scholarly journals High Energy American Football Head Impacts to the Side and Rear Damaging Than to the Front

Neurology ◽  
2019 ◽  
Vol 93 (14 Supplement 1) ◽  
pp. S10.1-S10
Author(s):  
Adam Bartsch ◽  
Edward Benzel ◽  
Sergey Samorezov ◽  
Vincent Miele
Keyword(s):  
High Energy ◽  
Head Impact ◽  
American Football ◽  
Dose Response Relationship ◽  
Positive Events ◽  
Head Impacts ◽  
Injury Threshold ◽  
Impact Location ◽  
Player Game ◽  
Concussive Injury

ObjectiveThe aim of this study was to investigate head impact doses in American football. We analyzed time-synchronized video and data collected during n = 445 player-games of American football resulting in 2851video-verified impacts. Cases where a player sustained impacts and on video was demonstrably witnessed to meet the NFL’s “No-go” criteria were analyzed in-depth.BackgroundIn 2011, after reviewing scalar on-field kinematics data leading concussion clinicians concluded “Recent studies suggest that a concussive injury threshold is elusive, and may, in fact, be irrelevant when predicting the clinical outcome”.1 It is likely that higher fidelity estimates of spatial and temporal impact parameters will clarify the currently unclear impact dose-response relationship.Design/MethodsA total of 2851 video-verified head impacts were identified from 445 player-games. Each event was time-synchronized to video. Any events collected when the athlete was not being impacted in the head were discarded. The remaining true positive events were scrutinized based on published methods to confirm a head impact occurred in the video and the computed motion was physically realistic and matched the video.ResultsWe found a median of 5 video-verified head impacts per player-game, which is far fewer than published studies without video verification.11 For the four players with “No-go” impacts, all were to the side/rear. Coronal plane impact sensitivity has been a hypothesized clinical injury mechanism12 and our results support that hypothesis.ConclusionsWe did not see high PLA/PAA impacts without obvious player “No-go” observations. This finding disagrees with other studies that have reported high PLA/PAA impacts without any demonstrable “No-go” observations13. High energy impacts to the side and rear of the head are more damaging than similar magnitude impacts to the forehead. Armed with this knowledge, clinicians should have more fidelity in their understanding of real-time impact location and severity, and how it relates to athlete concussion risk.

scholarly journals Comparison of video-based and sensor-based head impact exposure

2017 ◽  
Author(s):  
Calvin Kuo ◽  
Lyndia Wu ◽  
Jesus Loza ◽  
Daniel Senif ◽  
Scott C. Anderson ◽  
...  
Keyword(s):  
Angular Position ◽  
Head Impact ◽  
American Football ◽  
Rear Side ◽  
Football Players ◽  
Head Impacts ◽  
Video Assessment ◽  
Impact Location ◽  
Video Observations ◽  
Time Stamps

AbstractPrevious research has sought to quantify head impact exposure using wearable kinematic sensors. However, many sensors suffer from poor accuracy in estimating impact kinematics and count, motivating the need for additional independent impact exposure quantification for comparison. Here, we equipped seven collegiate American football players with instrumented mouthguards, and video recorded practices and games to compare video-based and sensor-based exposure rates and impact location distributions. Over 50 player-hours, we identified 271 helmet contact periods in video, while the instrumented mouthguard sensor recorded 2,032 discrete head impacts. Matching video and mouthguard real-time stamps yielded 193 video-identified helmet contact periods and 217 sensor-recorded impacts. To compare impact locations, we binned matched impacts into frontal, rear, side, oblique, and top locations based on video observations and sensor kinematics. While both video-based and sensor-based methods found similar location distributions, our best method utilizing integrated linear and angular position only correctly predicted 81 of 217 impacts. Finally, based on the activity timeline from video assessment, we also developed a new exposure metric unique to American football quantifying number of cross-verified sensor impacts per player-play. We found significantly higher exposure during games (0.35, 95% CI: 0.29-0.42) than practices (0.20, 95% CI: 0.17-0.23) (p<0.05). In the traditional impacts per player-hour metric, we observed higher exposure during practices (4.7) than games (3.7) due to increased player activity in practices. Thus, our exposure metric accounts for variability in on-field participation. While both video-based and sensor-based exposure datasets have limitations, they can complement one another to provide more confidence in exposure statistics.

Association Between Antemortem FLAIR White Matter Hyperintensities and Neuropathology in Brain Donors Exposed to Repetitive Head Impacts

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000013012
Author(s):  
Madeline Uretsky ◽  
Sylvain Bouix ◽  
Ronald J. Killiany ◽  
Yorghos Tripodis ◽  
Brett Martin ◽  
...  
Keyword(s):  
White Matter ◽  
White Matter Hyperintensities ◽  
Microvascular Disease ◽  
Head Impact ◽  
American Football ◽  
Football Players ◽  
Head Impacts ◽  
Repetitive Head Impacts ◽  
Pathological Correlation ◽  
Daily Function

Background and Objectives:Late neuropathologies of repetitive head impacts from contact sports can include chronic traumatic encephalopathy (CTE) and white matter degeneration. White matter hyperintensities (WMH) on fluid attenuated inversion recovery (FLAIR) MRI scans are often viewed as microvascular disease from vascular risk, but might have unique underlying pathologies and risk factors in the setting of repetitive head impacts. We investigated the neuropathological correlates of antemortem WMH in brain donors exposed to repetitive head impacts. The association between WMH, and repetitive head impact exposure and informant-reported cognitive and daily function were tested.Methods:This imaging-pathological correlation study included symptomatic deceased men exposed to repetitive head impacts. Donors had antemortem FLAIR scans from medical records and were without evidence of CNS neoplasm, large vessel infarcts, hemorrhage, and/or encephalomalacia. WMH were quantified using log-transformed values for total lesion volume (TLV), calculated using the lesion prediction algorithm from the Lesion Segmentation Toolbox. Neuropathological assessments included semi-quantitative ratings of white matter rarefaction, cerebrovascular disease, p-tau severity (CTE stage, dorsolateral frontal cortex), and Aβ. Among football players, years of play was a proxy for repetitive head impact exposure. Retrospective informant-reported cognitive and daily function were assessed using the Cognitive Difficulties Scale (CDS) and Functional Activities Questionnaire (FAQ). Regression models controlled for demographics, diabetes, hypertension, and MRI resolution. Statistical significance was defined as p<0.05.Results:The sample included 75 donors: 67 football players and 8 non-football contact sport athletes and/or military veterans. Dementia was the most common MRI indication (64%). Fifty-three (70.7%) had CTE at autopsy. Log-TLV was associated with white matter rarefaction (OR=2.32, 95% CI=1.03,5.24, p=0.04), arteriolosclerosis (OR=2.38, 95% CI=1.02,5.52, p=0.04), CTE stage (OR=2.58, 95% CI=1.17,5.71, p=0.02), and dorsolateral frontal p-tau severity (OR=3.03, 95% CI=1.32,6.97, p=0.01). There was no association with Aβ. More years of football play was associated with log-TLV (b=0.04, 95% CI=0.01,0.06, p=0.01). Greater log-TLV correlated with higher FAQ (unstandardized beta=4.94, 95% CI=0.42,8.57, p=0.03) and CDS scores (unstandardized beta=15.35, 95% CI=-0.27,30.97, p=0.05).Discussion:WMH might capture long-term white matter pathologies from repetitive head impacts, including those from white matter rarefaction and p-tau, in addition to microvascular disease. Prospective imaging-pathological correlation studies are needed.Classification of Evidence:This study provides Class IV evidence of associations between FLAIR white matter hyperintensities, and neuropathological changes (white matter rarefaction, arteriolosclerosis, p-tau accumulation), years of American football play, and reported cognitive symptoms in symptomatic brain donors exposed to repetitive head impacts.

scholarly journals Biomechanical head impact characteristics during sparring practice sessions in high school taekwondo athletes

2017 ◽  
Vol 19 (6) ◽  
pp. 662-667 ◽  
Author(s):  
David M. O'Sullivan ◽  
Gabriel P. Fife
Keyword(s):  
High School ◽  
Rotational Velocity ◽  
Linear Acceleration ◽  
Head Impact ◽  
Rotational Acceleration ◽  
Head Impacts ◽  
Head Injury Criterion ◽  
Impact Location ◽  
Male High School ◽  
Impact Characteristics

OBJECTIVEThe purpose of this study was to monitor head impact magnitude and characteristics, such as impact location and frequency, at high school taekwondo sparring sessions.METHODSEight male high school taekwondo athletes participated in this study. The head impact characteristics were recorded by X-Patch, a wireless accelerometer and gyroscope, during 6 taekwondo sparring sessions. The outcome measures were the peak linear acceleration (g = 9.81 msec2), peak rotational acceleration, rotational velocity, and Head Injury Criterion.RESULTSA total of 689 impacts occurred over 6 sessions involving the 8 athletes. There was an average of 24 impacts per 100 minutes, and there were significant differences in the frequency of impacts among both the sessions and individual athletes. In order of frequency, the most commonly hit locations were the side (38.2%), back (35.7%), and front (23.8%) of the head.CONCLUSIONSThe data indicate that there is a relatively high number of head impacts experienced by taekwondo athletes during sparring practice. According to the rotational acceleration predicting impact severity published in previous research, 17.1% of the impacts were deemed to be a moderate and 15.5% were deemed to be severe.

scholarly journals Similar head impact acceleration measured using instrumented ear patches in a junior rugby union team during matches in comparison with other sports

2016 ◽  
Vol 18 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Doug A. King ◽  
Patria A. Hume ◽  
Conor Gissane ◽  
Trevor N. Clark
Keyword(s):  
Injury Risk ◽  
Linear Acceleration ◽  
Rugby Union ◽  
Head Impact ◽  
American Football ◽  
Football Players ◽  
Head Impacts ◽  
Impact Acceleration ◽  
The Impact ◽  
Rugby Players

OBJECTIVE Direct impact with the head and the inertial loading of the head have been postulated as major mechanisms of head-related injuries, such as concussion. METHODS This descriptive observational study was conducted to quantify the head impact acceleration characteristics in under-9-year-old junior rugby union players in New Zealand. The impact magnitude, frequency, and location were collected with a wireless head impact sensor that was worn by 14 junior rugby players who participated in 4 matches. RESULTS A total of 721 impacts > 10g were recorded. The median (interquartile range [IQR]) number of impacts per player was 46 (IQR 37–58), resulting in 10 (IQR 4–18) impacts to the head per player per match. The median impact magnitudes recorded were 15g (IQR 12g–21g) for linear acceleration and 2296 rad/sec2 (IQR 1352–4152 rad/sec2) for rotational acceleration. CONCLUSIONS There were 121 impacts (16.8%) above the rotational injury risk limit and 1 (0.1%) impact above the linear injury risk limit. The acceleration magnitude and number of head impacts in junior rugby union players were higher than those previously reported in similar age-group sports participants. The median linear acceleration for the under-9-year-old rugby players were similar to 7- to 8-year-old American football players, but lower than 9- to 12-year-old youth American football players. The median rotational accelerations measured were higher than the median and 95th percentiles in youth, high school, and collegiate American football players.

Characterization of the Biomechanical and Situational Aspects of High Magnitude Subconcussive Impacts in Collegiate Football

Neurology ◽  
2020 ◽  
Vol 95 (20 Supplement 1) ◽  
pp. S1.2-S1
Author(s):  
Kristen Lila Lacelle ◽  
Mario Stampanoni Bassi ◽  
Allen Anthony Champagne ◽  
Nicole Coverdale ◽  
Douglas J. Cook
Keyword(s):  
Linear Acceleration ◽  
Head Impacts ◽  
Video Footage ◽  
Impact Location ◽  
High Magnitude ◽  
Repetitive Exposure ◽  
Individual Player ◽  
Player Game ◽  
Subconcussive Impacts ◽  
The Individual

ObjectiveThe objective of this study was to characterize high magnitude subconcussive impacts in football to identify injurious relationships between player/game-based characteristics and impact magnitude and frequency.BackgroundSubconcussive impacts are asymptomatic head impacts thought to induce alterations in the brain after repetitive exposure. Understanding factors that lead to higher magnitude or frequency of head impacts in football is crucial to develop harm reduction and prevention strategies.Design/MethodsEighty-one male university level football players were equipped with helmet accelerometers to capture linear acceleration (LA), impact frequency and helmet impact location. Impacts with LA = 60 g were included in the analysis. Video footage from 15 games over three seasons was analyzed to characterize aspects of play including play type, position, closing distance, player technique, tackling versus blocking and impact type (helmet-to-helmet/body/ground).ResultsA total of 570 impacts were included in the analysis with a mean LA of 83.44 g ± 23.60. Impacts with a closing distance of = 10 yards resulted in higher LA compared to <10 yards and occurred most frequently in run plays. Wide receivers and defensive backs were most often involved in impacts with a larger closing distance and experienced the highest average LA behind quarterbacks. Helmet-to-body impacts generated significantly higher LA compared to helmet-to-helmet, though helmet-to-helmet occurred more often. Players involved in a tackle sustained significantly higher LAs than those involved in a block. Impacts in which players exhibited poor technique lead to higher LA and occurred more frequently in tackling versus blocking impacts.ConclusionsThe results of this work suggest that rules regarding offensive backfield running starts could be adjusted to decrease risk of impact after a larger closing distance. Behavioral modifications and coaching approaches aimed at improving tackling technique could decrease exposure to threshold impacts at the level of the individual player.

scholarly journals Association of physiological variables with football subconcussive head impacts: Why measure?

2018 ◽  
Author(s):  
Megan E. Huibregtse ◽  
Steven W. Zonner ◽  
Keisuke Ejima ◽  
Zachary W. Bevilacqua ◽  
Sharlene Newman ◽  
...  
Keyword(s):  
High School ◽  
Skeletal Muscle ◽  
Heart Rate ◽  
Muscle Damage ◽  
Physical Exertion ◽  
Head Impact ◽  
American Football ◽  
Physiological Factors ◽  
Head Impacts ◽  
Skeletal Muscle Damage

AbstractSubconcussive head impacts, defined as impacts to the cranium that do not result in clinical symptoms of concussion, are gaining traction as a major public health concern. Researchers begin to suggest subconcussive impact-dependent changes in various neurological measures. However, a contribution of physiological factors such as physical exertion and muscle damage has never been accounted. We conducted a prospective longitudinal study during a high school American football season to examine the association between physiological factors and subconcussive head impact kinematics. Fifteen high-school American football players volunteered in the study. A sensor-installed mouthguard recorded the number of head impacts, peak linear (PLA: g) and peak rotational (PRA: rad/s2) head accelerations from every practice and game. Serum samples were collected at 12 time points (pre-season baseline, five in-season pre-post games, and post-season) and assessed for the creatine kinase skeletal muscle-specific isoenzyme (CK-MM), as a surrogate for skeletal muscle damage. Physical exertion was estimated in the form of excess post-exercise oxygen consumption (EPOC) from heart rate data captured during five games via a wireless heart rate monitor. A total of 9,700 hits, 214,492 g, and 19,885,037 rad/s2 were recorded from 15 players across the study period. Mixed-effect regression models indicated that head impact kinematics (frequency, PLA, and PRA) were significantly and positively associated with CK-MM increase, but not with EPOC. There was a significant and positive association between CK-MM and EPOC. These data suggest that skeletal muscle damage effects should be considered when using outcome measures that may have an interaction with muscle damage, including inflammatory biomarkers and vestibular/balance tests.

scholarly journals Head Impact Exposures Among Youth Tackle and Flag American Football Athletes

2021 ◽  
pp. 194173812199232
Author(s):  
Dana Waltzman ◽  
Kelly Sarmiento ◽  
Owen Devine ◽  
Xinjian Zhang ◽  
Lara DePadilla ◽  
...  
Keyword(s):  
Cohort Study ◽  
Head Impact ◽  
American Football ◽  
Level Of Evidence ◽  
Head Impacts ◽  
High Magnitude ◽  
Increased Risk ◽  
Or Practice ◽  
Observational Prospective Cohort Study ◽  
Tackle Football

Background: Promoted as a safer alternative to tackle football, there has been an increase in flag football participation in recent years. However, examinations of head impact exposure in flag football as compared with tackle football are currently limited. Hypothesis: Tackle football athletes will have a greater number and magnitude of head impacts compared with flag football athletes. Study Design: Cohort study. Level of Evidence: Level 4. Methods: Using mouthguard sensors, this observational, prospective cohort study captured data on the number and magnitude of head impacts among 524 male tackle and flag football athletes (6-14 years old) over the course of a single football season. Estimates of interest based on regression models used Bayesian methods to estimate differences between tackle and flag athletes. Results: There were 186,239 head impacts recorded during the study. Tackle football athletes were 14.67 (95% CI 9.75-21.95) times more likely to sustain a head impact during an athletic exposure (game or practice) compared with flag football athletes. Magnitude of impact for the 50th and 95th percentile was 18.15 g (17.95-18.34) and 52.55 g (51.06-54.09) for a tackle football athlete and 16.84 g (15.57-18.21) and 33.51 g (28.23-39.08) for a flag football athlete, respectively. A tackle football athlete sustained 23.00 (13.59-39.55) times more high-magnitude impacts (≥40 g) per athletic exposure compared with a flag football athlete. Conclusion: This study demonstrates that youth athletes who play tackle football are more likely to experience a greater number of head impacts and are at a markedly increased risk for high-magnitude impacts compared with flag football athletes. Clinical Relevance: These results suggest that flag football has fewer head impact exposures, which potentially minimizes concussion risk, making it a safer alternative for 6- to 14-year-old youth football athletes.

Characterization of Head Impact Exposure in Women’s Collegiate Soccer

2021 ◽  
pp. 1-10
Author(s):  
Tanner M. Filben ◽  
Nicholas S. Pritchard ◽  
Logan E. Miller ◽  
Sarah K. Woods ◽  
Megan E. Hayden ◽  
...  
Keyword(s):  
Brain Injury ◽  
National Collegiate Athletic Association ◽  
Head Impact ◽  
Soccer Players ◽  
Cumulative Exposure ◽  
Head Impacts ◽  
Impact Location ◽  
Impact Rate ◽  
Session Type

Soccer players are regularly exposed to head impacts by intentionally heading the ball. Evidence suggests repetitive subconcussive head impacts may affect the brain, and females may be more vulnerable to brain injury than males. This study aimed to characterize head impact exposure among National Collegiate Athletic Association women’s soccer players using a previously validated mouthpiece-based sensor. Sixteen players were instrumented during 72 practices and 24 games. Head impact rate and rate of risk-weighted cumulative exposure were compared across session type and player position. Head kinematics were compared across session type, impact type, player position, impact location, and ball delivery method. Players experienced a mean (95% confidence interval) head impact rate of 0.468 (0.289 to 0.647) head impacts per hour, and exposure rates varied by session type and player position. Headers accounted for 89% of head impacts and were associated with higher linear accelerations and rotational accelerations than nonheader impacts. Headers in which the ball was delivered by a long kick had greater peak kinematics (all P < .001) than headers in which the ball was delivered by any other method. Results provide increased understanding of head impact frequency and magnitude in women’s collegiate soccer and may help inform efforts to prevent brain injury.

Behavioral Tackling Interventions Decrease Head Impact Frequency in American Football Players: A Critically Appraised Topic

2020 ◽  
pp. 1-7
Author(s):  
Ashley E. Evans ◽  
Madeline Curtis ◽  
Marguerite (Meg) Montjoy ◽  
Erica Beidler
Keyword(s):  
High School ◽  
Injury Prevention ◽  
Head Impact ◽  
American Football ◽  
Football Players ◽  
Clinical Question ◽  
Impact Frequency ◽  
Bottom Line ◽  
Head Impacts ◽  
Different Types

Context: The rate of sport-related concussion diagnosis has significantly increased in recent years, which has created a need for injury prevention initiatives. There have been efforts put forth by researchers and American football organizations to teach athletes how to tackle properly in order to decrease the number of subconcussive head impacts and concussions. Clinical Question: Does the implementation of a behavioral tackling intervention decrease the head impact frequency in American football players? Clinical Bottom Line: There is moderate SORT Level B evidence to support the use of behavioral tackling interventions as a means for reducing head impact frequency in football athletes. All four included studies found a significant reduction in head impacts following a behavioral tackling intervention with study findings ranging from a 26–33% reduction in impact frequency. These findings were consistent in youth, high school, and college football players and for different types of behavioral tackling interventions. Therefore, these results indicate that behavioral tackling interventions have the potential to reduce the number of head impacts sustained by American football players, which may ultimately lead to a reduction in concussion occurrence as well.

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.

Sign in / Sign up

Export Citation Format

Share Document