Professional Fighters Research Articles

Concussion reporting and perceived knowledge of professional fighters

ABSTRACTObjective: For concussions to be effectively managed in sports, they need to be correctly identified and reported. The extent to which professional athletes correctly recognize concussions, and their willingness to report symptoms, is not yet well understood. Given the risk of head injuries leading to concussions across combat sports, insight into professional fighters’ knowledge and reporting of concussive symptoms is essential to improve concussion management.Methods: To investigate understanding and reporting patterns of concussions sustained while training or competing, 257 fighters completed a self-report questionnaire assessing self-perception of concussion knowledge, trust of ringside medical providers, and reported number of previous head injuries. Fighting history, including number of knockouts, was obtained from self-report (amateur) and published (professional) records.Results: Significant gaps in fighters’ perceived knowledge of concussion symptoms and long-term effects of multiple concussions emerged. Approximately 40% of fighters reported returning to training or competition the same day a head injury was sustained, while 21% of fighters endorsed concealing symptoms of head injury from medical providers and coaches.Conclusions: Confusion surrounding terms used to describe head injuries amongst fighters (e.g., concussions, knockouts), coupled with limited understanding of concussive symptoms and a desire to return to competition, likely contributes to significant underreporting of symptoms.

Muay Thai: Women, fighting, femininity

Women fighting challenges conventional notions of femininity in many ways. A bleeding nose, bruised eyes and swollen lips embody perhaps masculine success but, for many, constitute failed femininity. Yet women fighters, who are attracting unprecedented media attention, are in novel ways forcing a re-imagination of femininity. This article draws on 17 in-depth semi-structured interviews with professional and amateur female Muay Thai fighters based in Thailand to explore the subversion and reinvention, and also reinforcement, of feminine norms. Theoretically, we advance the debate around fighting and femininity by developing the concept of bio-borders to investigate the presentation, protection and penetration of bodily femininity. We conclude that women fighters inspire a femininity recognising physical and emotional strength alongside conventional feminine norms of beauty, relationality and compliance.

Longitudinal Performance of Plasma Neurofilament Light and Tau in Professional Fighters: The Professional Fighters Brain Health Study.

The aim of this study is to evaluate longitudinal change in plasma neurofilament light (NF-L) and tau levels in relationship to clinical and radiological measures in professional fighters. Participants (active and retired professional fighters and control group) underwent annual blood sampling, 3-Tesla magnetic resonance imaging (MRI) brain imaging, computerized cognitive testing, and assessment of exposure to traumatic brain injury. Plasma tau and NF-L concentrations were measured using Simoa assays. Multiple linear regression models were used to compare the difference across groups in regard to baseline measurements, whereas mixed linear models was used for the longitudinal data with multiple measurements for each participant. Plasma samples were available on 471 participants. Baseline NF-L measures differed across groups (F3,393 = 6.99; p = 0.0001), with the active boxers having the highest levels. Higher NF-L levels at baseline were correlated with lower baseline MRI regional volumes and lower cognitive scores. The number of sparring rounds completed by the active fighters was correlated with NF-L (95% confidence interval, 0.0116-0.4053; p = 0.0381), but not tau, levels. Among 126 subjects having multiple yearly samples, there was a significant difference in average yearly percentage change in tau across groups (F3,83 = 3.87; p = 0.0121). We conclude that plasma NF-L and tau behave differently in a group of active and retired fighters; NF-L better reflects acute exposure whereas the role of plasma tau levels in signifying chronic change in brain structure over time requires further study.

A Systematic Review of Positron Emission Tomography of Tau, Amyloid Beta, and Neuroinflammation in Chronic Traumatic Encephalopathy: The Evidence To Date.

Chronic traumatic encephalopathy (CTE) is associated with pathological changes, yet detecting these changes during life has proven elusive. Positron emission tomography (PET) offers the potential for identifying such pathology. Few studies have been completed to date and their approaches and results have been diverse. It was the objective of this review to systematically examine relevant research using ligands for PET that bind to identified pathology in CTE. We focused on identification of patterns of binding and addressing gaps in knowledge of PET imaging for CTE. A comprehensive literature search was conducted. Data used were published on or before May 22, 2017. As the extant literature is limited, any peer-reviewed article assessing military, contact sports athletes, or professional fighters was considered for inclusion. The main outcomes were regional binding to brain regions identified through control comparisons or through clinical metrics (e.g., standardized uptake volume ratios). A total of 1207 papers were identified for review, of which six met inclusion criteria. Meta-analyses were planned but were deemed inappropriate given the small number of studies identified. Methodological concerns in these initial papers included small sample sizes, lack of a control comparison, use of nonstandard statistical procedures to quantify data, and interpretation of potentially off-target binding areas. Across studies, the hippocampi, amygdalae, and midbrain had reasonably consistent increased uptake. Evidence for increased uptake in cortical regions was less consistent. The evidence suggests that the field of PET imaging in those at risk for CTE remains nascent. As the field evolves to include more stringent studies, ligands for PET may prove an important tool in identifying CTE in vivo.

Longitudinal Changes in Depression and Cognition in Professional Fighters with Baseline Structural Imaging: The Role of Depression in Cognitive Change and Structural Differences. (S49.004)

Longitudinal Changes in Depression and Cognition in Professional Fighters with Baseline Structural Imaging: The Role of Depression in Cognitive Change and Structural Differences. (S49.004)

Acute neuromuscular responses to short and long roundhouse kick striking paces in professional Muay Thai fighters.

Muay Thai fighters strongly rely on the use of the roundhouse kick due to its effectiveness (i.e. power) and implications on the final score. Therefore, different striking tempos at full power are used during training as a method to enhance kicking power. However, the neuromuscular responses are unknown. Thus, the goal of this study was to investigate neuromuscular responses to a single bout of shorter (every second = H1) and longer (every 3 s = H3) kick striking time intervals, measured with the countermovement jump (CMJ). Nine professional Muay Thai fighters participated in this randomized, cross-over trial. CMJs were measured on force plates before and after (at 0, 5, 10, 20, and 30 minutes) two striking (1 set ×20 reps) conditions (H1; H3). Although no difference was observed between H1 and H3 values, neuromuscular fatigue parameters displayed different patterns over time. CMJ height decreased immediately after H3 striking (P<0.05), whereas for H1 condition CMJ height decreased from 20 minutes as compared to baseline (P<0.05). Peak force in H3 condition was significantly lower at 10, 20, and 30 minutes as compared to baseline. For H1, peak force values were lower than baseline only at 30 minutes. Peak power was significantly lower than baseline for both middle kick procedures. A slight but significant increase was observed at 5 minutes for H3 condition but decreased further at 10 minutes and remained constant during subsequent tests. In contrast, for H1 condition, peak power remained unaffected after 10 minutes, whereas it decreased at 20 and 30 minutes only when compared to minute 0. Results showed that both kick striking modes provoke comparable neuromuscular fatigue but H3 condition showed the potential to induce post activation potentiation. Muay Thai and conditioning coaches should focus on hard striking with both long and slow pacing during specific heavy bag or pad work.

Force-Velocity Relationship in Three Different Variations of Prone Row Exercises.

Loturco, I, Suchomel, T, Kobal, R, Arruda, AFS, Guerriero, A, Pereira, LA, and Pai, CN. Force-velocity relationship in three different variations of prone row exercises. J Strength Cond Res 35(2): 300-309, 2021-This study examined the force-velocity relationship and tested the possibility of determining the relative loading intensity percentage of 1 repetition maximum (%1RM) in 3 different variations of prone row exercises. Thirty male top-level athletes from 2 different sports (National Team rugby union players and professional mixed martial arts fighters) were submitted to maximum dynamic strength assessments in the free prone bench pull, bent-over barbell row, and bent-over Smith machine row, after standard procedures encompassing lifts performed from 40 to 100% of 1RM. The mean velocity, mean propulsive velocity, and peak velocity were measured in all attempts. Linear regression analyses were performed to establish the relationships between the different measures of bar velocities and %1RM. The actual (obtained during the assessments) and predicted 1RM values (based on the predictive equations) for each exercise were compared using a paired t-test. In all exercises, the predicted 1RM scores-based on all velocity variables-were not different from their respective actual values. The close linear relationships between bar velocities and distinct %1RM (coefficient of determination ≥80%, in all experimental conditions) allow precise determination of relative load and maximum dynamic strength, and enable coaches and sports scientists to use the different velocity outputs to rapidly and accurately monitor their athletes on a daily basis.

A fat mass and obesity-associated gene polymorphism influences fat mass in exercise-trained individuals

BackgroundA single nucleotide polymorphism (SNP) in the fat mass and obesity-associated (FTO) gene is a strong predictor of obesity in humans. The FTO SNP (rs1421085) results in a T to C nucleotide substitution that may result in an increased risk for obesity in individuals who carry at least one C allele. The purpose of this investigation was to characterize the FTO genotype in a cohort of exercise-trained men and women.MethodsWe tested 108 exercise-trained individuals that included professional mixed martial arts fighters, competitive distance runners, collegiate swimmers, stand-up paddlers as well as a cohort of recreational bodybuilders. Body composition was assessed via dual-energy x-ray absorptiometry (DXA). Saliva samples were collected in order to genotype participants and quantify cortisol levels.ResultsThe physical characteristics of the subjects were as follows (mean±SD): body weight 74.5±15.6 kg; height 171.5±9.5 cm; bone mineral content 2.8±0.7 kg; fat mass 15.7±5.5 kg; lean body mass 55.9±14.4 kg; % body fat 21.6±7.0. Independent samples t tests showed that C allele carriers (n = 54) had significantly higher fat mass t(106) = 3.13, p < 0.01 and body fat percentage t(106) = 2.68, p < 0.01, relative to the TT group (n = 54) (i.e., fat mass: C/− 17.3 ±5.6 kg, TT 14.2±4.6 kg; body fat percentage: C/− group 23.4±7.4%, TT group 19.9±6.2). No other measures of body composition were associated with the FTO genotype (i.e., body mineral density, bone mineral content, or lean body mass). Moreover, cortisol levels were significantly higher in the TT group relative to the C allele carriers t(106) = 2.37, p = 0.02 (i.e., TT 0.35 ±0.35 μg/dL, C/− 0.22±0.16 μg/dL).ConclusionsOur findings demonstrate a relationship between C allele carriers on the FTO gene and a predisposition to a higher fat mass and body fat percentage. In addition, we found no relationship between cortisol and fat mass. However, due to the cross-sectional nature of this investigation, we cannot infer causality regarding the FTO gene and body composition.

Investigating structural and perfusion deficits due to repeated head trauma in active professional fighters.

Repeated head trauma experienced by active professional fighters results in various structural, functional and perfusion damage. However, whether there are common regions of structural and perfusion damage due to fighting and whether these structural and perfusion differences are associated with neuropsychological measurements in active professional fighters is still unknown. To that end, T1-weighted and pseudocontinuous arterial spin labeling MRI on a group of healthy controls and active professional fighters were acquired. Voxelwise group comparisons, in a univariate and multivariate sense, were performed to investigate differences in gray and white matter density (GMD, WMD) and cerebral blood flow (CBF) between the two groups. A significantly positive association between global GMD and WMD was obtained with psychomotor speed and reaction time, respectively, in our cohort of active professional fighters. In addition, regional WMD deficit was observed in a cluster encompassing bilateral pons, hippocampus, and thalamus in fighters (0.49 ± 0.04 arbitrary units (a.u.)) as compared to controls (0.51 ± 0.05a.u.). WMD in the cluster of active fighters was also significantly associated with reaction time. Significantly lower CBF was observed in right inferior temporal lobe with both partial volume corrected (46.9 ± 14.93 ml/100 g/min) and non-partial volume corrected CBF maps (25.91 ± 7.99 ml/100 g/min) in professional fighters, as compared to controls (65.45 ± 22.24 ml/100 g/min and 35.22 ± 12.18 ml/100 g/min respectively). A paradoxical increase in CBF accompanying right cerebellum and fusiform gyrus in the active professional fighters (29.52 ± 13.03 ml/100 g/min) as compared to controls (19.43 ± 12.56 ml/100 g/min) was observed with non-partial volume corrected CBF maps. Multivariate analysis with both structural and perfusion measurements found the same clusters as univariate analysis in addition to a cluster in right precuneus. Both partial volume corrected and non-partial volume corrected CBF of the cluster in the thalamus had a significantly positive association with the number of fights. In addition, GMD of the cluster in right precuneus was significantly associated with psychomotor speed in our cohort of active professional fighters. Our results suggest a heterogeneous pattern of structural and CBF deficits due to repeated head trauma in active professional fighters. This finding indicates that investigating both structural and CBF changes in the same set of participants may help to understand the pathophysiology and progression of cognitive decline due to repeated head trauma.

Age at First Exposure to Repetitive Head Impacts Is Associated with Smaller Thalamic Volumes in Former Professional American Football Players.

Thalamic atrophy has been associated with exposure to repetitive head impacts (RHI) in professional fighters. The aim of this study is to investigate whether or not age at first exposure (AFE) to RHI is associated with thalamic volume in symptomatic former National Football League (NFL) players at risk for chronic traumatic encephalopathy (CTE). Eighty-six symptomatic former NFL players (mean age = 54.9 ± 7.9 years) were included. T1-weighted data were acquired on a 3T magnetic resonance imager, and thalamic volumes were derived using FreeSurfer. Mood and behavior, psychomotor speed, and visual and verbal memory were assessed. The association between thalamic volume and AFE to playing football and to number of years playing was calculated. Decreased thalamic volume was associated with more years of play (left: p = 0.03; right: p = 0.03). Younger AFE was associated with decreased right thalamic volume (p = 0.014). This association remained significant after adjusting for total years of play. Decreased left thalamic volume was associated with worse visual memory (p = 0.014), whereas increased right thalamic volume was associated with fewer mood and behavior symptoms (p = 0.003). In our sample of symptomatic former NFL players at risk for CTE, total years of play and AFE were associated with decreased thalamic volume. The effect of AFE on right thalamic volume was almost twice as strong as the effect of total years of play. Our findings confirm previous reports of an association between thalamic volume and exposure to RHI. They suggest further that younger AFE may result in smaller thalamic volume later in life.

Multimodal MR Imaging Signatures of Cognitive Impairment in Active Professional Fighters.

Purpose To investigate whether combining multiple magnetic resonance (MR) imaging modalities such as T1-weighted and diffusion-weighted MR imaging could reveal imaging biomarkers associated with cognition in active professional fighters. Materials and Methods Active professional fighters (n = 297; 24 women and 273 men) were recruited at one center. Sixty-two fighters (six women and 56 men) returned for a follow-up examination. Only men were included in the main analysis of the study. On the basis of computerized testing, fighters were separated into the cognitively impaired and nonimpaired groups on the basis of computerized testing. T1-weighted and diffusion-weighted imaging were performed, and volume and cortical thickness, along with diffusion-derived metrics of 20 major white matter tracts were extracted for every subject. A classifier was designed to identify imaging biomarkers related to cognitive impairment and was tested in the follow-up dataset. Results The classifier allowed identification of seven imaging biomarkers related to cognitive impairment in the cohort of active professional fighters. Areas under the curve of 0.76 and 0.69 were obtained at baseline and at follow-up, respectively, with the optimized classifier. The number of years of fighting had a significant (P = 8.8 × 10-7) negative association with fractional anisotropy of the forceps major (effect size [d] = 0.34) and the inferior longitudinal fasciculus (P = .03; d = 0.17). A significant difference was observed between the impaired and nonimpaired groups in the association of fractional anisotropy in the forceps major with number of fights (P = .03, d = 0.38) and years of fighting (P = 6 × 10-8, d = 0.63). Fractional anisotropy of the inferior longitudinal fasciculus was positively associated with psychomotor speed (P = .04, d = 0.16) in nonimpaired fighters but no association was observed in impaired fighters. Conclusion Without enforcement of any a priori assumptions on the MR imaging-derived measurements and with a multivariate approach, the study revealed a set of seven imaging biomarkers that were associated with cognition in active male professional fighters. © RSNA, 2017 Online supplemental material is available for this article.

Prevalence of Traumatic Findings on Routine MRI in a Large Cohort of Professional Fighters.

Previous studies investigating MR imaging abnormalities among fighters have had small sample sizes. This investigation assessed a large number of fighters using the same conventional sequences on the same scanner. Conventional 3T MR imaging was used to assess 499 fighters (boxers, mixed martial artists, and martial artists) and 62 controls for nonspecific WM changes, cerebral microhemorrhage, cavum septum pellucidum, and cavum vergae. The lengths of the cavum septum pellucidum and cavum vergae and the ratio of cavum septum pellucidum to the septum pellucidum lengths were assessed. The prevalence of nonspecific WM changes was similar between groups. Fighters had a prevalence of cerebral microhemorrhage (4.2% versus 0% for controls, P = .152). Fighters had a higher prevalence of cavum septum pellucidum versus controls (53.1% versus 17.7%, P < .001) and cavum vergae versus controls (14.4% versus 0%, P < .001). The lengths of the cavum septum pellucidum plus the cavum vergae (P < .001), cavum septum pellucidum (P = .025), and cavum septum pellucidum to the septum pellucidum length ratio (P = .009) were higher in fighters than in controls. The number of fights slightly correlated with cavum septum pellucidum plus cavum vergae length (R = 0.306, P < .001) and cavum septum pellucidum length (R = 0.278, P < .001). When fighters were subdivided into boxers, mixed martial artists, and martial artists, results were similar to those in the whole-group analysis. This study assessed MR imaging findings in a large cohort demonstrating a significantly increased prevalence of cavum septum pellucidum among fighters. Although cerebral microhemorrhages were higher in fighters than in controls, this finding was not statistically significant, possibly partially due to underpowering of the study.

Longitudinal MRI and cognitive change in Professional Fighters (P6.166)

Longitudinal MRI and cognitive change in Professional Fighters (P6.166)

Lack of Influence of Apolipoprotein E Status on Cognition or Brain Structure in Professional Fighters.

The role of the apolipoprotein e4 allele in moderating cognitive and neuroanatomical degeneration following repeated traumatic brain injury is controversial. Here we sought to establish the presence or absence of such a moderating relationship in a prospective study of active and retired boxers and mixed martial arts fighters. Fighters (n = 193) underwent cognitive evaluations, interviews regarding fight history, MRI of the brain, and genetic testing. We used a series of moderator analyses to test for any relationship of apolipoprotein genotype on structural volumes of brain regions previously established to be smaller in those with the most fight exposure, and on cognitive abilities also established to be sensitive to fight exposure. No moderating relationship was detected in any of the analyses. The results of this study suggest that there is no impact of apolipoprotein genotype on the apparent negative association between exposure to professional fighting and brain structure volume or aspects of cognition.

Biochemical Differences Between Official and Simulated Mixed Martial Arts (MMA) Matches.

BackgroundOne of the goals for training in combat sports is to mimic real situations. For mixed martial arts (MMA), simulated sparring matches are a frequent component during training, but a there is a lack of knowledge considering the differences in sparring and competitive environments.ObjectivesThe main objective of this study was to compare biochemical responses to sparring and official MMA matches.Materials and MethodsTwenty five male professional MMA fighters were evaluated during official events (OFF = 12) and simulated matches (SIM = 13). For both situations, blood samples were taken before (PRE) and immediately after (POST) matches. For statistical analysis, two-way analysis of variance (time x group and time x winner) were used to compare the dependent parametric variables. For non-parametric data, the Kruskal-Wallis test was used and differences were confirmed by Mann-Whitney tests.ResultsNo significant differences were observed among the groups for demographic variables. The athletes were 26.5 ± 5 years with 80 ± 10 kg, 1.74 ± 0.05 m and had 39.4 ± 25 months of training experience. Primary results indicated higher blood glucose concentration prior to fights for OFF group (OFF= 6.1 ± 1.2 mmol/L and SIM= 4.4 ± 0.7 mmol/L; P < 0.01) and higher ALT values for OFF group at both time points (OFF: PRE = 41.2 ± 12 U/L, POST = 44.2 ± 14.1 U/L; SIM: PRE = 28.1 ± 13.8 U/L, POST = 30.5 ± 12.5 U/L; P = 0.001). In addition, the blood lactate showed similar responses for both groups (OFF: PRE= 4 [3.4 - 4.4] mmol/L, POST= 16.9 [13.8 - 23.5] mmol/L; SIM: PRE = 3.8 [2.8 - 5.5] mmol/L, POST= 16.8 [12.3 - 19.2] mmol/L; P < 0.001).ConclusionsIn conclusion, MMA official and simulated matches induce similar high intensity glycolytic demands and minimal changes to biochemical markers of muscle damage immediately following the fights. Glycolytic availability prior to the fights was raised exclusively in response to official matches.

Cognitive and Balance Correlates of Exposure and Brain Health in Professional Fighters (P3.314)

Cognitive and Balance Correlates of Exposure and Brain Health in Professional Fighters (P3.314)

Predicting Cognitive Impairment in Professional Fighters (P3.342)

Predicting Cognitive Impairment in Professional Fighters (P3.342)

Salivary nitrite content, cognition and power in Mixed Martial Arts fighters after rapid weight loss: a case study

Rapid weight loss (RWL) is extensively practiced by combat sports athletes, including Mixed Martial Arts (MMA), but its effects on performance are not well established with different magnitudes of RWL, including those higher than 5% of total body weight. The aim of the present study was to follow MMA athletes during RWL with subsequent weight regain to evaluate the responses of isometric strength, power, cognition and salivary nitrite ( ) content. Two professional male MMA fighters, same age, competing in the same weight category underwent two magnitudes of RWL before a simulated competition period. Anthropometric measures, records of nutritional status, training, voluntary dehydration strategies, salivary samples, cognition response, isometric strength and muscular power were obtained: (I) 7 days before combat, (II) at the weigh-in moment, and (III) in the combat day. Athlete 1 lost 7.2 kg (9.1% of total bodyweight) and Athlete 2 lost 4.0 kg (5.3% of total bodyweight). Athlete 1 had a lower and misbalanced caloric ingestion (708 ± 428 kcal), ingested 6 L of water during the first 5 days of RWL, underwent 2 days of fasting, water and sodium restriction before weigh-in. Athlete 2 was supervised by a nutritionist, had a balanced diet (1600 ± 0 kcal), ingested 2 L of water during the first 6 days of RWL, underwent only 1 day of fasting and water restriction, and did not restrict sodium. As expected, there was a negative effect of RWL in the evaluated parameters at the weigh-in moment, while in the combat day, salivary ) content. Two professional male MMA fighters, same age, competing in the same weight category underwent two magnitudes of RWL before a simulated competition period. Anthropometric measures, records of nutritional status, training, voluntary dehydration strategies, salivary samples, cognition response, isometric strength and muscular power were obtained: (I) 7 days before combat, (II) at the weigh-in moment, and (III) in the combat day. Athlete 1 lost 7.2 kg (9.1% of total bodyweight) and Athlete 2 lost 4.0 kg (5.3% of total bodyweight). Athlete 1 had a lower and misbalanced caloric ingestion (708 ± 428 kcal), ingested 6 L of water during the first 5 days of RWL, underwent 2 days of fasting, water and sodium restriction before weigh-in. Athlete 2 was supervised by a nutritionist, had a balanced diet (1600 ± 0 kcal), ingested 2 L of water during the first 6 days of RWL, underwent only 1 day of fasting and water restriction, and did not restrict sodium. As expected, there was a negative effect of RWL in the evaluated parameters at the weigh-in moment, while in the combat day, salivary was not completely reestablished at baseline levels (decreased by 35.9% in Athlete 1 and, 25.2% in Athlete 2, as compared with 7 days before). The athlete who underwent a lower weight loss (5.3%) presented better recovery of cognition and upper limbs power on the combat day as compared with the athlete who lost 9.1% of body weight. Although we cannot precisely conclude, this case report led us to believe that the recovery period between weigh-in and competition may be insufficient for total reestablishment of salivary after RWL, and higher amounts of RWLhave negative impacts on average power and cognition when compared with lower RWL.Relevance for patients: Scientific aspects related with performance in MMA athletes brought to light the absence of studies investigating the recovery of isometric strength, power, cognition and salivary during RWL with subsequent weight regain. This study revealed that athletes from the same categories can adopt different magnitudes of weight loss, and that this procedure impacts several important measures, for example, the reduction of salivary is associated with the lower O2 transport capacity, decreasing muscle performance.

Injuries to Professional and Amateur Kickboxing Contestants: A 15-Year Retrospective Cohort Study.

Background:Kickboxing is a group of full-contact combat sports that allows both kicking and punching from a standing position. Despite its popularity, there is a scarcity of published data elucidating the injury epidemiology in kickboxing.Purpose:To determine the injury incidence, describe the injury pattern, and identify potential risk factors for injury in kickboxing.Study Design:Descriptive epidemiology study.Methods:Data describing fight outcomes and injuries sustained during professional and amateur kickboxing contests over a 15-year period were obtained from the official records of the Nevada Athletic Commission, United States. Injury incidence rates and rate ratios were calculated with 95% confidence intervals (95% CIs) per 1000 athlete-exposures (AEs) and per 1000 minutes of exposure. The injury pattern was described using frequencies and proportions of injuries by anatomic region and type of injury. In addition, Poisson mixed-effects generalized linear modeling was used to examine the multivariate relationships between injury incidence rates and potential risk factors.Results:The sample consisted of 481 unique fighters competing across 57 events, 976 AEs, 9562 minutes of exposure, and 380 injuries. The mean ± SD age of the fighters was 29.0 ± 5.3 years (range, 15-48 years). The overall injury incidence rates were 390.1 injuries (95% CI, 351.9-431.4) per 1000 AEs and 39.7 injuries (95% CI, 35.8-43.9) per 1000 minutes of exposure. The most commonly injured anatomic regions were the head (57.8%) and lower extremity (26.1%), while the most common types of injury were laceration (70.6%) and fracture (20.6%). Professional fighters were 2.5 times more likely to get injured compared with amateurs (rate ratio, 2.51; 95% CI, 1.39-4.55), while defeated fighters were 3.5 times more likely to get injured compared with winners (rate ratio, 3.48; 95% CI, 2.73-4.44).Conclusion:Injuries are frequent and often significant in kickboxing, and better injury surveillance is strongly recommended. The scarcity of good-quality epidemiological data in kickboxing, especially pertaining to the severity of injuries, underscores the urgent need for further research, whereupon evidence-informed sport safety and injury prevention policies can be developed.

Using automatic speech recognition to assess spoken responses to cognitive tests of semantic verbal fluency

Cognitive tests of verbal fluency (VF) consist of verbalizing as many words as possible in one minute that either start with a specific letter of the alphabet or belong to a specific semantic category. These tests are widely used in neurological, psychiatric, mental health, and school settings and their validity for clinical applications has been extensively demonstrated. However, VF tests are currently administered and scored manually making them too cumbersome to use, particularly for longitudinal cognitive monitoring in large populations. The objective of the current study was to determine if automatic speech recognition (ASR) could be used for computerized administration and scoring of VF tests. We examined established techniques for constraining language modeling to a predefined vocabulary from a specific semantic category (e.g., animals). We also experimented with post-processing ASR output with confidence scoring, as well as with using speaker adaptation to improve automated VF scoring. Audio responses to a VF task were collected from 38 novice and experienced professional fighters (boxing and mixed martial arts) participating in a longitudinal study of effects of repetitive head trauma on brain function. Word error rate, correlation with manual word count and distance from manual word count were used to compare ASR-based approaches to scoring to each other and to the manually scored reference standard. Our study’s results show that responses to the VF task contain a large number of extraneous utterances and noise that lead to relatively poor baseline ASR performance. However, we also found that speaker adaptation combined with confidence scoring significantly improves all three metrics and can enable use of ASR for reliable estimates of the traditional manual VF scores.