scholarly journals Impact on the head during collisions between university American football players - focusing on the number of head impacts and linear head acceleration -

2017 ◽  
Vol 6 (4) ◽  
pp. 241-249 ◽  
Author(s):  
Takashi Fukuda ◽  
Sekiya Koike ◽  
Syumpei Miyakawa ◽  
Hiroto Fujiya ◽  
Yuki Yamamoto
Keyword(s):  
American Football ◽  
Football Players ◽  
Head Acceleration ◽  
Head Impacts

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 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.

Head Impact Exposure in Youth Football: Middle School Ages 12–14 Years

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Ray W. Daniel ◽  
Steven Rowson ◽  
Stefan M. Duma
Keyword(s):  
High School ◽  
Middle School ◽  
Head Impact ◽  
Football Players ◽  
Head Acceleration ◽  
Limited Data ◽  
Head Impacts ◽  
Football Helmet ◽  
Injury Criteria ◽  
Youth Football

The head impact exposure experienced by football players at the college and high school levels has been well documented; however, there are limited data regarding youth football despite its dramatically larger population. The objective of this study was to investigate head impact exposure in middle school football. Impacts were monitored using a commercially available accelerometer array installed inside the helmets of 17 players aged 12–14 years. A total of 4678 impacts were measured, with an average (±standard deviation) of 275 ± 190 impacts per player. The average of impact distributions for each player had a median impact of 22 ± 2 g and 954 ± 122 rad/s2, and a 95th percentile impact of 54 ± 9 g and 2525 ± 450 rad/s2. Similar to the head impact exposure experienced by high school and collegiate players, these data show that middle school football players experience a greater number of head impacts during games than practices. There were no significant differences between median and 95th percentile head acceleration magnitudes experienced during games and practices; however, a larger number of impacts greater than 80 g occurred during games than during practices. Impacts to the front and back of the helmet were most common. Overall, these data are similar to high school and college data that have been collected using similar methods. These data have applications toward youth football helmet design, the development of strategies designed to limit head impact exposure, and child-specific brain injury criteria.

scholarly journals Defining Exposures in Professional Football: Professional American-Style Football Players as an Occupational Cohort

2019 ◽  
Vol 7 (2) ◽  
pp. 232596711982921 ◽  
Author(s):  
Rachel G. Grashow ◽  
Andrea L. Roberts ◽  
Ross Zafonte ◽  
Alvaro Pascual-Leone ◽  
Herman Taylor ◽  
...  
Keyword(s):  
American Football ◽  
Epidemiological Methods ◽  
Football Players ◽  
Professional Football ◽  
Head Impacts ◽  
Adverse Health Outcomes ◽  
Acute Injuries ◽  
Full Complement ◽  
Occupational Cohort

Studies of professional American football players have shown that football-related activities lead to acute injuries and may have long-term adverse health outcomes including osteoarthritis, neurocognitive impairment, and cardiovascular disease. However, the full complement of what constitutes professional football exposure has yet to be effectively articulated. Most likely, professional football exposure encompasses a multifaceted array of experiences including head impacts and joint stresses, long-term pain medication use, dietary restrictions, and strenuous training regimens. To study the health of professional American football players, characterizing the group as an occupational cohort and taking advantage of methods established within the discipline of occupational epidemiology may be beneficial. We conducted a narrative review of existing football research, occupational epidemiological methods papers, and occupational medicine studies. Here we describe the traditional occupational epidemiological approach to assessing exposure in a novel cohort and show how this framework could be implemented in studies of professional football players. In addition, we identify the specific challenges associated with studying an elite athletic occupational group, including the healthy worker effect and other types of selection and information biases, and explore these in the context of existing studies of football-related health. The application of well-established occupational epidemiological methods to professional football players may yield new insights into the effects of playing exposure and may provide opportunities for interventions to reduce harm.

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 Relating on-field youth football head impacts to pneumatic ram laboratory testing procedures

2020 ◽  
pp. 175433712094906
Author(s):  
Eamon T Campolettano ◽  
Steven Rowson
Keyword(s):  
Severity Index ◽  
Football Players ◽  
Head Acceleration ◽  
Head Impacts ◽  
Testing Procedures ◽  
Youth Athletes ◽  
Football Helmet ◽  
Youth Football ◽  
Impact Data ◽  
Athletic Equipment

A youth-specific football helmet testing standard has been proposed to address the physical and biomechanical differences between adult and youth football players. This study sought to relate the proposed youth standard-defined laboratory impacts to on-field head impacts collected from youth football players. Head impact data from 112 youth football players (ages 9–14) were collected through the use of helmet-mounted accelerometer arrays. These head impacts were filtered to only include those that resided in corridors near prescribed National Operating Committee on Standards for Athletic Equipment (NOCSAE) impact locations. Peak linear head acceleration and peak rotational head acceleration magnitudes collected from pneumatic ram impactor tests as specified by the proposed NOCSAE youth standard were compared to the distribution of on-field head impacts. All laboratory impact tests were among the top 10% in terms of magnitude for Severity Index and peak rotational acceleration of matched location head impacts experienced by youth football players. As concussive head impacts are among the most severe impacts experienced on the field, a safety standard geared toward mitigating concussion should assess the most severe on-field head impacts. This proposed testing standard may be refined as more becomes known regarding the biomechanics of concussion among youth athletes.

Chronic Traumatic Encephalopathy: Advocacy and Communicating with the Public

2020 ◽  
Vol 40 (04) ◽  
pp. 461-468
Author(s):  
Madeline Uretsky ◽  
Christopher J. Nowinski
Keyword(s):  
Chronic Traumatic Encephalopathy ◽  
American Football ◽  
Football Players ◽  
Advocacy Groups ◽  
Contact Sport ◽  
Head Impacts ◽  
The Public ◽  
The Past ◽  
Raising Awareness ◽  
Sports Concussions

AbstractOver the past 40 years, advocacy groups have been instrumental in raising awareness for neurodegenerative diseases such as Alzheimer's disease. More recently, advocates have emerged to educate about sports concussions and chronic traumatic encephalopathy (CTE), including the Concussion Legacy Foundation (CLF). CTE is a neurodegenerative disease caused in part by repetitive head impacts (RHI). While the majority of CTE research has focused on studying former American football players, CTE has also been found in military personnel, victims of domestic violence, and contact sport athletes from high school to professional levels of play. Advocates' many goals include creating a culture of brain donation and modifying youth contact sports to decrease RHI. Here, we provide the first review of CTE advocacy, summarize the accomplishments of the CLF, and consider the connections between CTE advocacy, research, and legislation over the last decade.

scholarly journals Age at First Exposure to Repetitive Head Impacts Is Associated with Smaller Thalamic Volumes in Former Professional American Football Players

2018 ◽  
Vol 35 (2) ◽  
pp. 278-285 ◽  
Author(s):  
Vivian Schultz ◽  
Robert A. Stern ◽  
Yorghos Tripodis ◽  
Julie Stamm ◽  
Pawel Wrobel ◽  
...  
Keyword(s):  
American Football ◽  
Football Players ◽  
Head Impacts ◽  
Repetitive Head Impacts

Does tackling form affect head acceleration in youth football players?

2020 ◽  
Vol 234 (3) ◽  
pp. 257-267 ◽  
Author(s):  
Ryan A Gellner ◽  
Eamon T Campolettano ◽  
Steven Rowson
Keyword(s):  
Football Players ◽  
Head Acceleration ◽  
Head Impacts ◽  
Youth Football ◽  
High Magnitude ◽  
Close Range ◽  
Agreement Coefficient ◽  
Reduce Risk ◽  
Effectiveness Of Training ◽  
Age Range

To reduce head impact exposure, a number of youth football organizations have begun teaching tackling technique. This study sought to develop and utilize a set of tackling form grading criteria for both tacklers and ball carriers as well as to relate tackling form to head acceleration outcome. It was hypothesized that players exhibiting better form would experience lower head accelerations in individual tackles. Three teams consisting of 67 players (20, 29, and 18 players per team; age 12.7 ± 0.95, age range 11–14 years, body mass 55.1 ± 16.2 kg) were instrumented with helmet-mounted accelerometer arrays for one season. Videos of close-range tackling drills were used to develop tackling form criteria. Two raters used these criteria to each score 105 impacts. Six of the seven categories were found to have good inter-rater reliability metrics (total percent agreement ≥ 79%, agreement coefficient ≥ 0.65). Bending at both the hips and knees, leading with the shoulder or arm, and initiating contact were found to reduce risk of high-magnitude (>40 g) head impacts in tacklers. Keeping the eyes up and avoiding dropping the head reduced the risk of high-magnitude head impacts in ball carriers. This study shows the potential effectiveness of training both tacklers and ball carriers in proper technique for collisions in youth football to minimize head impacts.

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