scholarly journals Can helmet design reduce the risk of concussion in football?

2014 ◽  
Vol 120 (4) ◽  
pp. 919-922 ◽  
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.

scholarly journals Effect of Head Impact Exposures on Changes in Cognitive Testing

2018 ◽  
Vol 6 (3) ◽  
pp. 232596711876103 ◽  
Author(s):  
Eleni Diakogeorgiou ◽  
Theresa L. Miyashita
Keyword(s):  
Reaction Time ◽  
National Collegiate Athletic Association ◽  
Assessment Tool ◽  
Vital Signs ◽  
Head Impact ◽  
Cognitive Testing ◽  
Repeated Impact ◽  
Level Of Evidence ◽  
Head Impacts ◽  
Significant Difference

Background: Gaining a better understanding of head impact exposures may lead to better comprehension of the possible effects of repeated impact exposures not associated with clinical concussion. Purpose: To assess the correlation between head impacts and any differences associated with cognitive testing measurements pre- and postseason. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 34 National Collegiate Athletic Association Division I men’s lacrosse players wore lacrosse helmets instrumented with an accelerometer during the 2014 competitive season and were tested pre- and postseason with the Sport Concussion Assessment Tool (SCAT 3) and Concussion Vital Signs (CVS) computer-based neurocognitive tests. The number of head impacts >20 g and results from the 2 cognitive tests were analyzed for differences and correlation. Results: There was no significant difference between pre- and postseason SCAT 3 scores, although a significant correlation between pre- and postseason cognitive scores on the SCAT 3 and total number of impacts sustained was noted ( r = –0.362, P = .035). Statistically significant improvements on half of the CVS testing components included visual reaction time ( P = .037, d = 0.37), reaction time ( P = .001, d = 0.65), and simple reaction time ( P = .043, d = 0.37), but no correlation with head impacts was noted. Conclusion: This study did not find declines in SCAT 3 or CVS scores over the course of a season among athletes who sustained multiple head impacts but no clinical concussion. Thus, it could not be determined whether there was no cognitive decline among these athletes or whether there may have been subtle declines that could not be measured by the SCAT 3 or CVS.

scholarly journals Subconcussive head impact exposure differences between drill intensities in U.S. high school football

2020 ◽  
Author(s):  
Kyle Kercher ◽  
Jesse A. Steinfeldt ◽  
Jonathan T. Macy ◽  
Keisuke Ejima ◽  
Keisuke Kawata
Keyword(s):  
High School ◽  
Linear Acceleration ◽  
Head Impact ◽  
Football Players ◽  
Impact Frequency ◽  
High School Football ◽  
Head Impacts ◽  
Air Bags ◽  
Frequency Peak ◽  
Impact Data

ABSTRACTPurposeUSA Football established five levels of contact (LOC) to guide the intensity of high school football practices. However, it remains unclear whether head impact exposure differs by LOC. The purpose of this study was to examine head impact frequency and magnitude by LOC in the overall sample and three position groups.MethodsThis longitudinal observational study included 24 high school football players during all practices and games in the 2019 season. Players wore a sensor-installed mouthguard that monitored head impact frequency, peak linear acceleration (PLA), and rotational head acceleration (PRA). Practice/game drills were filmed and categorized into 5 LOCs (air, bags, control, thud, live), and head impact data were assigned into 5 LOCs. Player position was categorized into linemen, hybrid, and skill.ResultsA total of 6016 head impacts were recorded during 5 LOCs throughout the season. In the overall sample, total number of impacts, sum of PLA, and PRA per player increased in an incremental manner (air<bags<control<thud<live), with the most head impacts in live (113.7±17.8 hits/player) and the least head impacts in air (7.7±1.9 hits/player). The linemen and hybrid groups had consistently higher impact exposure than the skill group. Average head impact magnitudes by position group were higher during live drills (PLA (41.0-45.9g) and PRA (3.3-4.6 krad/s2) per head impact), whereas other LOCs had lower magnitudes (PLA (18.2-23.2g) and PRA (1.6-2.3krad/s2) per impact).ConclusionOur data suggest that LOC may influence cumulative head impact exposure in high school football, with players incurring frequent head impacts during live, thud, and control. The data indicate the importance of considering LOCs to refine practice guidelines and policies to minimize head impact burden in high school football athletes.

scholarly journals Frequency and Location of Head Impact Exposures in Individual Collegiate Football Players

2010 ◽  
Vol 45 (6) ◽  
pp. 549-559 ◽  
Author(s):  
Joseph J. Crisco ◽  
Russell Fiore ◽  
Jonathan G. Beckwith ◽  
Jeffrey J. Chu ◽  
Per Gunnar Brolinson ◽  
...  
Keyword(s):  
National Collegiate Athletic Association ◽  
Median Number ◽  
Head Impact ◽  
Clinical Aspects ◽  
Brain Concussion ◽  
Head Impacts ◽  
Session Type ◽  
Subconcussive Impacts ◽  
Player Positions ◽  
Collegiate Football

Abstract Context: Measuring head impact exposure is a critical step toward understanding the mechanism and prevention of sport-related mild traumatic brain (concussion) injury, as well as the possible effects of repeated subconcussive impacts. Objective: To quantify the frequency and location of head impacts that individual players received in 1 season among 3 collegiate teams, between practice and game sessions, and among player positions. Design: Cohort study. Setting: Collegiate football field. Patients or Other Participants: One hundred eighty-eight players from 3 National Collegiate Athletic Association football teams. Intervention(s): Participants wore football helmets instrumented with an accelerometer-based system during the 2007 fall season. Main Outcome Measure(s): The number of head impacts greater than 10g and location of the impacts on the player's helmet were recorded and analyzed for trends and interactions among teams (A, B, or C), session types, and player positions using Kaplan-Meier survival curves. Results: The total number of impacts players received was nonnormally distributed and varied by team, session type, and player position. The maximum number of head impacts for a single player on each team was 1022 (team A), 1412 (team B), and 1444 (team C). The median number of head impacts on each team was 4.8 (team A), 7.5 (team B), and 6.6 (team C) impacts per practice and 12.1 (team A), 14.6 (team B), and 16.3 (team C) impacts per game. Linemen and linebackers had the largest number of impacts per practice and per game. Offensive linemen had a higher percentage of impacts to the front than to the back of the helmet, whereas quarterbacks had a higher percentage to the back than to the front of the helmet. Conclusions: The frequency of head impacts and the location on the helmet where the impacts occur are functions of player position and session type. These data provide a basis for quantifying specific head impact exposure for studies related to understanding the biomechanics and clinical aspects of concussion injury, as well as the possible effects of repeated subconcussive impacts in football.

scholarly journals BIOMECHANIC DATA-DRIVEN BEHAVIOR MODIFICATION TO REDUCE CONCUSSION RISK IN HIGH SCHOOL FOOTBALL ATHLETES

2019 ◽  
Vol 7 (3_suppl) ◽  
pp. 2325967119S0010 ◽  
Author(s):  
Patricia R. Combs ◽  
Cassie B. Ford ◽  
Maryalice Nocera ◽  
Kody R. Campbell ◽  
Stephen W. Marshall ◽  
...  
Keyword(s):  
High School ◽  
High Risk ◽  
Intervention Program ◽  
Head Impact ◽  
Impact Frequency ◽  
High School Football ◽  
Post Intervention ◽  
Head Impacts ◽  
High Magnitude ◽  
Impact Data

Background: Each year, between 1.1 and 1.9 million sports and recreation-related concussions occur annually in US children aged =18 years. Football has a high concussion incidence relative to other youth sports. This is particularly concerning given recent evidence suggesting sport-related concussions are associated with late-life cognitive and psychological dysfunction in former athletes. Unfortunately, there are currently few proven interventions to prevent concussion in football. The purpose of this study was to evaluate a mentored intervention program designed to teach safe play techniques and thereby reduce head impact frequency and severity in high school football players. Methods: In a clustered quasi-experimental study design, the player education intervention program was provided to two out of three teams in year one, two out of four teams in year two, and all four teams in year three. Head impacts were measured using in-helmet accelerometers worn by all players. Head impact data and game video were used to identify “high risk” players on intervention teams to receive individualized mentoring. Players were identified as candidates for intervention based on three criteria: 1) greater than 20% of head impacts sustained to the top of the head, 2) greater than 7% of impacts exceeded 60 g in peak linear acceleration, and 3) player sustained a concussion. High-risk players attended 3 individual or small-group education sessions over 3 weeks with a mentor who analyzed game film to teach safer playing techniques. Intervention effects were evaluated by comparing post-intervention to pre-intervention head impact data. Coach and player satisfaction were assessed to evaluate the program’s acceptability and impact. Results: 220 athletes (143 intervention; 77 control) participated. Of these, 32 (14%) were classified “high risk” with playing techniques amenable to intervention. Overall, 21 (66%) of mentored athletes demonstrated a reduction in top-of-head impacts (considered a high-risk impact zone) and 17 (53%) of mentored athletes demonstrated a reduction in high magnitude (>60 g) hits. On average, the proportion of top-of-head impacts dropped 2.75% in mentored players, and 2.04% in non-mentored players. The proportion of head impacts classified as high-magnitude (>60 g) dropped 1.07% from pre- to post-intervention in mentored players. There was minimal (<1%) change in high magnitude impacts in non-mentored players. In post-season exit surveys, most mentored players “agreed” (n=18, 69%) that his playing behaviors improved because of the study. Most intervention team coaches thought the study was “effective” (n=31, 97%). Conclusions/Significance: Mentoring effects were modest; however, athletes and coaches viewed the program as effective. Behavioral interventions have potential to reduce head impact frequency and severity in football but may require more intensive mentoring than the 3-session model tested in this study. Tables/Figures: [Table: see text][Table: see text]

scholarly journals Magnitude of Head Impact Exposures in Individual Collegiate Football Players

2012 ◽  
Vol 28 (2) ◽  
pp. 174-183 ◽  
Author(s):  
Joseph J. Crisco ◽  
Bethany J. Wilcox ◽  
Jason T. Machan ◽  
Thomas W. McAllister ◽  
Ann-Christine Duhaime ◽  
...  
Keyword(s):  
Cognitive Deficits ◽  
Linear Acceleration ◽  
Head Impact ◽  
Football Players ◽  
Rotational Acceleration ◽  
Head Impacts ◽  
Factors Associated ◽  
Impact Location ◽  
Collegiate Football

The purpose of this study was to quantify the severity of head impacts sustained by individual collegiate football players and to investigate differences between impacts sustained during practice and game sessions, as well as by player position and impact location. Head impacts (N = 184,358) were analyzed for 254 collegiate players at three collegiate institutions. In practice, the 50th and 95th percentile values for individual players were 20.0 g and 49.5 g for peak linear acceleration, 1187 rad/s2 and 3147 rad/s2 for peak rotational acceleration, and 13.4 and 29.9 for HITsp, respectively. Only the 95th percentile HITsp increased significantly in games compared with practices (8.4%, p = .0002). Player position and impact location were the largest factors associated with differences in head impacts. Running backs consistently sustained the greatest impact magnitudes. Peak linear accelerations were greatest for impacts to the top of the helmet, whereas rotational accelerations were greatest for impacts to the front and back. The findings of this study provide essential data for future investigations that aim to establish the correlations between head impact exposure, acute brain injury, and long-term cognitive deficits.

Differences in Head Impact Exposures Between Youth Tackle and Flag Football Games and Practices: Potential Implications for Prevention Strategies

2021 ◽  
pp. 036354652110117
Author(s):  
Kelly Sarmiento ◽  
Dana Waltzman ◽  
Owen Devine ◽  
Xinjian Zhang ◽  
Lara DePadilla ◽  
...  
Keyword(s):  
Large Population ◽  
Head Impact ◽  
Level Of Evidence ◽  
Head Impacts ◽  
Youth Football ◽  
High Magnitude ◽  
Average Impact ◽  
Tackle Football ◽  
Impact Data ◽  
Age Range

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.

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

2019 ◽  
Vol 23 (3) ◽  
pp. 381-389 ◽  
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.

Validation of a Custom Instrumented Retainer Form Factor for Measuring Linear and Angular Head Impact Kinematics

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Logan E. Miller ◽  
Calvin Kuo ◽  
Lyndia C. Wu ◽  
Jillian E. Urban ◽  
David B. Camarillo ◽  
...  
Keyword(s):  
Form Factor ◽  
Degrees Of Freedom ◽  
Rotational Velocity ◽  
Linear Acceleration ◽  
Head Impact ◽  
Contact Sports ◽  
Head Impacts ◽  
Sensing Technology ◽  
The One ◽  
Impact Data

Head impact exposure in popular contact sports is not well understood, especially in the youth population, despite recent advances in impact-sensing technology which has allowed widespread collection of real-time head impact data. Previous studies indicate that a custom-instrumented mouthpiece is a superior method for collecting accurate head acceleration data. The objective of this study was to evaluate the efficacy of mounting a sensor device inside an acrylic retainer form factor to measure six-degrees-of-freedom (6DOF) head kinematic response. This study compares 6DOF mouthpiece kinematics at the head center of gravity (CG) to kinematics measured by an anthropomorphic test device (ATD). This study found that when instrumentation is mounted in the rigid retainer form factor, there is good coupling with the upper dentition and highly accurate kinematic results compared to the ATD. Peak head kinematics were correlated with r2 > 0.98 for both rotational velocity and linear acceleration and r2 = 0.93 for rotational acceleration. These results indicate that a rigid retainer-based form factor is an accurate and promising method of collecting head impact data. This device can be used to study head impacts in helmeted contact sports such as football, hockey, and lacrosse as well as nonhelmeted sports such as soccer and basketball. Understanding the magnitude and frequency of impacts sustained in various sports using an accurate head impact sensor, such as the one presented in this study, will improve our understanding of head impact exposure and sports-related concussion.

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

2018 ◽  
Vol 34 (5) ◽  
pp. 354-360 ◽  
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.

scholarly journals Practice type effects on head impact in collegiate football

2016 ◽  
Vol 124 (2) ◽  
pp. 501-510 ◽  
Author(s):  
Bryson B. Reynolds ◽  
James Patrie ◽  
Erich J. Henry ◽  
Howard P. Goodkin ◽  
Donna K. Broshek ◽  
...  
Keyword(s):  
National Collegiate Athletic Association ◽  
Collegiate Athletes ◽  
Head Impact ◽  
Football Players ◽  
Rotational Acceleration ◽  
Event Type ◽  
Cumulative Impact ◽  
Head Impacts ◽  
Average Impact ◽  
Collegiate Football

OBJECT This study directly compares the number and severity of subconcussive head impacts sustained during helmet-only practices, shell practices, full-pad practices, and competitive games in a National Collegiate Athletic Association (NCAA) Division I-A football team. The goal of the study was to determine whether subconcussive head impact in collegiate athletes varies with practice type, which is currently unregulated by the NCAA. METHODS Over an entire season, a cohort of 20 collegiate football players wore impact-sensing mastoid patches that measured the linear and rotational acceleration of all head impacts during a total of 890 athletic exposures. Data were analyzed to compare the number of head impacts, head impact burden, and average impact severity during helmet-only, shell, and full-pad practices, and games. RESULTS Helmet-only, shell, and full-pad practices and games all significantly differed from each other (p ≤ 0.05) in the mean number of impacts for each event, with the number of impacts being greatest for games, then full-pad practices, then shell practices, and then helmet-only practices. The cumulative distributions for both linear and rotational acceleration differed between all event types (p < 0.01), with the acceleration distribution being similarly greatest for games, then full-pad practices, then shell practices, and then helmet-only practices. For both linear and rotational acceleration, helmet-only practices had a lower average impact severity when compared with other event types (p < 0.001). However, the average impact severity did not differ between any comparisons of shell and full-pad practices, and games. CONCLUSIONS Helmet-only, shell, and full-pad practices, and games result in distinct head impact profiles per event, with each succeeding event type receiving more impacts than the one before. Both the number of head impacts and cumulative impact burden during practice are categorically less than in games. In practice events, the number and cumulative burden of head impacts per event increases with the amount of equipment worn. The average severity of individual impacts is relatively consistent across event types, with the exception of helmet-only practices. The number of hits experienced during each event type is the main driver of event type differences in impact burden per athletic exposure, rather than the average severity of impacts that occur during the event. These findings suggest that regulation of practice equipment could be a fair and effective way to substantially reduce subconcussive head impact in thousands of collegiate football players.

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