Head Impact Exposure in Girls’ High School Varsity Lacrosse Players

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.

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Biomechanical head impact characteristics during sparring practice sessions in high school taekwondo athletes

Journal of Neurosurgery Pediatrics ◽

10.3171/2017.1.peds16432 ◽

2017 ◽

Vol 19 (6) ◽

pp. 662-667 ◽

Cited By ~ 3

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.

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Abnormal White Matter Integrity Related to Head Impact Exposure in a Season of High School Varsity Football

Journal of Neurotrauma ◽

10.1089/neu.2013.3233 ◽

2014 ◽

Vol 31 (19) ◽

pp. 1617-1624 ◽

Cited By ~ 133

Author(s):

Elizabeth M. Davenport ◽

Christopher T. Whitlow ◽

Jillian E. Urban ◽

Mark A. Espeland ◽

Youngkyoo Jung ◽

...

Keyword(s):

High School ◽

White Matter ◽

Head Impact ◽

White Matter Integrity

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Does Visual Performance Influence Head Impact Severity Among High School Football Athletes?

Clinical Journal of Sport Medicine ◽

10.1097/jsm.0000000000000143 ◽

2014 ◽

pp. 1 ◽

Cited By ~ 2

Author(s):

Julianne D. Schmidt ◽

Kevin M. Guskiewicz ◽

Jason P. Mihalik ◽

J. Troy Blackburn ◽

Gunter P. Siegmund ◽

...

Keyword(s):

High School ◽

Head Impact ◽

Visual Performance ◽

High School Football

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

10.1101/2020.03.29.20047167 ◽

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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Association of physiological variables with football subconcussive head impacts: Why measure?

10.1101/493700 ◽

2018 ◽

Author(s):

Megan E. Huibregtse ◽

Steven W. Zonner ◽

Keisuke Ejima ◽

Zachary W. Bevilacqua ◽

Sharlene Newman ◽

...

Keyword(s):

High School ◽

Skeletal Muscle ◽

Heart Rate ◽

Muscle Damage ◽

Physical Exertion ◽

Head Impact ◽

American Football ◽

Physiological Factors ◽

Head Impacts ◽

Skeletal Muscle Damage

AbstractSubconcussive head impacts, defined as impacts to the cranium that do not result in clinical symptoms of concussion, are gaining traction as a major public health concern. Researchers begin to suggest subconcussive impact-dependent changes in various neurological measures. However, a contribution of physiological factors such as physical exertion and muscle damage has never been accounted. We conducted a prospective longitudinal study during a high school American football season to examine the association between physiological factors and subconcussive head impact kinematics. Fifteen high-school American football players volunteered in the study. A sensor-installed mouthguard recorded the number of head impacts, peak linear (PLA: g) and peak rotational (PRA: rad/s2) head accelerations from every practice and game. Serum samples were collected at 12 time points (pre-season baseline, five in-season pre-post games, and post-season) and assessed for the creatine kinase skeletal muscle-specific isoenzyme (CK-MM), as a surrogate for skeletal muscle damage. Physical exertion was estimated in the form of excess post-exercise oxygen consumption (EPOC) from heart rate data captured during five games via a wireless heart rate monitor. A total of 9,700 hits, 214,492 g, and 19,885,037 rad/s2 were recorded from 15 players across the study period. Mixed-effect regression models indicated that head impact kinematics (frequency, PLA, and PRA) were significantly and positively associated with CK-MM increase, but not with EPOC. There was a significant and positive association between CK-MM and EPOC. These data suggest that skeletal muscle damage effects should be considered when using outcome measures that may have an interaction with muscle damage, including inflammatory biomarkers and vestibular/balance tests.

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