scholarly journals The Hammer and the Nail: Biomechanics of Striking and Struck Canadian University Football Players

2021 ◽  
Author(s):  
Jeffrey S. Brooks ◽  
Adam Redgrift ◽  
Allen A. Champagne ◽  
James P. Dickey
Keyword(s):  
College Football ◽  
Head Impact ◽  
Football Players ◽  
Video Footage ◽  
Impact Location ◽  
Rule Changes ◽  
Left And Right ◽  
The Brain

AbstractThis study sought to evaluate head accelerations in both players involved in a football collision. Players on two opposing Canadian university teams were equipped with helmet mounted sensors during one game per season, for two consecutive seasons. A total of 276 collisions between 58 instrumented players were identified via video and cross-referenced with sensor timestamps. Player involvement (striking and struck), impact type (block or tackle), head impact location (front, back, left and right), and play type were recorded from video footage. While struck players did not experience significantly different linear or rotational accelerations between any play types, striking players had the highest linear and rotational head accelerations during kickoff plays (p ≤ .03). Striking players also experienced greater linear and rotational head accelerations than struck players during kickoff plays (p = .001). However, struck players experienced greater linear and rotational accelerations than striking players during kick return plays (p ≤ .008). Other studies have established that the more severe the head impact, the greater risk for injury to the brain. This paper’s results highlight that kickoff play rule changes, as implemented in American college football, would decrease head impact exposure of Canadian university football athletes and make the game safer.

Brain tissue strains vary with head impact location: A possible explanation for increased concussion risk in struck versus striking football players

2019 ◽  
Vol 64 ◽  
pp. 49-57 ◽  
Author(s):  
Benjamin S. Elkin ◽  
Lee F. Gabler ◽  
Matthew B. Panzer ◽  
Gunter P. Siegmund
Keyword(s):  
Brain Tissue ◽  
Head Impact ◽  
Football Players ◽  
Impact Location

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.

Video Analysis of Reported Concussion Events in the National Football League During the 2015-2016 and 2016-2017 Seasons

2018 ◽  
Vol 46 (14) ◽  
pp. 3502-3510 ◽  
Author(s):  
David J. Lessley ◽  
Richard W. Kent ◽  
James R. Funk ◽  
Christopher P. Sherwood ◽  
Joseph M. Cormier ◽  
...  
Keyword(s):  
Injury Prevention ◽  
National Football League ◽  
Sports Injury ◽  
The Body ◽  
American Football ◽  
Video Footage ◽  
Impact Location ◽  
High Prevalence ◽  
Common Activity ◽  
Rule Changes

Background: Concussions in American football remain a high priority of sports injury prevention programs. Detailed video review provides important information on causation, the outcomes of rule changes, and guidance on future injury prevention strategies. Purpose: Documentation of concussions sustained in National Football League games played during the 2015-2016 and 2016-2017 seasons, including consideration of video views unavailable to the public. Study Design: Descriptive epidemiology study. Methods: All reported concussions were reviewed with all available video footage. Standardized terminology and associated definitions were developed to describe and categorize the details of each concussion. Results: Cornerbacks sustained the most concussions, followed by wide receivers, then linebackers and offensive linemen. Half (50%) of concussions occurred during a passing play, 28% during a rushing play, and 21% on a punt or kickoff. Tackling was found to be the most common activity of concussed players, with the side of the helmet the most common helmet impact location. The distribution of helmet impact source—the object that contacted the concussed player’s helmet—differed from studies of earlier seasons, with a higher proportion of helmet-to-body impacts (particularly shoulder) and helmet-to-ground impacts and with a lower proportion of helmet-to-helmet impacts. Helmet-to-ground concussive impacts were notable for the high prevalence of impacts to the back of the helmet and their frequency during passing plays. Conclusion: Concussion causation scenarios in the National Football League have changed over time. Clinical Relevance: The results of this study suggest the need for expanded evaluation of concussion countermeasures beyond solely helmet-to-helmet test systems, including consideration of impacts with the ground and with the body of the opposing player. It also suggests the possibility of position-specific countermeasures as part of an ongoing effort to improve safety.

The Effect of Head Impact Location on Day of Diagnosed Concussion in College Football

2016 ◽  
Vol 48 (7) ◽  
pp. 1239-1243 ◽  
Author(s):  
STEVEN LIAO ◽  
ROBERT C. LYNALL ◽  
JASON P. MIHALIK
Keyword(s):  
College Football ◽  
Head Impact ◽  
Impact Location

scholarly journals Opportunities for Prevention of Concussion and Repetitive Head Impact Exposure in College Football Players

2021 ◽  
Vol 78 (3) ◽  
pp. 346
Author(s):  
Michael A. McCrea ◽  
Alok Shah ◽  
Stefan Duma ◽  
Steven Rowson ◽  
Jaroslaw Harezlak ◽  
...  
Keyword(s):  
College Football ◽  
Head Impact ◽  
Football Players

scholarly journals Cumulative Head Impact Exposure Predicts Later-Life Depression, Apathy, Executive Dysfunction, and Cognitive Impairment in Former High School and College Football Players

2017 ◽  
Vol 34 (2) ◽  
pp. 328-340 ◽  
Author(s):  
Philip H. Montenigro ◽  
Michael L. Alosco ◽  
Brett M. Martin ◽  
Daniel H. Daneshvar ◽  
Jesse Mez ◽  
...  
Keyword(s):  
High School ◽  
Cognitive Impairment ◽  
Executive Dysfunction ◽  
Later Life ◽  
College Football ◽  
Head Impact ◽  
Football Players

The Effect of Visual and Sensory Performance on Head Impact Biomechanics in College Football Players

2013 ◽  
Vol 42 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Jacqueline A. Harpham ◽  
Jason P. Mihalik ◽  
Ashley C. Littleton ◽  
Barnett S. Frank ◽  
Kevin M. Guskiewicz
Keyword(s):  
College Football ◽  
Head Impact ◽  
Football Players ◽  
Head Impact Biomechanics ◽  
Impact Biomechanics

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.

Advantages of Complementary Stereo Images as Viewed with the Low-Temperature Field-Emission SEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1314-1315
Author(s):  
William P. Wergin ◽  
Eric F. Erbe
Keyword(s):  
Fold Increase ◽  
Horizontal Displacement ◽  
Three Dimensions ◽  
Stereo Image ◽  
Stereo Pair ◽  
Sem Micrograph ◽  
Left And Right ◽  
The Common ◽  
The Brain ◽  
Pair Analysis

The eye-brain complex allows those of us with normal vision to perceive and evaluate our surroundings in three-dimensions (3-D). The principle factor that makes this possible is parallax - the horizontal displacement of objects that results from the independent views that the left and right eyes detect and simultaneously transmit to the brain for superimposition. The common SEM micrograph is a 2-D representation of a 3-D specimen. Depriving the brain of the 3-D view can lead to erroneous conclusions about the relative sizes, positions and convergence of structures within a specimen. In addition, Walter has suggested that the stereo image contains information equivalent to a two-fold increase in magnification over that found in a 2-D image. Because of these factors, stereo pair analysis should be routinely employed when studying specimens.Imaging complementary faces of a fractured specimen is a second method by which the topography of a specimen can be more accurately evaluated.

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