scholarly journals Quantitative and qualitative analysis of head and body impacts in American 7v7 non-tackle football

2020 ◽  
Vol 6 (1) ◽  
pp. e000638 ◽  
Author(s):  
Ron Jadischke ◽  
Jessica Zendler ◽  
Erik Lovis ◽  
Andrew Elliott ◽  
Grant C Goulet
Keyword(s):  
Image Matching ◽  
American Football ◽  
Young Athletes ◽  
Head Protection ◽  
Certification Standards ◽  
Tackle Football ◽  
Type Frequency ◽  
Ground Impact ◽  
D Model ◽  
Lower Contact

ObjectivesNon-tackle American football is growing in popularity, and it has been proposed as a safer alternative for young athletes interested in American football. Little is known about the nature of head contact in the sport, which is necessary to inform the extent to which protective headgear is warranted. The objective of this study was to identify the location, types and frequency of head and body contacts in competitive 7v7 non-tackle American football.MethodsVideo analysis was used to document the type, frequency and mechanism of contacts across a series of under 12, under 14 and high school non-tackle tournament games. A subset of impacts was quantitatively analysed via 3-D model-based image matching to calculate the preimpact and postimpact speed of players’ heads and the change in resultant translational and rotational velocities.ResultsThe incidence rate of head contact was found to be low (3.5 contacts per 1000 athlete-plays). Seventy-five per cent of head contacts were caused by a head-to-ground impact. No head-to-head contacts were identified. Most contacts occurred to the rear upper (occiput) or side upper (temporal/parietal) regions. Head-to-ground impact was associated with a maximum preimpact velocity of 5.9±2.2 m/s and a change in velocity of 3.0±1.1 m/s.ConclusionNon-tackle football appears to represent a lower contact alternative to tackle football. The distribution of head impact locations, mechanisms and energies found in the present study is different than what has been previously reported for tackle football. The existing tackle football standards are not appropriate to be applied to the sport of non-tackle football, and sport-specific head protection and headgear certification standards must be determined.

Association between community socioeconomic characteristics and access to youth flag football

2018 ◽  
Vol 25 (4) ◽  
pp. 278-282 ◽  
Author(s):  
Emily Kroshus ◽  
Aly J Sonnen ◽  
Sara PD Chrisman ◽  
Frederick P Rivara
Keyword(s):  
College Education ◽  
Brain Trauma ◽  
American Football ◽  
Regression Analyses ◽  
Multivariate Logistic Regression ◽  
Community Based ◽  
American Academy Of Pediatrics ◽  
Tackle Football ◽  
Voluntary Community ◽  
Lower Contact

BackgroundThe American Academy of Pediatrics has recommended that opportunities for non-tackling American football (e.g., flag football) be expanded, given concerns about the risks of brain trauma from tackle football. This study tested the hypothesis that flag football would be more accessible in communities characterised by higher socioeconomic status residents.MethodsIn July 2017, the locations of community-based organisations offering youth flag and tackle football for youth between the ages of 6 and 13 in two US states (Georgia and Washington) were aggregated (n=440). Organisations were coded in terms of the availability of tackle and/or flag football teams for youth at each year of age between 6 and 13. Multivariate logistic regression analyses were used to assess the odds of a community-based football organisation offering flag football, by community socioeconomic and demographic characteristics.ResultsIn both states, communities with more educated residents were more likely to offer flag football for youth aged 6–12. For example, among 6 year-olds every 10% increase in the number of adult residents with a college education was associated with 1.51 times the odds of flag football availability (95% CI 1.22 to 1.86, P<0.001).ConclusionThese results suggest that youth living in communities characterised by low educational attainment are less likely than other youth to have the option of a lower contact alternative to tackle football. Relying on voluntary community-level adoption of lower contact alternatives to tackle football may result in inequitable access to such sport options. This may contribute to an inequitable burden of brain trauma from youth sport.

A Hit on American Football: A Case Study of Bottom-up Framing Through Op-Ed Readers’ Comments

2016 ◽  
Vol 9 (4) ◽  
pp. 499-518 ◽  
Author(s):  
Travis R. Bell ◽  
Jimmy Sanderson
Keyword(s):  
New York ◽  
Cultural Values ◽  
Sport Participation ◽  
National Football League ◽  
Health And Safety ◽  
New York Times ◽  
Online News ◽  
American Football ◽  
Bottom Up ◽  
Tackle Football

In December 2015, the movie Concussion was released. The film portrayed the story of Dr Bennet Omalu, who is credited with discovering chromic traumatic encephalopathy in the brains of deceased National Football League players. Before the release, on December 7, 2015, Omalu penned an op-ed in The New York Times in which he opined that children should not play tackle football. This research explores 114 reader comments on Omalu’s op-ed through the lens of Nisbet’s bottom-up framing. Using a mixed-methods approach, the results indicated that participants framed the issue through health and safety, American cultural values, parenting liability, and skepticism. Linguistic analysis revealed that comments contained a negative tone, with women’s comments being more negative than men’s. The analysis suggests that online news forums function as spaces where public deliberation around the viability of children playing tackle football occurs and illustrates the tensions around risk, sport participation, and health and safety that confront parents as they grapple with the decision to let their children play tackle football

No Game for Boys to Play

2019 ◽  
Author(s):  
Kathleen Bachynski
Keyword(s):  
United States ◽  
High School ◽  
Twentieth Century ◽  
Chronic Disease ◽  
Child Health ◽  
Young Athletes ◽  
High School Football ◽  
Broken Bones ◽  
History Of ◽  
Tackle Football

From the untimely deaths of young athletes to chronic disease among retired players, roiling debates over tackle football have profound implications for more than one million American boys—some as young as five years old—who play the sport every year. In this book, Kathleen Bachynski offers the first history of youth tackle football and debates over its safety. In the postwar United States, high school football was celebrated as a “moral” sport for young boys, one that promised and celebrated the creation of the honorable male citizen. Even so, Bachynski shows that throughout the twentieth century, coaches, sports equipment manufacturers, and even doctors were more concerned with “saving the game” than young boys’ safety—even though injuries ranged from concussions and broken bones to paralysis and death. By exploring sport, masculinity, and citizenship, Bachynski uncovers the cultural priorities other than child health that made a collision sport the most popular high school game for American boys. These deep-rooted beliefs continue to shape the safety debate and the possible future of youth tackle football.

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.

scholarly journals Return to play with hypertrophic cardiomyopathy: are we moving too fast? A critical review

2021 ◽  
pp. bjsports-2020-102921
Author(s):  
Jonathan A Drezner ◽  
Aneil Malhotra ◽  
Jordan M Prutkin ◽  
Michael Papadakis ◽  
Kimberly G Harmon ◽  
...  
Keyword(s):  
Decision Making ◽  
Hypertrophic Cardiomyopathy ◽  
Shared Decision Making ◽  
Sports Participation ◽  
American Football ◽  
Return To Play ◽  
Medical Decision ◽  
Competitive Sports ◽  
Shared Decision ◽  
Young Athletes

The diagnosis of a potentially lethal cardiovascular disease in a young athlete presents a complex dilemma regarding athlete safety, patient autonomy, team or institutional risk tolerance and medical decision-making. Consensus cardiology recommendations previously supported the ‘blanket’ disqualification of athletes with hypertrophic cardiomyopathy (HCM) from competitive sport. More recently, epidemiological studies examining the relative contribution of HCM as a cause of sudden cardiac death (SCD) in young athletes and reports from small cohorts of older athletes with HCM that continue to exercise have fueled debate whether it is safe to play with HCM. Shared decision-making is endorsed within the sports cardiology community in which athletes can make an informed decision about treatment options and potentially elect to continue competitive sports participation. This review critically examines the available evidence relevant to sports eligibility decisions in young athletes diagnosed with HCM. Histopathologically, HCM presents an unstable myocardial substrate that is vulnerable to ventricular tachyarrhythmias during exercise. Studies support that young age and intense competitive sports are risk factors for SCD in patients with HCM. We provide an estimate of annual mortality based on our understanding of disease prevalence and the incidence of HCM-related SCD in different athlete populations. Adolescent and young adult male athletes and athletes participating in a higher risk sport such as basketball, soccer and American football exhibit a greater risk. This review explores the potential harms and benefits of sports disqualification in athletes with HCM and details the challenges and limitations of shared decision-making when all parties may not agree.

scholarly journals Risk of incidental and recurrent injuries among young athletes of selected team games

2020 ◽  
Vol 3 (3) ◽  
pp. 91-102
Author(s):  
Dawid Koźlenia ◽  
Jarosław Domaradzki
Keyword(s):  
Sports Injuries ◽  
Sports Injury ◽  
American Football ◽  
Football Players ◽  
Training Volume ◽  
Young Athletes ◽  
Training Experience ◽  
Team Games ◽  
Proper Training ◽  
Recurrent Injuries

Purpose: The research aimed to assess the risk of incidental and recurrent injuries in young athletes according to the training experience, training weekly volume, and morphological features.Methods: One hundred and twenty-five male athletes were included in the study (22 American football players, 30 football players, 49 handball players, and 24 volleyball players). Injures data were collected with the questionnaire.Results: Most of the young players were injured. The basic risk factors of incidental injuries are the length of the training experience. In the case of recurrent injuries, it is also a training internship and a weekly training volume. The risk of incidental injury increases with 30% every year. In the case of recurrent injuries, the risks associated with each year of training by 28%, and 26% with an increase in training volume. The morphological did not increase injury risk.Conclusion: With the training experience, training volume, the risk of sports injury increases. Long-term activities are required in the training process with proper training loads, methods of preventing sports injuries, and regeneration techniques for the protection of young athletes from injuries.

scholarly journals American Football: Watch Your Head!

2021 ◽  
Vol 9 ◽  
Author(s):  
Kelly Sarmiento ◽  
Dana Waltzman
Keyword(s):  
Young People ◽  
Brain Injuries ◽  
American Football ◽  
Football Players ◽  
Head Impacts ◽  
Or Practice ◽  
Tackle Football

Head impacts in American football may lead to brain injuries called concussions. To study head impacts in young people who play American football, we collected data using sensors in mouthguards worn by young American football players. The sensors counted the number of hits and bumps to the head (head impacts) that players of American tackle and flag football got during the football season. We found that tackle football players had about 15 times more head impacts during a game or practice than flag football players had, and 23 times more hard head impacts. Learning more about head impacts in young American football players can help scientists find ways to lower the chances of concussions and other injuries. That way, kids can enjoy the benefits of sports while keeping their brains safe.

Microstructural Characterization of Au-Ge-Ni based ohmic contacts to GaAs/AlGaAs modfet device

1987 ◽  
Vol 45 ◽  
pp. 326-327
Author(s):  
A.K. Rai ◽  
A.K. Petford-Long ◽  
A. Ezis ◽  
D.W. Langer
Keyword(s):  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Microstructural Characterization ◽  
Almost Everywhere ◽  
Spacer Layer ◽  
Good Contact ◽  
The Relationship ◽  
Lower Contact

Considerable amount of work has been done in studying the relationship between the contact resistance and the microstructure of the Au-Ge-Ni based ohmic contacts to n-GaAs. It has been found that the lower contact resistivity is due to the presence of Ge rich and Au free regions (good contact area) in contact with GaAs. Thus in order to obtain an ohmic contact with lower contact resistance one should obtain a uniformly alloyed region of good contact areas almost everywhere. This can possibly be accomplished by utilizing various alloying schemes. In this work microstructural characterization, employing TEM techniques, of the sequentially deposited Au-Ge-Ni based ohmic contact to the MODFET device is presented.The substrate used in the present work consists of 1 μm thick buffer layer of GaAs grown on a semi-insulating GaAs substrate followed by a 25 Å spacer layer of undoped AlGaAs.

Compositional Analysis of III-V Interface Lattice Images

1980 ◽  
Vol 38 ◽  
pp. 318-319
Author(s):  
A. Olsen ◽  
J.C.H. Spence ◽  
P. Petroff
Keyword(s):  
Crystal Structure ◽  
Image Matching ◽  
Compositional Analysis ◽  
Depth Of Field ◽  
Limit Set ◽  
High Contrast ◽  
Resolution Limit ◽  
Fourier Image ◽  
Lattice Images ◽  
True Structure

Since the point resolution of the JEOL 200CX electron microscope is up = 2.6Å it is not possible to obtain a true structure image of any of the III-V or elemental semiconductors with this machine. Since the information resolution limit set by electronic instability (1) u0 = (2/πλΔ)½ = 1.4Å for Δ = 50Å, it is however possible to obtain, by choice of focus and thickness, clear lattice images both resembling (see figure 2(b)), and not resembling, the true crystal structure (see (2) for an example of a Fourier image which is structurally incorrect). The crucial difficulty in using the information between Up and u0 is the fractional accuracy with which Af and Cs must be determined, and these accuracies Δff/4Δf = (2λu2Δf)-1 and ΔCS/CS = (λ3u4Cs)-1 (for a π/4 phase change, Δff the Fourier image period) are strongly dependent on spatial frequency u. Note that ΔCs(up)/Cs ≈ 10%, independent of CS and λ. Note also that the number n of identical high contrast spurious Fourier images within the depth of field Δz = (αu)-1 (α beam divergence) decreases with increasing high voltage, since n = 2Δz/Δff = θ/α = λu/α (θ the scattering angle). Thus image matching becomes easier in semiconductors at higher voltage because there are fewer high contrast identical images in any focal series.

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