Characterizing Head Impact Exposure in Men and Women During Boxing and Mixed Martial Arts

Background: The accumulation of subconcussive impacts has been implicated in permanent neurological impairment. A gap in understanding the relationship between head impacts and neurological function is the lack of precise characterization and quantification of forces that individuals experience during sports training and competition. Purpose: To characterize impact exposure during training and competition among male and female athletes participating in boxing and mixed martial arts (MMA) via an instrumented custom-fit Impact Monitoring Mouthguard (IMM). Study Design: Cross-sectional study; Level of evidence, 3. Methods: Twenty-three athletes (n = 4 women) were provided a custom-fit IMM. The IMM monitored impacts during sparring and competition. All training and competition sessions were videotaped. Video and IMM data were synchronized for post hoc data verification of true positives and substantiation of impact location. IMM data were collected from boxing and MMA athletes at a collaborating site. For each true-positive impact, peak linear acceleration and peak angular acceleration were calculated. Wilcoxon rank sum tests were used to evaluate potential differences in sport, activity type, and sex with respect to each outcome. Differences in impact location were assessed via Kruskal-Wallis tests. Results: IMM data were collected from 53 amateur training sessions and 6 competitions (session range, 5-20 minutes). A total of 896 head impacts (men, n = 786; women, n = 110) were identified using IMM data and video verification: 827 in practice and 69 during competition. MMA and boxers experienced a comparable number of impacts per practice session or competition. In general, MMA impacts produced significantly higher peak angular acceleration than did boxing impacts ( P < .001) and were more varied in impact location on the head during competitions. In terms of sex, men experienced a greater number of impacts than women per practice session. However, there was no significant difference between men and women in terms of impact magnitude. Conclusion: Characteristic profiles of head impact exposure differed between boxing and MMA athletes; however, the impact magnitudes were not significantly different for male and female athletes.

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Concussion and the severity of head impacts in mixed martial arts

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411920947850 ◽

2020 ◽

Vol 234 (12) ◽

pp. 1472-1483 ◽

Cited By ~ 1

Author(s):

Stephen Tiernan ◽

Aidan Meagher ◽

David O’Sullivan ◽

Eoin O’Keeffe ◽

Eoin Kelly ◽

...

Keyword(s):

Martial Arts ◽

Angular Acceleration ◽

Linear Acceleration ◽

Head Impact ◽

Sensor Technology ◽

Mixed Martial Arts ◽

Head Impacts ◽

Impact Power ◽

Average Maximum ◽

The Impact

Concern about the consequences of head impacts in US football has motivated researchers to investigate and develop instrumentation to measure the severity of these impacts. However, the severity of head impacts in unhelmeted sports is largely unknown as miniaturised sensor technology has only recently made it possible to measure these impacts in vivo. The objective of this study was to measure the linear and angular head accelerations in impacts in mixed martial arts, and correlate these with concussive injuries. Thirteen mixed martial arts fighters were fitted with the Stanford instrumented mouthguard (MiG2.0) participated in this study. The mouthguard recorded linear acceleration and angular velocity in 6 degrees of freedom. Angular acceleration was calculated by differentiation. All events were video recorded, time stamped and reported impacts confirmed. A total of 451 verified head impacts above 10g were recorded during 19 sparring events (n = 298) and 11 competitive events (n = 153). The average resultant linear acceleration was 38.0624.3g while the average resultant angular acceleration was 256761739 rad/s2. The competitive bouts resulted in five concussions being diagnosed by a medical doctor. The average resultant acceleration (of the impact with the highest angular acceleration) in these bouts was 86.7618.7g and 756163438 rad/s2. The average maximum Head Impact Power was 20.6kW in the case of concussion and 7.15kW for the uninjured athletes. In conclusion, the study recorded novel data for sub-concussive and concussive impacts. Events that resulted in a concussion had an average maximum angular acceleration that was 24.7% higher and an average maximum Head Impact Power that was 189% higher than events where there was no injury. The findings are significant in understanding the human tolerance to short-duration, high linear and angular accelerations.

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Rapid Weight Gain Following Weight Cutting in Male and Female Professional Mixed Martial Artists

International Journal of Sport Nutrition and Exercise Metabolism ◽

10.1123/ijsnem.2020-0369 ◽

2021 ◽

pp. 1-9

Author(s):

Kadhiresan R. Murugappan ◽

Ariel Mueller ◽

Daniel P. Walsh ◽

Shahzad Shaefi ◽

Akiva Leibowitz ◽

...

Keyword(s):

Weight Loss ◽

Weight Gain ◽

Body Mass ◽

Martial Arts ◽

Female Athletes ◽

Rapid Weight Loss ◽

Mixed Martial Arts ◽

Rapid Weight Gain ◽

Male And Female ◽

Small Series

Rapid weight loss or “weight cutting” is a common but potentially harmful practice used in mixed martial arts competition. Following the official weigh-in, competitors refeed and rehydrate themselves in a process known as rapid weight gain (RWG) to realize a potential competitive advantage. While data from surveys and small series have indicated the majority of mixed martial arts athletes engage in rapid weight loss, there is a lack of officially collected data from sanctioning organizations describing its prevalence. The present investigation represents a summary of the data collected between December 2015 and January 2018 by the California State Athletic Commission. In total, 512 professional mixed martial artists (455 males and 57 females) were included. Of these, 503 (98%) athletes gained body mass between weigh-in and their bouts. Total RWG between weigh-in and competition was 5.5 ± 2.5 kg, corresponding to an 8.1% ± 3.6% body mass increase. Total RWG was 5.6 ± 2.5 kg (8.1% ± 3.6%) for males and 4.5 ± 2.3 kg (8.0% ± 3.8%) for females. More than one quarter of men and one third of women gained >10% body mass between weigh-in and competition. Athletes from leading international promotions gained more absolute, but not relative, body mass than those from regional promotions. Our findings indicate RWG is nearly ubiquitous in professional , with a similar prevalence in male and female athletes. Trends based on promotion suggest a larger magnitude of RWG in presumably more experienced and/or successful mixed martial artists from leading international promotions.

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Comparative analysis of indicators of competitive activity of the strongest male and female fighters of mixed martial arts MMA

Єдиноборства ◽

10.15391/ed.2021-4.07 ◽

2021 ◽

pp. 71-87

Author(s):

Y. Tropin ◽

Y. Myroshnychenho ◽

I. Holovach ◽

I. Chornii ◽

M. Latyshev

Keyword(s):

Comparative Analysis ◽

Martial Arts ◽

The United States ◽

Standing Position ◽

The Body ◽

Mixed Martial Arts ◽

Men And Women ◽

Male And Female ◽

Competitive Activity ◽

Female Fighters

Purpose: to conduct a comparative analysis of the indicators of the competitive activity of the strongest fighters of men and women of mixed martial arts MMA from the TOP-10, regardless of weight. Material and methods. The research used the following methods: analysis of scientific and methodological information and Internet sources; generalization of best practical experience; analysis of protocols and videos of the competitive activity of men and women fighters from the TOP-10, regardless of weight; methods of mathematical statistics. The performance output of the strongest male and female MMA fighters is taken from the UFC website. Results: the analysis of the strongest fighters of women and men from the TOP-10, regardless of weight, showed that the average age of women is 32,7±3,74 years, and of men – 33,2±2,75 years. The average fight time for women is 16,25±3,43 minutes, and for men – 12,76±3,05 minutes. The TOP-10 strongest female fighters, regardless of weight, include representatives of six countries (four fighters from the United States, two representatives from Brazil and one athlete each from Kyrgyzstan, China, and the Netherlands), and the TOP-10 strongest male fighters regardless of weight also includes representatives of six countries (four fighters from the USA, two representatives from Russia and one athlete each from France, Nigeria, Brazil, Australia). It was found that male fighters from the TOP-10, regardless of weight, during their sports careers won 204 fights and lost 17 fights. For female fighters, these results are worse – 151 wins and 35 losses. Conclusions. Comparative analysis of the indicators of the competitive activity of the strongest fighters of women and men from the TOP-10, regardless of weight, showed that fighters of women and men deliver the same number of punches per minute (4,52 punches), and women fighters miss more punches (3,36 punches) than male fighters (2,60 strokes). The greatest number of punches was carried out by women and men in a standing position (women – 66,9 %; men – 64,6 %), then on the ground (women – 19,0 %; men – 21,6 %) and in a clinch (women – 14,1 %; men – 13,8 %). The largest number of blows are in the head (women – 60,2 %; men – 68,4 %), then on the body (women – 20,9 %; men – 18,3 %) and on the legs (women – 18,9 %; men – 13,3 %). The strongest fighters, women and men, defend against takedowns more efficiently (women – 77,5 %; men – 81,6 %) than against punches (women – 56,8 %; men – 59,8 %). The number of takedown attempts in 15 minutes is greater (women – 1,53 times; men – 1,86 times) than performing a submission in 15 minutes (women – 0,55 times; men – 0,53 times). Keywords: competitive activity, mixed martial arts MMA, TOP-10, indicators, fighters, men, women.

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Comparison of Head Impact Exposure Between Male and Female High School Ice Hockey Athletes

The American Journal of Sports Medicine ◽

10.1177/0363546518777244 ◽

2018 ◽

Vol 46 (9) ◽

pp. 2253-2262 ◽

Cited By ~ 8

Author(s):

James T. Eckner ◽

Kathryn L. O’Connor ◽

Steven P. Broglio ◽

James A. Ashton-Miller

Keyword(s):

High School ◽

Angular Acceleration ◽

Sports Participation ◽

Head Impact ◽

Ice Hockey ◽

Mastoid Process ◽

Male And Female ◽

Head Impacts ◽

Female High School ◽

The Impact

Background: Concussion incidence rates are higher among female than male athletes in sports played by both sexes. Biomechanical factors may play a role in observed sex-based differences in concussion incidence. Purpose: To compare head impact counts and magnitudes during sports participation between male and female high school ice hockey athletes. Study Design: Cohort study; Level of evidence, 2. Methods: Over 2 seasons, a total of 21 male and 19 female ice hockey athletes from a single high school were instrumented with impact-sensing adhesive skin patches worn over the mastoid process while participating in games and practices. The impact sensors recorded the number, magnitude (peak linear acceleration [PLA, g] and peak angular acceleration [PAA, rad/s2] of the head; Head Impact Telemetry severity profile [HITsp]), and location of impacts sustained during each instrumented session. Head impact counts, magnitudes, and locations were compared between the sexes. Results: Males experienced more head impacts than females during games (mean ± SD: 7.7 ± 3.0 vs 5.3 ± 2.0, P < .001) as well as practices (4.3 ± 1.6 vs 3.8 ± 1.1, P = .002). Mean impact magnitudes were greater for females for PLA (18.8 g ± 1.7 g vs 17.1 g ± 1.6 g, P < .001) and HITsp (19.7 ± 1.5 vs 17.7 ± 1.4, P < .001), while mean PAA was greater for males (3057.6 ± 2.0 rad/s2 vs 2778.3 ± 2.7 rad/s2, P < .001). Female athletes experienced higher PLA, PAA, and HITsp magnitudes for the top 10%, 5%, and 1% of impacts (all P < .050). Males experienced more impacts to the front (34.3%) and back (31.7%) of the head, while females experienced more impacts to the side (43.1%) and top (4.1%) (χ2 = 295.70, df = 3, P < .001). Conclusion: While male high school ice hockey athletes experienced more head impacts than females, impact magnitudes tended to be higher for females.

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Ultra Trail Performance is Differently Predicted by Endurance Variables in Men and Women

International Journal of Sports Medicine ◽

10.1055/a-1255-3083 ◽

2020 ◽

Cited By ~ 1

Author(s):

Ignacio Martinez-Navarro ◽

Antonio Montoya-Vieco ◽

Eladio Collado ◽

Bárbara Hernando ◽

Carlos Hernando

Keyword(s):

Oxygen Uptake ◽

Female Athletes ◽

Fat Oxidation ◽

Peak Oxygen Uptake ◽

Significant Variable ◽

Men And Women ◽

Male And Female ◽

Race Time ◽

Maximal Fat Oxidation ◽

Peak Speed

AbstractThe study aimed to assess the relationship between peak oxygen uptake, ventilatory thresholds and maximal fat oxidation with ultra trail male and female performance. 47 athletes (29 men and 18 women) completed a cardiopulmonary exercise test between 2 to 4 weeks before a 107-km ultra trail. Body composition was also analyzed using a bioelectrical impedance weight scale. Exploratory correlation analyses showed that peak oxygen uptake (men: r=–0.63, p=0.004; women: r=–0.85, p < 0.001), peak speed (men: r=–0.74, p < 0.001; women: r=–0.69, p=0.009), speed at first (men: r=–0.49, p=0.035; women: r=–0.76, p=0.003) and second (men: r=–0.73, p < 0.001; women: r=–0.76, p=0.003) ventilatory threshold, and maximal fat oxidation (men: r=–0.53, p=0.019; women: r=–0.59, p=0.033) were linked to race time in male and female athletes. Percentage of fat mass (men: r=0.58, p=0.010; women: r=0.62, p= 0.024) and lean body mass (men: r=–0.61, p=0.006; women: r=–0.61, p=0.026) were also associated with performance in both sexes. Subsequent multiple regression analyses revealed that peak speed and maximal fat oxidation together were able to predict 66% of male performance; while peak oxygen uptake was the only statistically significant variable explaining 69% of the variation in women’s race time. These results, although exploratory in nature, suggest that ultra trail performance is differently predicted by endurance variables in men and women.

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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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Head Kinematics by Contact Scenarios in Youth Ice Hockey

Neurology ◽

10.1212/wnl.0000000000011045 ◽

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.

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Head-Impact–Measurement Devices: A Systematic Review

Journal of Athletic Training ◽

10.4085/1062-6050.52.2.05 ◽

2017 ◽

Vol 52 (3) ◽

pp. 206-227 ◽

Cited By ~ 48

Author(s):

Kathryn L. O'Connor ◽

Steven Rowson ◽

Stefan M. Duma ◽

Steven P. Broglio

Keyword(s):

Clinical Utility ◽

Female Athletes ◽

Error Rates ◽

Head Impact ◽

Ice Hockey ◽

Diagnostic Methods ◽

Biomechanical Analysis ◽

Targeted Prevention ◽

Head Impacts ◽

Google Search

Context:With an estimated 3.8 million sport- and recreation-related concussions occurring annually, targeted prevention and diagnostic methods are needed. Biomechanical analysis of head impacts may provide quantitative information that can inform both prevention and diagnostic strategies.Objective:To assess available head-impact devices and their clinical utility.Data Sources:We performed a systematic search of the electronic database PubMed for peer-reviewed publications, using the following phrases: accelerometer and concussion, head impact telemetry, head impacts and concussion and sensor, head impacts and sensor, impact sensor and concussion, linear acceleration and concussion, rotational acceleration and concussion, and xpatch concussion. In addition to the literature review, a Google search for head impact monitor and concussion monitor yielded 15 more devices.Study Selection:Included studies were performed in vivo, used commercially available devices, and focused on sport-related concussion.Data Extraction:One author reviewed the title and abstract of each study for inclusion and exclusion criteria and then reviewed each full-text article to confirm inclusion criteria. Controversial articles were reviewed by all authors to reach consensus.Data Synthesis:In total, 61 peer-reviewed articles involving 4 head-impact devices were included. Participants in boxing, football, ice hockey, soccer, or snow sports ranged in age from 6 to 24 years; 18% (n = 11) of the studies included female athletes. The Head Impact Telemetry System was the most widely used device (n = 53). Fourteen additional commercially available devices were presented.Conclusions:Measurements collected by impact monitors provided real-time data to estimate player exposure but did not have the requisite sensitivity to concussion. Proper interpretation of previously reported head-impact kinematics across age, sport, and position may inform future research and enable staff clinicians working on the sidelines to monitor athletes. However, head-impact–monitoring systems have limited clinical utility due to error rates, designs, and low specificity in predicting concussive injury.

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High Energy American Football Head Impacts to the Side and Rear Damaging Than to the Front

Neurology ◽

10.1212/01.wnl.0000580920.17339.01 ◽

2019 ◽

Vol 93 (14 Supplement 1) ◽

pp. S10.1-S10

Author(s):

Adam Bartsch ◽

Edward Benzel ◽

Sergey Samorezov ◽

Vincent Miele

Keyword(s):

High Energy ◽

Head Impact ◽

American Football ◽

Dose Response Relationship ◽

Positive Events ◽

Head Impacts ◽

Injury Threshold ◽

Impact Location ◽

Player Game ◽

Concussive Injury

ObjectiveThe aim of this study was to investigate head impact doses in American football. We analyzed time-synchronized video and data collected during n = 445 player-games of American football resulting in 2851video-verified impacts. Cases where a player sustained impacts and on video was demonstrably witnessed to meet the NFL’s “No-go” criteria were analyzed in-depth.BackgroundIn 2011, after reviewing scalar on-field kinematics data leading concussion clinicians concluded “Recent studies suggest that a concussive injury threshold is elusive, and may, in fact, be irrelevant when predicting the clinical outcome”.1 It is likely that higher fidelity estimates of spatial and temporal impact parameters will clarify the currently unclear impact dose-response relationship.Design/MethodsA total of 2851 video-verified head impacts were identified from 445 player-games. Each event was time-synchronized to video. Any events collected when the athlete was not being impacted in the head were discarded. The remaining true positive events were scrutinized based on published methods to confirm a head impact occurred in the video and the computed motion was physically realistic and matched the video.ResultsWe found a median of 5 video-verified head impacts per player-game, which is far fewer than published studies without video verification.11 For the four players with “No-go” impacts, all were to the side/rear. Coronal plane impact sensitivity has been a hypothesized clinical injury mechanism12 and our results support that hypothesis.ConclusionsWe did not see high PLA/PAA impacts without obvious player “No-go” observations. This finding disagrees with other studies that have reported high PLA/PAA impacts without any demonstrable “No-go” observations13. High energy impacts to the side and rear of the head are more damaging than similar magnitude impacts to the forehead. Armed with this knowledge, clinicians should have more fidelity in their understanding of real-time impact location and severity, and how it relates to athlete concussion risk.

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Head Impact Exposure and Mechanisms in Female High School Lacrosse via an Instrumented Mouthguard

Neurology ◽

10.1212/01.wnl.0000801856.45976.d2 ◽

2021 ◽

Vol 98 (1 Supplement 1) ◽

pp. S13.2-S14

Author(s):

Colin M. Huber ◽

Declan A. Patton ◽

Susan Margulies ◽

Christina Master ◽

Kristy Arbogast

Keyword(s):

High School ◽

Angular Acceleration ◽

Head Impact ◽

Sensor Data ◽

Current Debate ◽

Protective Equipment ◽

Impact Mechanism ◽

Head Impacts ◽

Impact Biomechanics ◽

Female High School

ObjectiveTo quantify the head impact biomechanics, by impact mechanism, of female high school lacrosse players during games using an instrumented mouthguard.BackgroundThere is growing concern for the neurologic effects of repetitive head impacts in sports, which have been linked with several short-term neurophysiologic deficits. Girls' lacrosse represents a popular but understudied sport with regard to head impact exposure and current debate exists as to the need for enhanced protective equipment.Design/MethodsA female high school varsity lacrosse team wore the Stanford Instrumented Mouthguard during competitive games for the 2019 season. Video footage was reviewed to confirm head impact events and remove false-positive recordings. For each impact event, the mechanism was coded as stick contact, player contact, fall, or ball contact. Head impact rates were calculated per athlete exposure (AE, defined as a single player participating in a single game).ResultsSensor data were recorded for 15 female varsity lacrosse players for 14 games and 97 AEs. During games, 31 sensor-recorded head impacts were video-confirmed resulting in a pooled average head impact rate of 0.32 impacts/AE. The video-confirmed impacts were distributed between stick contact (17, 54.8%), player contact (12, 38.7%), and falls (2, 6.5%). There were no ball impacts. Overall peak kinematics were 34.0 ± 26.6 g, 12.0 ± 9.1 rad/s, and 3,666.5 ± 2,987.6 rad/s2. Stick contacts had the highest peak linear acceleration (42.7 ± 32.2 g), angular velocity (14.5 ± 11.1 rad/s), and angular acceleration (4,242.4 ± 3,634.9 rad/s2).ConclusionsStick impacts were the most common impact mechanism and resulted in the highest peak linear and angular kinematics, which may help explain why they are the most common cause of head injury in female lacrosse. By quantifying the head impact exposure, kinematics and mechanisms in female high school lacrosse, targeted injury preventions can be developed, such as rule changes and protective equipment.

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