Male Combat Research Articles

Observations of Male Combat in Alligator Snapping Turtles in Florida and Georgia

Combat has been described in captive but not in wild Macrochelys temminckii (Alligator Snapping Turtle). Combat may be seldom observed in the wild because of the habitats used by these highly aquatic, cryptic turtles. We report 1 observation of fighting in M. temminckii and 3 observations of fighting in M. suwanniensis (Suwannee Alligator Snapping Turtle) from Florida and Georgia. Combat involved wrestling and biting of heads and front feet, and it was usually accompanied by dramatic bubbling of the water surface from submerged turtles. Observations were made in September, October, and December, outside of the presumed courtship and mating season.

Male crayfish (Faxonius obscurus, Decapoda: Cambaridae) claws are longer and stronger yet comparable in shape during the reproductive season

Abstract Animal weapons are diverse and often exaggerated structures associated with sexual selection and male–male combat. Despite their diversity, our knowledge of these structures comes primarily from studies that focus on the size of the weapons and neglect other components, such as their shape or performance. Furthermore, weapons can exhibit species-level plasticity based on nutrition and other ecological variables, but few studies have documented seasonal variation in weapon plasticity. Here, we investigate how weapon size, shape and performance differ across adult male reproductive and non-reproductive Allegheny crayfish, Faxonius obscurus. Given that F. obscurus and other cambarid crayfishes exhibit cyclical moulting between reproductive and non-reproductive states, they provide an ideal system in which to investigate such questions. We found that claws of reproductive and non-reproductive male F. obscurus differ in all three weapon components we investigated; claws from reproductive males were longer, stronger and different in shape compared with claws from non-reproductive males. Wielding longer and stronger claws is likely to confer greater competitive success during the mating season, which demonstrates an unexplored pattern of seasonal weapon plasticity. We discuss these results considering our knowledge of the seasonality of weapon phenotypes and propose several avenues of future research using cambarid crayfish as a model system.

Neural valuation of rewards and punishments in posttraumatic stress disorder: a computational approach

Posttraumatic stress disorder (PTSD) is associated with changes in fear learning and decision-making, suggesting involvement of the brain’s valuation system. Here we investigate the neural mechanisms of subjective valuation of rewards and punishments in combat veterans. In a functional MRI study, male combat veterans with a wide range of posttrauma symptoms (N = 48, Clinician Administered PTSD Scale, CAPS-IV) made a series of choices between sure and uncertain monetary gains and losses. Activity in the ventromedial prefrontal cortex (vmPFC) during valuation of uncertain options was associated with PTSD symptoms, an effect which was consistent for gains and losses, and specifically driven by numbing symptoms. In an exploratory analysis, computational modeling of choice behavior was used to estimate the subjective value of each option. The neural encoding of subjective value varied as a function of symptoms. Most notably, veterans with PTSD exhibited enhanced representations of the saliency of gains and losses in the neural valuation system, especially in ventral striatum. These results suggest a link between the valuation system and the development and maintenance of PTSD, and demonstrate the significance of studying reward and punishment processing within subject.

Moral Injury as a Social Phenomenon: Looking at the Unique Relationship with System Justification

ABSTRACT Moral Injury (MI) and Posttraumatic Stress Disorder (PTSD) are potential outcomes following combat military service which exposes veterans to a range of potentially morally injurious events (PMIEs). Given the hypothesized social nature of MI symptoms, it was predicted that System Justification, the tendency to defend and justify systems, even when they may be disadvantageous, would be uniquely related to MI, compared to PTSD. A total of 146 male combat veterans filled in questionnaires relating to PMIEs (MIES), MI (EMIS-short), PTSD symptoms (PCL-5) and System Justification (GSJS). PMIEs (self, other and betrayal related) were all related to higher levels of MI. A parallel mediation model was conducted and demonstrated that PMIEs (self) were associated with higher levels of MI and PTSD symptoms and that MI symptoms mediated the relationship between PMIEs (self) and lower System Justification. There was no mediation effect of PTSD symptoms. This relationship was strongest when veterans did not perform reserve duty and thus were not affiliated with the military. The findings support the theory that MI symptomology, as opposed to PTSD symptomology, has a greater relationship with worldviews such as the relationship to societal systems and that this is greatest when transitioned to civilian life.

The Dark Triad and Professional Fighters: Destigmatizing Male Combat Athletes.

Personality characteristics have long been studied in relation to athletes and their performance. Of these, emotional self-regulation has been determined to be an important factor regarding outcomes for athletes. Various research has examined the Dark Triad (Machiavellianism, narcissism, and psychopathy) among other personality traits in athletes. However, little research has examined Dark Triad levels in combat sports professionals and their impact on their athletic performance. Since professional fighting athletes have been perceived as aggressive and impulsive, it is essential to examine the athletes' level of Dark Triad traits. The present exploratory study investigates the association of Dark Triad personality traits in professional fighters versus college-aged male non-fighters. Secondly, it aims to evaluate the relationship between Dark Triad traits and winning percentages in professional fights. The study used a sample of professional male fighters (n = 36) and college-aged non-fighters (n = 29). Participants completed measures examining emotional self-regulation, trait anxiety, sensation seeking, and Dark Triad personality traits. The results of our study showed no significant differences in Machiavellianism, psychopathy, and narcissism between our samples of professional fighters and college-aged nonfighters. The study also showed no significant correlations between winning percentages for professional fighters and Machiavellianism, psychopathy, or narcissism.

Framework for Accurate Classification of Self-Reported Stress From Multisession Functional MRI Data of Veterans With Posttraumatic Stress

Background: Posttraumatic stress disorder (PTSD) is a significant burden among combat Veterans returning from the wars in Iraq and Afghanistan. While empirically supported treatments have demonstrated reductions in PTSD symptomatology, there remains a need to improve treatment effectiveness. Functional magnetic resonance imaging (fMRI) neurofeedback has emerged as a possible treatment to ameliorate PTSD symptom severity. Virtual reality (VR) approaches have also shown promise in increasing treatment compliance and outcomes. To facilitate fMRI neurofeedback-associated therapies, it would be advantageous to accurately classify internal brain stress levels while Veterans are exposed to trauma-associated VR imagery. Methods: Across 2 sessions, we used fMRI to collect neural responses to trauma-associated VR-like stimuli among male combat Veterans with PTSD symptoms (N = 8). Veterans reported their self-perceived stress level on a scale from 1 to 8 every 15 s throughout the fMRI sessions. In our proposed framework, we precisely sample the fMRI data on cortical gray matter, blurring the data along the gray-matter manifold to reduce noise and dimensionality while preserving maximum neural information. Then, we independently applied 3 machine learning (ML) algorithms to this fMRI data collected across 2 sessions, separately for each Veteran, to build individualized ML models that predicted their internal brain states (self-reported stress responses). Results: We accurately classified the 8-class self-reported stress responses with a mean (± standard error) root mean square error of 0.6 (± 0.1) across all Veterans using the best ML approach. Conclusions: The findings demonstrate the predictive ability of ML algorithms applied to whole-brain cortical fMRI data collected during individual Veteran sessions. The framework we have developed to preprocess whole-brain cortical fMRI data and train ML models across sessions would provide a valuable tool to enable individualized real-time fMRI neurofeedback during VR-like exposure therapy for PTSD.

Surface Refractive Surgery Outcomes in Israeli Combat Pilots

Photorefractive keratectomy (PRK) has long been the method of choice for refractive surgery in pilots, and was FDA approved for U.S. Air Force aviators in 2000. We retrospectively reviewed the medical records of 16 male combat pilots (mean age 25.0 ± 5.5 years) who had undergone bilateral laser refractive surgery with surface ablation (alcohol-assisted PRK: 81.25%, transepithelial-PRK: 18.75%), and who had a mean baseline spherical equivalent (SE) of −2.1 ± 0.7 D in the right eye, and −2.0 ± 0.7 D in the left. The mean follow-up was 8.4 ± 6.6 months. On the last visit, the uncorrected visual acuity (UCVA) had improved from 0.75 ± 0.33 logMar to −0.02 ± 0.03 logMar (p < 0.001), and from 0.72 ± 0.36 logMar to −0.02 ± 0.05 logMar (p < 0.001), for the right and left eyes, respectively. The percentages of participants with a right eye UCVA of at least 0.0, −0.08, and −0.18 logMAR (6/6, 6/5, and 6/4 Snellen in meters) were 100%, 37.5%, and 6.2%, respectively, and for the left eye, 93.7%, 43.75%, and 6.2%, respectively. No complications occurred. This is the first study to assess refractive surgery outcomes in a cohort of Israeli combat pilots. Surface refractive surgery effectively improved UCVA and reduced spectacle reliance for the members of this visually demanding profession.

Establishment of a laboratory‐rearing technique for the rove beetle Anotylus amicus (Coleoptera: Staphylinidae) with investigations of its life cycle, behavior and morphological variations

AbstractRove beetles (Staphylinidae) are one of the largest families in Coleoptera. Although the ecological features of rove beetles are important subjects in terms of understanding their diversification processes, laboratory‐rearing studies have only been conducted for a few species to date. In this study, we established a continuous rearing method for Anotylus amicus (Bernhauer, 1923) (Staphylinidae: Oxytelinae) using bell cricket food. In addition, its life cycle, behavior and morphological variations were investigated using the rearing technique. The mean duration of egg, first, second and third instars, prepupa and pupa were 4.3, 4.0, 4.0, 7.8, 1.7 and 4.7 days at 24°C, respectively. Adults and larvae used substrate, food and excrement for nesting. Mate guarding by males and associated male–male combat were observed. Head width and body size sexually varied; most males were larger than females, but some were comparable to females. Many individuals possessed undeveloped short hindwings, while some, especially large females, had long ones. As A. amicus can be reared simply, have a fairly short generation period, and exhibit interesting behavioral and morphological characteristics, A. amicus is suitable for clarifying the ecological aspects of rove beetles.

Transcending self therapy: Four-session individual integrative cognitive-behavioral treatment: A case report.

Effective treatments for Substance Use Disorders (SUDs) are of critical importance, particularly among veterans. We present a successful application of Transcending Self Therapy: Four-Session Individual Integrative Cognitive Behavioral Treatment (Individual TST-I-CBT), that helped a male combat veteran with Alcohol Use Disorder, Severe, and PTSD enter recovery and reduce depressive symptoms. Session 1 focused on problem solving and behaviors; Session 2 centered on checking and changing thoughts; Session 3 emphasized behaviors, thoughts, and coping; and Session 4 consisted of review and finalizing the recovery plan. After the second Individual TST-I-CBT session, he was abstinent from alcohol use and remained abstinent throughout the remainder of treatment. At the end of treatment, his depressive symptoms declined substantially from pretreatment (from severe to low), his desire to stop using alcohol was 10/10, and his confidence in his ability to stop using alcohol was 10/10. He demonstrated personal growth and accomplishments throughout the course of treatment, such as improving his self-concept and relationships; living in accordance with his values; developing the passionate pursuit of being a productive member of society by holding a job; looking for a job; and taking steps to continue his education. Accordingly, he accomplished all of his identified treatment goals. This case suggests Individual TST-I-CBT is a potentially effective adjunctive treatment for SUD. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Manual Pressure Points Technique for Massive Hemorrhage Control—A Prospective Human Volunteer Study

Background While commonly thought to be effective for management of limb and junctional hemorrhage, the manual pressure points technique was excluded from leading prehospital guidelines over a decade ago following the publication of a single human-volunteers study presenting unfavorable results. This work aimed to re-assess the efficacy and feasibility of the femoral and supraclavicular pressure points technique for temporary hemorrhage control distal to the pressure point. Methods A prospective, non-randomized, human volunteer, controlled environment study. In the study 35 healthy male combat medics (age 21.1 ± 1.3 years) received brief training after which they were requested to apply pressure in the femoral and supraclavicular points in attempts to stop regional blood flow, measured distally by Doppler ultrasound. Success rates in achieving flow cessation in under 2 minutes, time required for achievement of flow cessation, and cumulative flow cessation duration within a 3-minute follow-up after initial success were measured. Results For the supraclavicular point, success rates were 97.1% with a mean time to success of 12.5 (±20.9) seconds, lasting for 76.2% (±23.7) of the follow-up time. For the femoral point, success rates were 100% with a mean time to success of 5.5 (±4.3) seconds, lasting for 98.7% (±3.8) of the follow-up time. Conclusions Manual pressure on the femoral and supraclavicular points is an applicable and efficient method for temporary hemorrhage control distal to the pressure point. As such, with additional study, this method may be considered for re-introduction to prehospital care guidelines and training programs.

Evaluation of the vestibular/ocular motor screening assessment in active combat sport athletes: an exploratory study

ABSTRACT Objective The first aim of this study was to compare the results of the vestibular/ocular motor screening (VOMS) in combat sport athletes with a healthy control population. Second, to explore differences between athletes with and without a concussion history. Third, to examine the relationship between VOMS and the Post-Concussion Symptom Scale (PCSS) in combat sport athletes. Participants Forty active male combat sport athletes and 40 healthy male control participants were recruited from 4 clubs and a University in Australia. Methods Participants completed the VOMS in a primary care physiotherapy clinic. Participants completed an injury questionnaire and the PCSS. Results An “abnormal” score in at least one subtest or near point convergence (NPC) was recorded in 45% of the combat group compared with 22.5% of the control group. All VOMS scores and NPC distance were greater in the combat group compared with control group (p < 0.05). The VOMS scores were found to be moderately positively correlated with the PCSS. There was no difference in VOMS between athletes with and without a history of concussion (p > 0.05). Conclusion VOMS scores differed between combat sport athletes and control participants. The PCSS may aid clinicians in identifying athletes who have underlying vestibular/oculomotor impairment.

Early social experience, rather than kinship affecting aggression in an egg parasitoid wasp, Anastatus disparis (Hymenoptera: Eupelmidae), that exhibits extreme male–male combat behaviour

Fighting behaviour is important for acquiring crucial resources and is widely observed in the animal kingdom. Based on the conflict consequence, fighting behaviour is usually classified into non-extreme and extreme fighting patterns. Numerous factors that influence aggression, such as resource value, resource-holding potential, kinship, and prior experience, have been extensively studied, resulting in the emergence of many important theories. To secure mating opportunities, males of the quasi-gregarious parasitoid, Anastatus disparis (Hymenoptera: Eupelmidae), exhibit extreme fighting behaviour. Inconsistent with the general kin selection theory prediction, there is no evidence that male A. disparis competitors alter their fighting behaviour in response to relatedness with resource presence or interacted with altering resource value. The results of our current study do not clearly indicate whether unchanged kin-based aggression is caused by a lack of kin recognition ability or overriding by competition for resources, which A. disparis males rarely exhibit fighting behaviour under condition of resource female absence in the environment. However, significant decreases in the fighting frequency and intensity in A. disparis were shown in males with early social experience, which was also not influenced by the kinship between the contestants. Our result suggests that in A. disparis, male aggression was likely mediated by early social experience rather than kinship.

Body size and canine size do not confer a competitive advantage in male rhesus macaques

Male armaments are hypothesized to have evolved under intrasexual selection. Such traits may function as signals, weapons, or both, in male–male mating competition. Primate sexually dimorphic canine teeth and body size are two potentially weaponized traits whose function as a signal and/or weapon remains unclear, largely due to the difficulty of collecting detailed measurements of morphology on large free-ranging mammals. Rhesus macaques, Macaca mulatta, are an interesting study system in which to investigate how such traits function because they experience relatively low levels of direct male–male mating competition compared to other members of their subfamily. Furthermore, male dominance rank is largely based on a queuing system rather than on the outcome of intermale aggressive encounters. We leveraged a novel data set of behavioural observations and morphometric data from free-ranging rhesus macaques to investigate the function of sexually dimorphic canine teeth and body mass as weapons and/or signals. We tested whether canine height or body mass was correlated with dominance rank, whether similarity in any of these factors influenced the occurrence or outcome of agonistic interactions between male–male dyads and whether either of these traits predicted the likelihood of winning an agonistic interaction. Neither canine height nor body mass was related to dominance rank. Similarity in dominance rank, but not in morphology, predicted the occurrence of agonism between dyads. Agonistic encounters between males more similar in dominance rank were more likely to be characterized by aggression rather than submission. Dominance rank, but not canine height or body mass, predicted the likelihood of winning an agonistic interaction. Our results suggest that canine height and body mass do not confer a strong competitive advantage in male rhesus macaques and add to a growing body of evidence indicating that weaponized traits do not always seem to function either in fights or as signals in male–male combat.

Posttraumatic Stress Symptoms and Parenting Competence among Israeli Male Veterans: The Mediating Roles of Experiential Avoidance and Parental Reflective Functioning.

Although empirical studies have documented associations between posttraumatic stress symptoms (PTSS) and parenting among various high-risk populations, there is a relatively limited amount of research on paternal parenting among veterans. Moreover, the understanding of possible mechanisms which may account for this effect is severely lacking. This study examined associations between military related PTSS and parenting sense of competence (PSOC) among veteran fathers. Furthermore, we examined the mediating role of experiential avoidance (EA) and parental reflective functioning (PRF) in the association between PTSS and PSOC. Participants were 189 Israel Defense Forces (IDF) male combat veterans (mean age = 30.03) who completed a set of validated self-report questionnaires in a cross-sectional design study. Results showed negative associations between PTSS and PSOC-parental satisfaction but not parental efficacy. Furthermore, EA mediated the association between PTSS and parental satisfaction and efficacy; PRF- Pre mentalizing modes mediated the association between PTSS and parental satisfaction. Our findings imply that EA and PRF may serve as mechanisms of the association between PTSS and PSOC among veteran fathers. These findings are discussed in light of a psychological trauma perspective, and clinical implications to increase fathers’ mentalization and psychological flexibility are suggested.

Long horns protect Hestina japonica butterfly larvae from their natural enemies

Animals sometimes have prominent projections on or near their heads serving diverse functions such as male combat, mate attraction, digging, capturing prey, sensing or defence against predators. Some butterfly larvae possess a pair of long frontal projections; however, the function of those projections is not well known. Hestina japonica butterfly larvae have a pair of long hard projections on their heads (i.e., horns). Here we hypothesized that they use these horns to protect themselves from natural enemies (i.e., predators and parasitoids). Field surveys revealed that the primary natural enemies of H. japonica larvae were Polistes wasps. Cage experiments revealed that larvae with horns intact and larvae with horns removed and fitted with horns of other individuals succeeded in defending themselves against attacks of Polistes wasps significantly more often than larvae with horns removed. We discuss that the horns counter the paper wasps’ hunting strategy of first biting the larvae’s ‘necks’ and note that horns evolved repeatedly only within the Nymphalidae in a phylogeny of the Lepidoptera. This is the first demonstration that arthropods use head projections for physical defence against predators.

Vestibular and oculomotor function in male combat sport athletes

ObjectivesTo investigate for differences in vestibulo-ocular function between active male combat sport athletes and a healthy control group. In addition, to explore the relationship between symptom-based outcome measures with vestibulo-ocular function. DesignCross-sectional. Methods40 male adult combat sport athletes and 40 active male control participants were recruited from 4 martial arts schools and a University campus in Queensland, Australia. All participants completed a standardised protocol which was used to assess vestibulo-ocular function. The protocol included 3 components: 1) oculomotor function, 2) benign paroxysmal positional vertigo screening, and 3) vestibulo-ocular reflex function. The Post-Concussion Symptom Scale, Vestibular/Ocular Motor Screening tool and Dizziness Handicap Inventory were used as symptom-based outcome measures. ResultsMore combat sport athletes had oculomotor abnormalities than control group participants. There were no between group differences in benign paroxysmal positional vertigo, vestibulo-ocular reflex function and the video-head impulse test gain (ms). Combat sport athletes had higher symptom-based outcome scores. The Vestibular/Ocular Motor Screening tool and Dizziness Handicap Inventory were found to have moderate positive relationships with the total number of abnormalities detected in the combat sport group. ConclusionsVestibulo-ocular function is imperative for combat sport athletes to perform evasive manoeuvres and land their own strikes. The present study findings may aid clinicians in the identification of combat sport athletes with underlying vestibulo-ocular dysfunction, prompting further investigation.

First report of male–male combat in free-ranging Amazonian Common Lanceheads (Bothrops atrox)

In many snakes, males engage in agonistic interactions (male–male combat) apparently to establish dominant–subordinate relationships to gain priority access to reproductive females. In the Neotropical genus Bothrops Wagler, 1824 (∼45 species), male–male combat has been recorded only in three species of the monophyletic Bothrops atrox group. However, most male combats recorded in this clade occurred in captivity, an environment that facilitates the emergence of agonistic interactions. Here, we provide the first record of male–male combat in free-ranging Amazonian Common Lanceheads (Bothrops atrox (Linnaeus, 1758)) and discuss the implications of this observation for the species mating system. During fieldwork, we found one immature female and five active adult males, two of them fighting. These observations suggest that reproductive male B. atrox actively search and compete for widely dispersed and scarce receptive females.

Agonistic and mating behaviour of the endemic lizard Trachylepis atlantica from the Fernando de Noronha archipelago, Brazil

The skink Trachylepis atlantica is endemic to the Fernando de Noronha archipelago. Although this species is abundant in the archipelago, it is increasingly threatened by invasive species, predation, and anthropic interference. However, little is known about its natural history. Here we report on territory use, male-male combat, and mating behaviour of freeranging T. atlantica. During the dry season, we observed two bouts of male combat and two copulations, which suggests some mating seasonality. In male combat, T. atlantica displays ritualised agonistic behaviour with escalated aggressiveness that include - i) visualisation, approaching or following, ii) visual display, iii) bite and body confrontation, and iv) dominance. Adult males were always alert to invaders within their territories. After combat, resident males showed scars on their heads resulting from agonistic encounters. During the two copulations, we observed courtship, immobilisation, and mating.

Abstract 9349: The Relationship Between Combat-related Traumatic Injury and Cardiometabolic Risk

Introduction: The relationship between combat-related traumatic injury (CRTI) and cardiovascular risk is uncertain. Available data are largely derived from small retrospective or cross sectional studies. Hypothesis: This study was designed to investigate, prospectively, the link between CRTI and both metabolic syndrome (MetS) and arterial stiffness Methods: From March 2016 to August 2020, 1144 male combat veterans (UK-Afghanistan War 2003-14) were recruited into the ADVANCE cohort; they comprised 579 men with CRTI and 565 uninjured participants frequency-matched for age, service, rank, regiment, deployment period and role-in-theatre. Investigations included quantification of injury severity (New Injury Severity Scale [NISS]), whole body composition (dual-energy X-ray absorptiometry), arterial stiffness (heart rate-adjusted central augmentation index [cAIx] and pulse wave velocity [PWV]), fasting venous blood glucose, lipids and high sensitivity C-reactive protein (hs-CRP). Insulin resistance was quantified using the estimated glucose disposal rate. The relationships of CRTI to MetS and cAIx were examined using modified Poisson and multiple linear regression analyses respectively. Results: The participants were aged 34·1±5·4 years, which was similar in the CRTI and uninjured groups; the mean time from injury or relevant deployment was 8·3±2·1 years. MetS prevalence (18·0% vs 11·8%; adjusted IRR 1·46; 1·10, 1·94) and cAIx (17·61±8·79 vs 15·23±8·19: p&lt;0·0001) were higher among the CRTI than uninjured group. Abdominal waist circumference, visceral fat area, triglycerides, insulin resistance and hs-CRP were higher and HDL-cholesterol lower with CRTI. There were no significant between-group differences in blood glucose, blood pressure or PWV. CRTI, its severity (↑NISS), lower age and socioeconomic status (SEC) were independently associated with both MetS and cAIx. Conclusions: CTRI is associated with an increased prevalence of MetS and arterial stiffness which are also influenced by age, injury severity and SEC. The longitudinal impact of CRTI on clinical cardiovascular events needs further examination

Achilles and patellar tendon structure following a prevention program in male combat soldiers

ABSTRACT Objectives The aims of the study were to compare the prevalence of soldiers with musculoskeletal symptoms between soldiers that participated in a prevention program (INT) and a control group (CONT); and, to assess whether ‘high risk’ for a symptom indicator [participants with patellar tendon (PT) echo-type III+IV >10% or Achilles tendon (AT) echo-type III >8.5%] applies when a prevention intervention is used. Methods Soldiers from two consecutive infantry commanders courses (year 1-CONT, n = 165; year 2-INT, n = 196) were examined pre-course for AT and PT structure using ultrasound tissue characterization (UTC), and their musculoskeletal overuse symptoms were assessed and recorded by military physicians throughout the course. A prevention program was provided to the INT group (year 2) during the 14-week course. Results No significant differences were found in the prevalence of soldiers with symptoms between the two groups [INT: 39 (19.9%), CONT: 40 (24.2%); p = .32]. Using the indicator at baseline, 20 soldiers (10.2%) were suggested to be at ‘high risk.’ Of those 20 soldiers, 17 actually had symptoms during the course (positive predictive value-85%). The prevalence of soldiers with a suggested ‘high risk’ according to our indicator who had no symptoms during the course was low (3/20, 15%). Twenty-two soldiers who had symptoms during the course had not been suggested to be at ‘high risk’ by our indicator. Conclusion Our intervention did not reduce the prevalence of soldiers with symptoms. Our ‘high risk’ pre-course, AT and PT structure indicator is valid and can be used as a screening tool to reduce the prevalence of symptoms in combat soldiers; with the caution that soldiers that were not identified by the indicator, might also have symptoms along the course.