scholarly journals Game-Related Impacts in High School Boys’ Lacrosse

2019 ◽  
Vol 7 (4) ◽  
pp. 232596711983558 ◽  
Author(s):  
Shane V. Caswell ◽  
Patricia Kelshaw ◽  
Andrew E. Lincoln ◽  
Lisa Hepburn ◽  
Reginald Dunn ◽  
...  
Keyword(s):  
High School ◽  
Rotational Velocity ◽  
Linear Acceleration ◽  
The United States ◽  
Head Impact ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Head Impacts ◽  
Direct Head ◽  
The Impact

Background: The rate of concussions in boys’ lacrosse is reported to be the third highest among high school sports in the United States, but no studies have described game-related impacts among boys’ lacrosse players. Purpose: To characterize verified game-related impacts, both overall and those directly to the head, in boys’ varsity high school lacrosse. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 77 male participants (mean age, 16.6 ± 1.2 years; mean height, 1.77 ± 0.05 m; mean weight, 73.4 ± 12.2 kg) were instrumented with sensors and were videotaped during 39 games. All verified game-related impacts ≥20 g were summarized in terms of frequency, peak linear acceleration (PLA), and peak rotational velocity (PRV). Descriptive statistics and impact rates per player-game (PG) with corresponding 95% CIs were calculated. Results: Overall, 1100 verified game-related impacts were recorded (PLA: median, 33.5 g [interquartile range (IQR), 25.7-51.2]; PRV: median, 1135.5 deg/s [IQR, 790.0-1613.8]) during 795 PGs. The rate for all verified game-related impacts was 1.38 impacts per PG (95% CI, 1.30-1.47). Of these, 680 (61.8%) impacts (PLA: median, 35.9 g [IQR, 26.7-55.5]; PRV: 1170.5 deg/s [IQR, 803.2-1672.8]) were directly to the head (impact rate, 0.86 impacts/PG [95% CI, 0.79-0.92]). Overall, midfielders (n = 514; 46.7%) sustained the most impacts, followed by attackers (n = 332; 30.2%), defenders (n = 233; 21.2%), and goalies (n = 21; 1.9%). The most common mechanisms for overall impacts and direct head impacts were contact with player (overall: n = 706 [64.2%]; head: n = 397 [58.4%]) and stick (overall: n = 303 [27.5%]; head: n = 239 [35.1%]), followed by ground (overall: n = 73 [6.6%]; head: n = 26 [3.8%]) and ball (overall: n = 15 [1.4%]; head: n = 15 [2.2%]). Direct head impacts were associated with a helmet-to-helmet collision 31.2% of the time, and they were frequently (53.7%) sustained by the players delivering the impact. Nearly half (48.8%) of players delivering contact used their helmets to initiate contact that resulted in a helmet-to-helmet impact. Players receiving a head impact from player contact were most often unprepared (75.9%) for the collision. Conclusion: The helmet is commonly used to initiate contact in boys’ high school lacrosse, often targeting defenseless opponents. Interventions to reduce head impacts should address rules and coaching messages to discourage intentional use of the helmet and encourage protection of defenseless opponents.

scholarly journals Timing and Reasons Behind Single-Sport Specialization in Soccer: A Survey of 64 Major League Soccer Athletes

2020 ◽  
Vol 12 (4) ◽  
pp. 355-360
Author(s):  
Derrick M. Knapik ◽  
Katherine H. Rizzone ◽  
James E. Voos
Keyword(s):  
High School ◽  
The United States ◽  
Injury Incidence ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Advanced Level ◽  
School Location ◽  
Major League Soccer ◽  
Major League ◽  
The Impact

Background: Single-sport specialization at the exclusion of other sports has become increasingly popular in youth sporting culture. The purpose of this study was to survey Major League Soccer (MLS) athletes to examine factors influencing the timing of single-sport specialization in soccer. Hypothesis: The majority of surveyed athletes will have participated in multiple sports prior to specialization and specialized primarily as a result of a coach’s recommendation, with no significant impact on specialization timing stemming from birth or high school location, obtaining a collegiate scholarship, MLS experience, or position. Study Design: Cross-sectional study. Level of Evidence: Level 4. Methods: Anonymous surveys were distributed to 3 MLS organizations and completed by MLS athletes during preseason physicals. Surveys evaluated the age and reason(s) behind an athlete’s decision to specialize in soccer, birth location, geographic high school location for US-born athletes, participation in a developmental league, college scholarship, years in the MLS, and position played. Results: Approximately 74% (64/86) of athletes returned completed surveys. Athletes reported beginning soccer at a mean age of 5.1 ± 2.1 years and specializing at age 12.6 ± 4.3 years. Athletes who participated in no other sports prior to specialization ( P < 0.001), athletes reporting soccer to be their first sport played at an advanced level ( P < 0.001), and athletes receiving a college scholarship ( P = 0.02) specialized at a significantly younger age. Internationally born athletes specialized at significantly younger ages when compared with US-born athletes ( P < 0.001). Conclusion: The majority of athletes participated in multiple sports prior to specialization and eventually specialized to focus exclusively on soccer. The timing of sport specialization in professional MLS athletes was not associated with multisport participation prior to specialization, playing soccer at an advanced level prior to other sports, receiving a college scholarship, or being born outside the United States. Clinical Relevance: Timing of sport specialization is associated with multiple factors prior to athlete promotion to the MLS that warrant further investigation to better understand the impact of specialization on injury incidence, performance, and career length.

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 Do American Youth Football Players Intentionally Use Their Heads for High-Magnitude Impacts?

2019 ◽  
Vol 47 (14) ◽  
pp. 3498-3504 ◽  
Author(s):  
Jaclyn Alois ◽  
Srinidhi Bellamkonda ◽  
Eamon T. Campolettano ◽  
Ryan A. Gellner ◽  
Amaris Genemaras ◽  
...  
Keyword(s):  
Head Injuries ◽  
Cross Sectional Study ◽  
Head Impact ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Impact Mechanism ◽  
Head Impacts ◽  
Youth Football ◽  
High Magnitude ◽  
The Impact

Background: Concern for head injuries is widespread and has been reported by the media to be the number one cause of decreased participation in football among the American youth population. Identifying player mechanisms associated with intentional, or purposeful, head impacts should provide critical data for rule modifications, educational programs, and equipment design. Purpose: To investigate the frequency of intentional and unintentional head impacts and to examine the player mechanisms associated with intentional high-magnitude head impacts by comparing the impact mechanism distributions among session type, player position, and ball possession. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Head impact sensors and video footage of 68 players were used to analyze and classify 1319 high-magnitude impacts recorded over 1 season of youth football. Results: In total, 80% of the high-magnitude head impacts were classified as being caused by intentional use of the head. Head-to-head impact was the primary impact mechanism (n = 868; 82.7%) within the 1050 intentional high-magnitude impacts, with classifiable mechanisms, followed by head-to-body (n = 139; 13.2%), head-to-ground (n = 34; 3.2%), and head-to-equipment (n = 9; 0.9%). Head-to-head impacts also accounted for a greater proportion of impacts during practices (n = 625; 88.9%) than games, for linemen (n = 585; 90.3%) than perimeters and backs, and for ball carriers (n = 72; 79.1%) than tacklers. Conclusion: Overall, the majority of high-magnitude head impacts were intentional and resulted from head-to-head contact. The proportion of head-to-head contact was significantly higher for practices than games, linemen than backs and perimeter players, and ball carriers than tacklers.

Video Analysis Verification of Head Impact Events Measured by Wearable Sensors

2017 ◽  
Vol 45 (10) ◽  
pp. 2379-2387 ◽  
Author(s):  
Nelson Cortes ◽  
Andrew E. Lincoln ◽  
Gregory D. Myer ◽  
Lisa Hepburn ◽  
Michael Higgins ◽  
...  
Keyword(s):  
Video Analysis ◽  
Rotational Velocity ◽  
Wearable Sensors ◽  
Linear Acceleration ◽  
Current Data ◽  
Head Impact ◽  
Accelerometer Data ◽  
Level Of Evidence ◽  
Head Impacts ◽  
Impact Events

Background: Wearable sensors are increasingly used to quantify the frequency and magnitude of head impact events in multiple sports. There is a paucity of evidence that verifies head impact events recorded by wearable sensors. Purpose: To utilize video analysis to verify head impact events recorded by wearable sensors and describe the respective frequency and magnitude. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Thirty male (mean age, 16.6 ± 1.2 years; mean height, 1.77 ± 0.06 m; mean weight, 73.4 ± 12.2 kg) and 35 female (mean age, 16.2 ± 1.3 years; mean height, 1.66 ± 0.05 m; mean weight, 61.2 ± 6.4 kg) players volunteered to participate in this study during the 2014 and 2015 lacrosse seasons. Participants were instrumented with GForceTracker (GFT; boys) and X-Patch sensors (girls). Simultaneous game video was recorded by a trained videographer using a single camera located at the highest midfield location. One-third of the field was framed and panned to follow the ball during games. Videographic and accelerometer data were time synchronized. Head impact counts were compared with video recordings and were deemed valid if (1) the linear acceleration was ≥20 g, (2) the player was identified on the field, (3) the player was in camera view, and (4) the head impact mechanism could be clearly identified. Descriptive statistics of peak linear acceleration (PLA) and peak rotational velocity (PRV) for all verified head impacts ≥20 g were calculated. Results: For the boys, a total recorded 1063 impacts (2014: n = 545; 2015: n = 518) were logged by the GFT between game start and end times (mean PLA, 46 ± 31 g; mean PRV, 1093 ± 661 deg/s) during 368 player-games. Of these impacts, 690 were verified via video analysis (65%; mean PLA, 48 ± 34 g; mean PRV, 1242 ± 617 deg/s). The X-Patch sensors, worn by the girls, recorded a total 180 impacts during the course of the games, and 58 (2014: n = 33; 2015: n = 25) were verified via video analysis (32%; mean PLA, 39 ± 21 g; mean PRV, 1664 ± 619 rad/s). Conclusion: The current data indicate that existing wearable sensor technologies may substantially overestimate head impact events. Further, while the wearable sensors always estimated a head impact location, only 48% of the impacts were a result of direct contact to the head as characterized on video. Using wearable sensors and video to verify head impacts may decrease the inclusion of false-positive impacts during game activity in the analysis.

scholarly journals Differences in the Mechanism of Head Impacts Measured Between Men’s and Women’s Intercollegiate Lacrosse Athletes

2018 ◽  
Vol 6 (11) ◽  
pp. 232596711880767 ◽  
Author(s):  
Rachel K. Le ◽  
Tabitha D. Saunders ◽  
Katherine M. Breedlove ◽  
Debbie A. Bradney ◽  
Jill M. Lucas ◽  
...  
Keyword(s):  
The United States ◽  
Ncaa Division Iii ◽  
Incidence Rates ◽  
Head Impact ◽  
Common Mechanism ◽  
Division Iii ◽  
Level Of Evidence ◽  
Impact Mechanism ◽  
Head Impacts ◽  
The Impact

Background: Lacrosse is a rapidly growing sport in the United States. Comparing the magnitude and frequency of head impact mechanisms between sexes will provide data for injury prevention techniques and risk reduction of head injuries. Purpose: To compare sex-specific differences in the magnitude and frequency of head impact mechanisms in National Collegiate Athletic Association (NCAA) Division III intercollegiate lacrosse athletes. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 31 NCAA Division III intercollegiate lacrosse athletes (16 men [mean age, 21 ± 1 years; mean height, 179.70 ± 5.82 cm; mean weight, 80.71 ± 6.33 kg] and 15 women [mean age, 20 ± 1 years; mean height, 165.43 ± 5.25 cm; mean weight, 64.08 ± 7.59 kg]) voluntarily participated in this study. Participants wore xPatch sensors at every event during the 2015 spring season. Sensors recorded the magnitude, frequency, and location of head impacts over 10 g. Linear ( g) and rotational (deg/s2) acceleration determined impact magnitudes. We calculated incidence rates (IRs; per 1000 athlete-exposures [AEs]) and incidence rate ratios (IRRs) with 95% CIs to determine frequency differences. Film footage from each event was synchronized with the time of each head impact for verification and mechanism coding. Sex and impact mechanism served as the independent variables. Results: A significant interaction was found between impact mechanism and sex ( P < .001) and main effects for impact mechanism ( P < .001) and sex ( P < .001). The most common mechanism in men’s lacrosse was head to body (IR, 970.55/1000 AEs [95% CI, 266.14-331.98]), and in women’s lacrosse, stick to head (IR, 289.87/1000 AEs [95% CI, 124.32-184.55]) was most common. Only 9 of 419 impermissible head impacts in men’s lacrosse games were classed as penalties (2%); 7 of 25 impermissible head impacts in women’s lacrosse games were called as penalties (28%). Conclusion: The impact mechanisms of head to body in men’s lacrosse and stick to head in women’s lacrosse are penalties but occur frequently, suggesting that a focus on stressing rule enforcement is warranted. Because mechanism and sex affect the magnitude of head impacts, proper offensive and defensive techniques against opponents should be encouraged to reduce head impacts.

Head Impact Biomechanics in Youth Flag Football: A Prospective Cohort Study

2021 ◽  
pp. 036354652110266
Author(s):  
Landon B. Lempke ◽  
Rachel S. Johnson ◽  
Rachel K. Le ◽  
Melissa N. Anderson ◽  
Julianne D. Schmidt ◽  
...  
Keyword(s):  
Mixed Model ◽  
Linear Acceleration ◽  
Cross Sectional Study ◽  
Head Impact ◽  
Rotational Acceleration ◽  
Event Type ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Head Impact Biomechanics ◽  
Impact Biomechanics

Background: Youth flag football participation has rapidly grown and is a potentially safer alternative to tackle football. However, limited research has quantitatively assessed youth flag football head impact biomechanics. Purpose: To describe head impact biomechanics outcomes in youth flag football and explore factors associated with head impact magnitudes. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We monitored 52 player-seasons among 48 male flag football players (mean ± SD; age, 9.4 ± 1.1 years; height, 138.6 ± 9.5 cm; mass, 34.7 ± 9.2 kg) across 3 seasons using head impact sensors during practices and games. Sensors recorded head impact frequencies, peak linear ( g) and rotational (rad/s2) acceleration, and estimated impact location. Impact rates (IRs) were calculated as 1 impact per 10 player-exposures; IR ratios (IRRs) were used to compare season, event type, and age group IRs; and 95% CIs were calculated for IRs and IRRs. Weekly and seasonal cumulative head impact frequencies and magnitudes were calculated. Mixed-model regression models examined the association between player characteristics, event type, and seasons and peak linear and rotational accelerations. Results: A total of 429 head impacts from 604 exposures occurred across the study period (IR, 7.10; 95% CI, 4.81-10.50). Weekly and seasonal cumulative median head impact frequencies were 1.00 (range, 0-2.63) and 7.50 (range, 0-21.00), respectively. The most frequent estimated head impact locations were the skull base (n = 96; 22.4%), top of the head (n = 74; 17.2%), and back of the head (n = 66; 15.4%). The combined event type IRs differed among the 3 seasons (IRR range, 1.45-2.68). Games produced greater IRs (IRR, 1.24; 95% CI, 1.01-1.53) and peak linear acceleration (mean difference, 5.69 g; P = .008) than did practices. Older players demonstrated greater combined event–type IRs (IRR, 1.46; 95% CI, 1.12-1.90) and increased head impact magnitudes than did younger players, with every 1-year age increase associated with a 3.78 g and 602.81-rad/s2 increase in peak linear and rotational acceleration magnitude, respectively ( P≤ .005). Conclusion: Head IRs and magnitudes varied across seasons, thus highlighting multiple season and cohort data are valuable when providing estimates. Head IRs were relatively low across seasons, while linear and rotational acceleration magnitudes were relatively high.

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 Kinematics by Contact Scenarios in Youth Ice Hockey

Neurology ◽  
2020 ◽  
Vol 95 (20 Supplement 1) ◽  
pp. S1.1-S1
Author(s):  
Abigail Swenson ◽  
Logan Miller ◽  
Jillian Urban ◽  
Joel Stitzel
Keyword(s):  
Rotational Velocity ◽  
Angular Acceleration ◽  
Linear Acceleration ◽  
Head Impact ◽  
Ice Hockey ◽  
Contact Sports ◽  
Head Impacts ◽  
Rigorous Study ◽  
Improving Accuracy ◽  
Impact Events

ObjectiveThe objective of this pilot study was to characterize head impact exposure in a sample of youth boys' ice hockey using a novel instrumented mouthpiece, improving accuracy.BackgroundFrom 2010 to 2018 youth ice hockey saw a 15% increase in participation, despite growing concerns for concussion risk in contact sports. While contact sports with similar rates of concussion have been subjected to rigorous study, head impact exposure in youth ice hockey has been largely underexplored. Existing youth studies have utilized helmet-mounted sensors, which are associated with error due to poor coupling with the skull.Design/MethodsCustom mouthpieces containing a tri-axial accelerometer and gyroscope were fit to seven enrolled athletes, and monitored during practices and games throughout the season. Linear acceleration and rotational velocity of the head were recorded for 60 ms when 5 g was exceeded on any axis for at least 3 ms. Time-synchronized film was reviewed to identify the contact scenario and head contact. Summary statistics of kinematics were calculated by scenario and presence of head contact.ResultsA total of 465 events were recorded over 25 weeks. Of these events 25% involved head contact; 92% of all contact scenarios were board checks, falls, or ice checks. Events involving head contact (i.e., head impacts) had median [95th percentile] peak linear acceleration, rotational velocity, and angular acceleration of 8.1 [30.9] g, 7.9 [20.2] rad/s, and 614 [2673] rad/s2, respectively. Events not involving head contact had median [95th percentile] peak linear acceleration, rotational velocity, and angular acceleration of 6.6 [43.8] g, 6.5 [17.5] rad/s, and 455 [4115] rad/s2, respectively.ConclusionsThe majority of the recorded events could be classified as board checks, falls, or ice checks. Median peak kinematics were higher for head impacts than non-head impact events. In contrast, 95th percentile linear and angular accelerations were greater for impacts not involving head contact.

Characterizing Verified Head Impacts in High School Girls’ Lacrosse

2017 ◽  
Vol 45 (14) ◽  
pp. 3374-3381 ◽  
Author(s):  
Shane V. Caswell ◽  
Andrew E. Lincoln ◽  
Hannah Stone ◽  
Patricia Kelshaw ◽  
Margot Putukian ◽  
...  
Keyword(s):  
High School ◽  
Linear Acceleration ◽  
Video Data ◽  
Sensor Data ◽  
Mastoid Process ◽  
Head Impacts ◽  
Impact Rate ◽  
Game Situation ◽  
The Right ◽  
The Impact

Background: Girls’ high school lacrosse players have higher rates of head and facial injuries than boys. Research indicates that these injuries are caused by stick, player, and ball contacts. Yet, no studies have characterized head impacts in girls’ high school lacrosse. Purpose: To characterize girls’ high school lacrosse game-related impacts by frequency, magnitude, mechanism, player position, and game situation. Study Design: Descriptive epidemiology study. Methods: Thirty-five female participants (mean age, 16.2 ± 1.2 years; mean height, 1.66 ± 0.05 m; mean weight, 61.2 ± 6.4 kg) volunteered during 28 games in the 2014 and 2015 lacrosse seasons. Participants wore impact sensors affixed to the right mastoid process before each game. All game-related impacts recorded by the sensors were verified using game video. Data were summarized for all verified impacts in terms of frequency, peak linear acceleration (PLA), and peak rotational acceleration (PRA). Descriptive statistics and impact rates were calculated. Results: Fifty-eight verified game-related impacts ≥20 g were recorded (median PLA, 33.8 g; median PRA, 6151.1 rad/s2) during 467 player-games. The impact rate for all game-related verified impacts was 0.12 per athlete-exposure (AE) (95% CI, 0.09-0.16), equivalent to 2.1 impacts per team game, indicating that each athlete suffered fewer than 2 head impacts per season ≥20 g. Of these impacts, 28 (48.3%) were confirmed to directly strike the head, corresponding with an impact rate of 0.05 per AE (95% CI, 0.00-0.10). Overall, midfielders (n = 28, 48.3%) sustained the most impacts, followed by defenders (n = 12, 20.7%), attackers (n = 11, 19.0%), and goalies (n = 7, 12.1%). Goalies demonstrated the highest median PLA and PRA (38.8 g and 8535.0 rad/s2, respectively). The most common impact mechanisms were contact with a stick (n = 25, 43.1%) and a player (n = 17, 29.3%), followed by the ball (n = 7, 12.1%) and the ground (n = 7, 12.1%). One hundred percent of ball impacts occurred to goalies. Most impacts occurred to field players within the attack area of the field (n = 32, 55.2%) or the midfield (n = 18, 31.0%). Most (95%) impacts did not result in a penalty. Conclusion: The incidence of verified head impacts in girls’ high school lacrosse was quite low. Ball to head impacts were associated with the highest impact magnitudes. While stick and body contacts are illegal in girls’ high school lacrosse, rarely did such impacts to the head result in a penalty. The verification of impact mechanisms using video review is critical to collect impact sensor data.

scholarly journals Subconcussive head impact exposure differences between drill intensities in U.S. high school football

2020 ◽  
Author(s):  
Kyle Kercher ◽  
Jesse A. Steinfeldt ◽  
Jonathan T. Macy ◽  
Keisuke Ejima ◽  
Keisuke Kawata
Keyword(s):  
High School ◽  
Linear Acceleration ◽  
Head Impact ◽  
Football Players ◽  
Impact Frequency ◽  
High School Football ◽  
Head Impacts ◽  
Air Bags ◽  
Frequency Peak ◽  
Impact Data

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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