impacts) with visible opposing instrumented players were identified. When at least one player had a recorded impact, players who were struck tended to have higher rotational acceleration than players in striking positions. When both players had a recorded impact, lighter players and taller players experienced higher mean head accelerations compared with heavier players and shorter players. Understanding the factors influencing HIE during contact events in football may help inform methods to reduce head injury risk.

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Football concussion case series using biomechanical and video analysis

Neurology ◽

10.1212/01.wnl.0000550623.36010.20 ◽

2018 ◽

Vol 91 (23 Supplement 1) ◽

pp. S2.2-S2

Author(s):

Mirellie Kelley ◽

Jillian Urban ◽

Derek Jones ◽

Alexander Powers ◽

Christopher T. Whitlow ◽

...

Keyword(s):

Video Analysis ◽

Case Series ◽

Linear Acceleration ◽

The United States ◽

Head Impact ◽

Rotational Acceleration ◽

Impact Location ◽

Injury Mechanisms ◽

The Mean ◽

Impact Data

Approximately 1.1–1.9 million sport-related concussions among athletes ≤18 years of age occur annually in the United States, but there is limited understanding of the biomechanics and injury mechanisms associated with concussions among lower level football athletes. Therefore, the objective of this study was to combine biomechanical head impact data with video analysis to characterize youth and HS football concussion injury mechanisms. Head impact data were collected from athletes participating on 22 youth and 6 HS football teams between 2012 and 2017. Video was recorded, and head impact data were collected during all practices and games by instrumenting players with the Head Impact Telemetry (HIT) System. For each clinically diagnosed concussion, a video abstraction form was completed, which included questions concerning the context in which the injury occurred. Linear acceleration, rotational acceleration, and impact location were used to characterize the concussive event and each injured athlete's head impact exposure on the day of the concussion. A total of 9 (5 HS and 4 youth) concussions with biomechanics and video of the event were included in this study. The mean [range] linear and rotational acceleration of the concussive impacts were 62.9 [29.3–118.4] g and 3,056.7 [1,046.8–6,954.6] rad/s2, respectively. Concussive impacts were the highest magnitude impacts for 6 players and in the top quartile of impacts for 3 players on the day of injury. Concussions occurred in both practices (N = 4) and games (N = 5). The most common injury contact surface was helmet-to-helmet (N = 5), followed by helmet-to-ground (N = 3) and helmet-to-body (N = 1). All injuries occurred during player-to-player contact scenarios, including tackling (N = 4), blocking (N = 4), and collision with other players (N = 1). The biomechanics and injury mechanisms of concussions varied among athletes in our study; however, concussive impacts were among the highest severity for each player and all concussions occurred as a result of player-to-player contact.

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Can helmet design reduce the risk of concussion in football?

Journal of Neurosurgery ◽

10.3171/2014.1.jns13916 ◽

2014 ◽

Vol 120 (4) ◽

pp. 919-922 ◽

Cited By ~ 71

Author(s):

Steven Rowson ◽

Stefan M. Duma ◽

Richard M. Greenwald ◽

Jonathan G. Beckwith ◽

Jeffrey J. Chu ◽

...

Keyword(s):

Head Impact ◽

Dartmouth College ◽

University Of Minnesota ◽

Head Impacts ◽

University Of Oklahoma ◽

Significant Difference ◽

Rule Changes ◽

Impact Data ◽

Collegiate Football ◽

Helmet Design

Of all sports, football accounts for the highest incidence of concussion in the US due to the large number of athletes participating and the nature of the sport. While there is general agreement that concussion incidence can be reduced through rule changes and teaching proper tackling technique, there remains debate as to whether helmet design may also reduce the incidence of concussion. A retrospective analysis was performed of head impact data collected from 1833 collegiate football players who were instrumented with helmet-mounted accelerometer arrays for games and practices. Data were collected between 2005 and 2010 from 8 collegiate football teams: Virginia Tech, University of North Carolina, University of Oklahoma, Dartmouth College, Brown University, University of Minnesota, Indiana University, and University of Illinois. Concussion rates were compared between players wearing Riddell VSR4 and Riddell Revolution helmets while controlling for the head impact exposure of each player. A total of 1,281,444 head impacts were recorded, from which 64 concussions were diagnosed. The relative risk of sustaining a concussion in a Revolution helmet compared with a VSR4 helmet was 46.1% (95% CI 28.1%–75.8%). When controlling for each player's exposure to head impact, a significant difference was found between concussion rates for players in VSR4 and Revolution helmets (χ2 = 4.68, p = 0.0305). This study illustrates that differences in the ability to reduce concussion risk exist between helmet models in football. Although helmet design may never prevent all concussions from occurring in football, evidence illustrates that it can reduce the incidence of this injury.

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