Association of Increased Serum S100B Levels With High School Football Subconcussive Head Impacts

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.

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Oculomotor Response to Cumulative Subconcussive Head Impacts in US High School Football Players

JAMA Ophthalmology ◽

10.1001/jamaophthalmol.2018.6193 ◽

2019 ◽

Vol 137 (3) ◽

pp. 265 ◽

Cited By ~ 7

Author(s):

Steven W. Zonner ◽

Keisuke Ejima ◽

Ciara C. Fulgar ◽

Carmen N. Charleston ◽

Megan E. Huibregtse ◽

...

Keyword(s):

High School ◽

Football Players ◽

High School Football ◽

Head Impacts ◽

Oculomotor Response

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Head Impacts During High School Football: A Biomechanical Assessment

Yearbook of Sports Medicine ◽

10.1016/s0162-0908(09)79556-x ◽

2010 ◽

Vol 2010 ◽

pp. 30-31

Author(s):

T. Rowland

Keyword(s):

High School ◽

High School Football ◽

Head Impacts ◽

Biomechanical Assessment

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Pupillary changes after clinically asymptomatic high-acceleration head impacts in high school football athletes

Journal of Neurosurgery ◽

10.3171/2019.7.jns191272 ◽

2020 ◽

Vol 133 (6) ◽

pp. 1886-1891 ◽

Cited By ~ 4

Author(s):

Jacob R. Joseph ◽

Jennylee S. Swallow ◽

Kylene Willsey ◽

Andrea A. Almeida ◽

Matthew T. Lorincz ◽

...

Keyword(s):

High School ◽

Repeated Measures ◽

Assessment Tool ◽

Linear Acceleration ◽

Mean Difference ◽

Noninvasive Measurement ◽

Measurement Tool ◽

High School Football ◽

Head Impacts ◽

High Acceleration

OBJECTIVEPrevious studies have shown that clinically asymptomatic high-acceleration head impacts (HHIs) may be associated with neuronal and axonal injury, as measured by advanced imaging and biomarkers. Unfortunately, these methods of measurement are time-consuming, invasive, and costly. A quick noninvasive measurement tool is needed to aid studies of head injury and its biological impact. Quantitative pupillometry is a potential objective, rapid, noninvasive measurement tool that may be used to assess the neurological effects of HHIs. In this study, the authors investigated the effect of HHIs on pupillary metrics, as measured using a pupillometer, in the absence of a diagnosed concussion.METHODSA prospective observational cohort study involving 18 high school football athletes was performed. These athletes were monitored for both the frequency and magnitude of head impacts that they sustained throughout a playing season by using the Head Impact Telemetry System. An HHI was defined as an impact exceeding 95g linear acceleration and 3760 rad/sec2 rotational acceleration. Pupillary assessments were performed at baseline, midseason, after occurrence of an HHI, and at the end of the season by using the NeurOptics NPi-200 pupillometer. The Sport Concussion Assessment Tool, 5th Edition (SCAT5), was also used at each time point. Comparisons of data obtained at the various time points were calculated using a repeated-measures analysis of variance and a t-test.RESULTSSeven athletes sustained HHIs without a related diagnosed concussion. Following these HHIs, the athletes demonstrated decreases in pupil dilation velocity (mean difference 0.139 mm/sec; p = 0.048), percent change in pupil diameter (mean difference 3.643%; p = 0.002), and maximum constriction velocity (mean difference 0.744 mm/sec; p = 0.010), compared to measurements obtained at the athletes’ own midseason evaluations. No significant changes occurred between the SCAT5 subtest scores calculated at midseason and those after a high impact, although the effect sizes (Cohen’s d) on individual components ranged from 0.41 to 0.65.CONCLUSIONSMeasurable changes in pupil response were demonstrated following an HHI. These results suggest that clinically asymptomatic HHIs may affect brain reflex pathways, reflecting a biological injury previously seen when more invasive methods were applied.

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

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967119s00105 ◽

2019 ◽

Vol 7 (3_suppl) ◽

pp. 2325967119S0010 ◽

Cited By ~ 1

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]

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Elevated markers of brain injury as a result of clinically asymptomatic high-acceleration head impacts in high-school football athletes

Journal of Neurosurgery ◽

10.3171/2017.12.jns172386 ◽

2019 ◽

Vol 130 (5) ◽

pp. 1642-1648 ◽

Cited By ~ 10

Author(s):

Jacob R. Joseph ◽

Jennylee S. Swallow ◽

Kylene Willsey ◽

Andrew P. Lapointe ◽

Shokoufeh Khalatbari ◽

...

Keyword(s):

High School ◽

Brain Injury ◽

Linear Acceleration ◽

Blood Sampling ◽

Separate Analysis ◽

Neurocognitive Testing ◽

High School Football ◽

Neurofilament Light ◽

Head Impacts ◽

High Acceleration

OBJECTIVEThis prospective observational cohort study of high-school football athletes was performed to determine if high-acceleration head impacts (HHIs) that do not result in clinically diagnosed concussion still lead to increases in serum levels of biomarkers indicating traumatic brain injury (TBI) in asymptomatic athletes and to determine the longitudinal profile of these biomarkers over the course of the football season.METHODSSixteen varsity high-school football athletes underwent baseline neurocognitive testing and blood sampling for the biomarkers tau, ubiquitin C-terminal hydrolase L1 (UCH-L1), neurofilament light protein (NF-L), glial fibrillary acidic protein (GFAP), and spectrin breakdown products (SBDPs). All athletes wore helmet-based accelerometers to measure and record head impact data during all practices and games. At various time points during the season, 6 of these athletes met the criteria for HHI (linear acceleration > 95g and rotational acceleration > 3760 rad/sec2); in these athletes a second blood sample was drawn at the end of the athletic event during which the HHI occurred. Five athletes who did not meet the criteria for HHI underwent repeat blood sampling following the final game of the season. In a separate analysis, all athletes who did not receive a diagnosis of concussion during the season (n = 12) underwent repeat neurocognitive testing and blood sampling after the end of the season.RESULTSTotal tau levels increased 492.6% ± 109.8% from baseline to postsession values in athletes who received an HHI, compared with 164% ± 35% in athletes who did not receive an HHI (p = 0.03). Similarly, UCH-L1 levels increased 738.2% ± 163.3% in athletes following an HHI, compared with 237.7% ± 71.9% in athletes in whom there was no HHI (p = 0.03). At the end of the season, researchers found that tau levels had increased 0.6 ± 0.2 pg/ml (p = 0.003) and UCH-L1 levels had increased 144.3 ± 56 pg/ml (p = 0.002). No significant elevations in serum NF-L, GFAP, or SBDPs were seen between baseline and end-of–athletic event or end-of-season sampling (for all, p > 0.05).CONCLUSIONSIn this pilot study on asymptomatic football athletes, an HHI was associated with increased markers of neuronal (UCH-L1) and axonal (tau) injury when compared with values in control athletes. These same markers were also increased in nonconcussed athletes following the football season.

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202 Pupillary Changes After Nonconcussive High-Acceleration Head Impacts in High-School Football Athletes

Neurosurgery ◽

10.1093/neuros/nyy303.202 ◽

2018 ◽

Vol 65 (CN_suppl_1) ◽

pp. 116-116

Author(s):

Jacob R Joseph ◽

Jennylee S Swallow ◽

Kylene Willsey ◽

Andrew P Lapointe ◽

Kathryn O’Connor ◽

...

Keyword(s):

High School ◽

High School Football ◽

Head Impacts ◽

High Acceleration

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THE EFFECTS OF INTERNAL JUGULAR VEIN COMPRESSION FOR PRESERVING WHITE MATTER INTEGRITY IN HIGH SCHOOL FOOTBALL PLAYERS COMPARISON OF HIGH VS LOW

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120s00198 ◽

2020 ◽

Vol 8 (4_suppl3) ◽

pp. 2325967120S0019

Author(s):

Kim D. Barber Foss ◽

Jed A. Diekfuss ◽

Weihong Yuan ◽

Jonathan A. Dudley ◽

Christopher A. DiCesare ◽

...

Keyword(s):

High School ◽

White Matter ◽

Internal Jugular Vein ◽

Jugular Vein ◽

Head Impact ◽

Mastoid Process ◽

Control Group ◽

High School Football ◽

Head Impacts ◽

High Level

Background: Repetitive head impacts experienced during competitive sports contribute to neurologic changes over the course of a season. Internal jugular vein compression, by means of an externally worn neck collar device has shown efficacy in mitigating white matter (WM) alterations following repeated head impact exposure. However, its relative effectiveness in high versus low head impact exposures is unknown. Hypothesis/Purpose: The purpose of this study was to investigate the effectiveness of an externally worn neck collar device in limiting WM alterations over a season of high school football in players who receive high and low cumulative head impact exposures over 90 g. Methods: 213 male high-school football athletes were prospectively assigned to two study groups: a control group (non-collar; n=106) and an experimental group who wore the jugular vein compression collar during all practices and games (collar; n=107). MRI data was collected from all participants pre- and post-season. Fractional anisotropy (FA), and mean, axial and radial diffusivity (MD/AD/RD) were calculated to assess WM integrity at both time points. Cumulative head impact exposure was monitored by accelerometers attached to each athlete’s left mastoid process during every exposure. Participants were dichotomized into subgroups based on accumulated exposures to hits over 90 g, which divided the entire cohort into four subgroups, using a cut-off of 40 hits : (1) non-collar group (≥40 hits, n=57); (2) collar group (≥40 hits, n=51); (3) non-collar group (<40 hits, n=49); (4) collar group (<40 hits, n=56). Results: As seen in Table 1, in athletes with ≥40 hits, both the non-collar and collar group showed significant pre- to post- season reductions in MD, AD, and/or RD. The non-collar group with ≥40 hits also showed a significant increase in FA, MD, and AD. RD, FA, and MD changes were greater in the non-collar group compared to the control group with ≥40 hits, while AD changes were greater in the collar group compared to the non-collar group with ≥ 40 hits. The non-collar group with <40 hits presented significant pre- to post-season reductions in MD, AD, and RD that were greater than the collar group with < 40 hits (whom did not show pre-to post-season changes). Discussion & Conclusion: The present results provide support for internal jugular vein compression to protect the brain from both low- and high-level repeated head impact exposure. However, less consistent changes were observed for athletes exposed to repeated, high-level head impacts, warranting further investigation. [Table: see text]

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Head Impacts During High School Football: A Biomechanical Assessment

Journal of Athletic Training ◽

10.4085/1062-6050-44.4.342 ◽

2009 ◽

Vol 44 (4) ◽

pp. 342-349 ◽

Cited By ~ 181

Author(s):

Steven P. Broglio ◽

Jacob J. Sosnoff ◽

SungHoon Shin ◽

Xuming He ◽

Christopher Alcaraz ◽

...

Keyword(s):

High School ◽

Linear Acceleration ◽

Rotational Acceleration ◽

High School Football ◽

Head Impacts ◽

Biomechanical Assessment ◽

Football Team ◽

Impact Biomechanics ◽

Session Type ◽

The Impact

Abstract Little is known about the impact biomechanics sustained by players during interscholastic football.Context: To characterize the location and magnitude of impacts sustained by players during an interscholastic football season.Objective: Observational design.Design: On the field.Setting: High school varsity football team (n = 35; age = 16.85 ± 0.75 years, height = 183.49 ± 5.31 cm, mass = 89.42 ± 12.88 kg).Patients or Other Participants: Biomechanical variables (linear acceleration, rotational acceleration, jerk, force, impulse, and impact duration) related to head impacts were categorized by session type, player position, and helmet impact location.Main Outcome Measure(s): Differences in grouping variables were found for each impact descriptor. Impacts occurred more frequently and with greater intensity during games. Linear acceleration was greatest in defensive linemen and offensive skill players and when the impact occurred at the top of the helmet. The largest rotational acceleration occurred in defensive linemen and with impacts to the front of the helmet. Impacts with the highest-magnitude jerk, force, and impulse and shortest duration occurred in the offensive skill, defensive line, offensive line, and defensive skill players, respectively. Top-of-the-helmet impacts yielded the greatest magnitude for the same variables.Results: We are the first to provide a biomechanical characterization of head impacts in an interscholastic football team across a season of play. The intensity of game play manifested with more frequent and intense impacts. The highest-magnitude variables were distributed across all player groups, but impacts to the top of the helmet yielded the highest values. These high school football athletes appeared to sustain greater accelerations after impact than their older counterparts did. How this finding relates to concussion occurrence has yet to be elucidated.Conclusions:

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