Tactical Populations Research Articles

Modeling Risk for Lower Extremity Musculoskeletal Injury in U.S. Military Academy Cadet Basic Training.

Sport and tactical populations are often impacted by musculoskeletal injury. Many publications have highlighted that risk is correlated with multiple variables. There do not appear to be existing studies that have evaluated a predetermined combination of risk factors that provide a pragmatic model for application in tactical and/or sports settings. To develop and test the predictive capability of multivariable risk models of lower extremity musculoskeletal injury during cadet basic training at the U.S.Military Academy. Cadets from the class of 2022 served as the study population. Sex and injury history were collected by questionnaire. Body Mass Index (BMI) and aerobic fitness were calculated during testing in the first week of training. Movement screening was performed using the Landing Error Scoring System during week 1 and cadence was collected using an accelerometer worn throughout initial training. Kaplan-Meier survival curves estimated group differences in time to the first musculoskeletal injury during training. Cox regression was used to estimate hazard ratios (HRs) and Akaike Information Criterion (AIC) was used to compare model fit. Cox modeling using HRs indicated that the following variables were associated with injury risk : Sex, history of injury, Landing Error Scoring System Score Category, and Physical Fitness Test (PT) Run Score. When controlling for sex and history of injury, amodel including aerobic fitness and BMI outperformed the model including movement screening risk and cadence (AIC: 1068.56 vs. 1074.11) and a model containing all variables that were significant in the univariable analysis was the most precise (AIC: 1063.68). In addition to variables typically collected in this tactical setting (Injury History, BMI, and aerobic fitness), the inclusion of kinematic testing appears to enhance the precision of the risk identification model and will likely continue to be included in screening cadets at greater risk.

Development of an Abbreviated Model for Predicting Functional Movement Screen Score Within Tactical Populations.

Thompson, MB, Johnson, QR, Lindsay, KG, and Dawes, JJ. Development of an abbreviated model for predicting functional movement screen score within tactical populations. J Strength Cond Res 38(3): 607-611, 2024-The Functional Movement Screen (FMS) is a tool commonly used to identify compensations when performing 7 specific movement patterns. Timely administration of the full FMS is largely dependent on the practitioner's familiarity and experience with the screening battery. When working in populations that are time-poor (i.e., tactical professionals), administration of the full movement pattern battery is not always feasible. The purpose of this study was to determine which, if any, combination of movement patterns that comprise the FMS could be used to predict total score on this screen among first responders. Functional Movement Screen scores for 99 male subjects (mean ± SD; age: 37.55 ± 9.83 years; height: 180.38 ± 6.59 cm; and body mass: 97.87 ± 15.32 kg) and 9 female subjects (age: 33.22 ± 3.99 years; height: 172.11 ± 8.19 cm; and body mass: 83.99 ± 14.09 kg) from a single law enforcement and fire agency were used for this analysis. Subjects performed the full FMS, which consisted of the following movement patterns: deep squat (DS), hurdle step (HS), in-line lunge (ILL), shoulder mobility (SM), active straight leg raise (ASLR), trunk stability push-up (PU), and rotary stability (RS). A stepwise regression was used to determine the best predictors of the FMS 7-pattern model based on the model's R2. Cronbach's alpha and Guttman's lambda-2 were used to determine the reliability of the proposed models. The regression indicated that a 4-pattern model consisting of DS, ILL, SM, and PU was sufficient to predict approximately 84% of the full model (adjusted R2 = 0.84, p ≤ 0.001). This 4-pattern model was shown to be reliable with the 7-pattern model (α = 0.93, λ = 0.93). Using this modified version of the FMS may allow practitioners working in tactical populations a time-efficient method of identifying dysfunctional movement and determine whether the full 7-pattern model of the FMS should be considered.

Metabolic Costs of Walking with Weighted Vests.

The US Army Load Carriage Decision Aid (LCDA) metabolic model is used by militaries across the globe and is intended to predict physiological responses, specifically metabolic costs, in a wide range of dismounted warfighter operations. However, the LCDA has yet to be adapted for vest-borne load carriage, which is commonplace in tactical populations, and differs in energetic costs to backpacking and other forms of load carriage. The purpose of this study is to develop and validate a metabolic model term that accurately estimates the effect of weighted vest loads on standing and walking metabolic rate for military mission-planning and general applications. Twenty healthy, physically active military-age adults (4 women, 16 men; age, 26 ± 8 yr old; height, 1.74 ± 0.09 m; body mass, 81 ± 16 kg) walked for 6 to 21 min with four levels of weighted vest loading (0 to 66% body mass) at up to 11 treadmill speeds (0.45 to 1.97 m·s -1 ). Using indirect calorimetry measurements, we derived a new model term for estimating metabolic rate when carrying vest-borne loads. Model estimates were evaluated internally by k -fold cross-validation and externally against 12 reference datasets (264 total participants). We tested if the 90% confidence interval of the mean paired difference was within equivalence limits equal to 10% of the measured walking metabolic rate. Estimation accuracy, precision, and level of agreement were also evaluated by the bias, standard deviation of paired differences, and concordance correlation coefficient (CCC), respectively. Metabolic rate estimates using the new weighted vest term were statistically equivalent ( P < 0.01) to measured values in the current study (bias, -0.01 ± 0.54 W·kg -1 ; CCC, 0.973) as well as from the 12 reference datasets (bias, -0.16 ± 0.59 W·kg -1 ; CCC, 0.963). The updated LCDA metabolic model calculates accurate predictions of metabolic rate when carrying heavy backpack and vest-borne loads. Tactical populations and recreational athletes that train with weighted vests can confidently use the simplified LCDA metabolic calculator provided as Supplemental Digital Content to estimate metabolic rates for work/rest guidance, training periodization, and nutritional interventions.

Isokinetic Shoulder Strength and its Associations to Injury in Tactical Populations: A Critical Review

Isokinetic Shoulder Strength and its Associations to Injury in Tactical Populations: A Critical Review

Psychophysiological Responses in Soldiers during Close Combat: Implications for Occupational Health and Fitness in Tactical Populations.

This study explores the psychophysiological responses and subjective exertion experiences of soldiers in simulated hand-to-hand combat, aligning these findings with established physiological benchmarks. Active military personnel were monitored for heart rate, blood lactate levels, subjective exertion, cortical arousal, and muscle strength during combat scenarios. The results showed significant increases in heart rate and blood lactate, indicating intense cardiovascular demands and a reliance on anaerobic energy systems. Contrary to these physiological changes, soldiers reported lower levels of exertion, suggesting a possible underestimation of physical effort or individual differences in perception and mental resilience to stress. Notably, a decrease in cortical arousal post-combat was observed, potentially signaling cognitive function deficits in decision-making and information processing in high-stress environments. This decline was more pronounced than typically seen in other high-stress situations, highlighting the unique cognitive demands of hand-to-hand combat. Additionally, an increase in muscle strength was noted, underscoring the physiological adaptations arising from intensive combat training. These findings provide valuable insights into the psychophysiological effects of hand-to-hand combat, emphasizing the complex interplay between physical exertion, cognitive function, and stress response in military contexts. The study underscores the need for comprehensive training strategies that address both physical and psychological aspects to enhance combat readiness and decision-making under stress.

Effect of Aging on Movement Quality in Australian Urban Firefighters.

Redshaw, AS, Carrick-Ranson, G, Bennett, H, Norton, KI, and Walker, A. Effect of aging on movement quality in Australian urban firefighters. J Strength Cond Res 37(11): e601-e608, 2023-Adequate levels of movement quality (MQ) are required to safely perform occupational tasks in physically demanding and hazardous professions such as firefighting. Although it is well established that MQ deteriorates with age in population studies, there is conflicting evidence in older tactical populations. This study sought to examine the relationship between age and MQ in Australian urban firefighters. The impact of physical activity, injury history, and body mass index on MQ were also explored. The MQ of 324 professional Australian urban firefighters was assessed using MovementSCREEN MQ assessment tool. Scores of whole-body MQ ranged from 35.3 to 82.6 (0-100 scale), with a mean score of 59.2 ± 10.0. There was a moderate, negative association between MQ and age (r = -0.500; p ≤ 0.001), with those older than 50 years of age having significantly lower scores of MQ than their younger counterparts (p ≤ 0.001). Secondary analysis found that higher body mass index (r = -0.285; p ≤ 0.001), lower habitual physical activity levels (r = 0.165; p ≤ 0.003), and the presence of any musculoskeletal injury in the previous 12 months (p = 0.016) had significant negative effects on composite MQ. Firefighters older than 50, obese, and engaging in low levels of physical activity should be considered a high priority for functional strength training interventions to maintain adequate MQ throughout their careers.

An Examination of Subjective and Objective Measures of Stress in Tactical Populations: A Scoping Review.

Persons working in tactical occupations are often exposed to high-stress situations. If this stress is to be measured, an understanding of the stress outcomes used in these occupations is needed. The aim of this review was to capture and critically appraise research investigating subjective and objective outcome measures of physiological stress in tactical occupations. Several literature databases (PubMed, EMBASE, EBsco) were searched using key search words and terms. Studies meeting inclusion criteria were critically evaluated and scored by two authors using the Joanne Briggs Institute (JBI) critical appraisal tool. Of 17,171 articles, 42 studies were retained. The Cohen's Kappa agreement between authors was 0.829 with a mean JBI Score of included studies of 8.1/9 ± 0.37 points. Multiple subjective and objective measures were assessed during a variety of high-stress tasks and environments across different occupations, including police officers, emergency service personnel, firefighters, and soldiers in the military. Common objective outcomes measures were heart rate, cortisol, and body temperature, and subjective measures were ratings of perceived exertion, and the Self Trait Anxiety Inventory. Often used in combination (i.e., subjective and objective), these outcome measures can be used to monitor stressors faced by tactical personnel undergoing on-the-job training.

P28-029-23 Perceptions of Preventable Cancer Burden in Tactical Populations: A Cross-Sectional Study

P28-029-23 Perceptions of Preventable Cancer Burden in Tactical Populations: A Cross-Sectional Study

Efficacy of Corrective Exercise on Improving Functional Movement within the Tactical Population: A Critically Appraised Topic

Police, fire, emergency medical services, and military personnel encompass a tactical population that is considered an emerging setting in athletic training.Due to the occupational demands within this demographic, these patients are experiencing musculoskeletal injuries and injuries that withhold them from career duties at an alarming rate. One of the main contributors to the incidence of musculoskeletal injury is a lack of functional movement.1-3 Incorporating corrective functional movement programs should be a primary goal in treating tactical populations.

The Relationship between Psychological Hardiness and Military Performance by Reservists: A Moderation Effect of Perceived Stress and Resilience.

The purpose of this study is to evaluate the effect of hardiness on the perceived military performance of reservists, i.e., young people who have full-time jobs in a civilian sector and perform military training as a part of their civic duty. We proposed the conceptual model with conditional indirect effects of the hardiness on personal military performance, where mediated moderation effects are observed from personality traits and variables important for military service: team cohesion, perceived stress, and psychological resilience. The final dataset was comprised of 384 self-reported paper-pencil questionnaires filled out by reserve soldiers, and PROCESS Macro 3.5 Model 7 and Model 14 were used for the analysis. The results revealed that perceived stress (Model 1) and psychological resilience (Model 2) have a statistically significant moderate mediating effect on the interlink between hardiness and performance when personality traits and team cohesion are taken into consideration. The change in R2 is statistically significant and explains how perceived stress and psychological resilience affect individuals. When psychological hardiness is low, the level of perceived stress has a statistically significant moderating effect, i.e., it reduces the effect of hardiness on performance. When comparing the effects of perceived stress and psychological resilience, the latter has a stronger moderating effect on performance. Specifically, the moderating effect of resilience was more evident in Model 2 (66.9% variance, r = 0.818) for the military performance of the reservists than the perceived stress in Model 1 (52.5% variance, r = 0.724). This means that resilience increases the accountability of Model 2 compared to Model 1 by 14.4%. We conclude that resilience training could statistically significantly increase the military performance of reserve soldiers as a tactical population.

An Intense Bout of Acute Aerobic Exercise, but Not a Carbohydrate Supplement, Improves Cognitive Task Performance in a Sample of Black, Indigenous, and People of Color (BIPOC) Student Athletes.

There are contradictory findings in the literature on whether an acute bout of aerobic exercise leads to a post-exercise improvement in cognitive function (CF). Moreover, participants used in the published literature are not representative of the racial make-up of sport or tactical populations. A randomized crossover design was incorporated, with participants randomly consuming water or a carbohydrate sports drink within the first 3 min of a graded maximal exercise test (GMET) conducted in a laboratory. Twelve self-identified African American participants, (seven males, five females, age = 21.42 ± 2.38 years, height = 174.94 ± 12.55 cm, mass = 82.45 ± 33.09 kg) completed both testing days. Participants completed the CF tests immediately pre- and post-GMET. CF was assessed with the Stroop color and word task (SCWT) and concentration task grid (CTG). Participants completed the GMET when they reported a score of 20 on the Borg ratings of perceived exertion scale. Time to complete the SCWT incongruent task (p < 0.001) and CTG performance (p < 0.001) significantly improved post-GMET in both conditions. VO2max was positively correlated with pre- and post-GMET SCWT performance. The findings of our study suggest that an acute bout of maximal exercise significantly improves CF. Additionally, cardiorespiratory fitness is positively associated with CF in our sample of student athletes from a historically Black college and university.

Physical Training Programs for Tactical Populations: Brief Systematic Review.

This review aims (i) to identify and analyze the physical training programs used for tactical personnel (TP) and (ii) to understand the effects of physical training programs on the health and fitness, and occupational performance of tactical personnel. A literature search used the keywords 'Physical Training Program', 'Police', 'Law Enforcement', and 'Firefighter'. A total of 23 studies out of 11.508 analyzed were included. All studies showed acceptable methodological quality in assessing physical fitness (PF), and training programs' effect sizes (Cohen's d) on PF attributes were calculated. The results showed that physical training programs (duration > four weeks) can improve (medium-to-large effects) (i) measures of physical fitness and (ii) performance in simulations of occupationally specific tasks. This review provides summary information (i) to help select (or adjust) physical training programs for TP and (ii) to clarify the effect of different occupational-specific training interventions on fitness measures and health-related parameters for TP.

Validation of Garmin and Polar Devices for Continuous Heart Rate Monitoring During Common Training Movements in Tactical Populations

ABSTRACT Heart rate samples (n = 4500–8000) from wearables were compared to electrocardiography during a steady-state ruck (Ruck-S), maximal effort ruck (Ruck-M), submaximal cycle (Cycle), and Tabata Circuit. One device was worn at each location (wrist: Polar Grit-X, Garmin Fenix 6; chest-straps: Polar H10, Garmin HRM-Pro; armband: Polar Verity). Comparisons were made via percent error (MAPE) ≤5%, Concordance Correlation Coefficient (CCC), and ordinary least product regressions (OLP). H10 demonstrated strong agreement for all movements (MAPE = 1.28–3.40%, CCC = 0.93–0.99). During Ruck-S, Ruck-M, and Cycle, HRM-Pro (MAPE = 1.96–3.73%, CCC = 0.95–0.99) and Verity (MAPE = 1.84–5.36%, CCC = 0.98–0.99) demonstrated strong agreement. Fenix-6 demonstrated low MAPE (4.23–5.44%) and moderate to strong CCC (0.76–0.96) for Ruck-S, Ruck-M, and Cycle, while Grit-X had poor agreement (MAPE = 8.49–16.45%; CCC = 0.24–0.78). Tabata Circuit had the worst disagreement for all devices. Overall, chest straps and armbands demonstrated the strongest agreement, and should be worn when precise heart rate training is necessary.

Risk factors for the development of glenohumeral dislocations in tactical populations: a systematic review

Background: Joint dislocation injuries involve the complete loss of contact between the articulating surfaces of bones or internal joint prostheses, while joint subluxations involve the partial loss of contact. These injuries are associated with considerable economic costs, healthcare utilisation, and losses in occupational performance and availability. Currently, available evidence indicates military populations experience shoulder dislocations at a rate that may be 20 times higher than that reported for the general population.

Justified Concerns? An Exploration of the Leg Tuck in a Tactical Population.

The leg tuck was replaced by the plank in the Army Combat Fitness Test, in part because it was felt it discriminated against women. There is limited leg tuck research, including between-sex comparisons and relationships with other fitness tests. This study investigated the leg tuck in a firefighter trainee population (274 males, 31 females). Archival fitness test data included: Illinois agility test (IAT); push-ups; pull-ups; leg tucks; multistage fitness test; 4.54 kg backwards overhead medicine ball throw (BOMBT); 10-repetition maximum deadlift; and 18 kg kettlebell farmer's carry over a 91.44 m course. Independent samples t-tests (p < 0.05) and effect sizes (d) compared the sexes. Partial correlations and stepwise regression (controlling for sex; p < 0.05) calculated relationships between the leg tuck with the other tests. Male trainees outperformed females in all tests (p ≤ 0.003). The largest difference was for the BOMBT (d = 2.59) not the leg tuck (d = 1.28). The strongest leg tuck relationships were with pull-ups (r = 0.790) and push-ups (r = 0.553). Sex, pull-ups, and push-ups predicted the leg tuck (r2 = 0.674). Approximately 80% of the females could complete one leg tuck, although female personnel may require specific strength and power training. Pulling strength may be a determining factor in leg tuck performance, which is likely not indicated by the plank.

Factorial and Construct Validity of Sit-Up Test of Different Durations to Assess Muscular Endurance of Police Students

Background: The number of completed sit-ups in a given period of time is a commonly used assessment to measure trunk endurance in tactical populations. This study investigated factorial and construct validity of three different durations of a sit-up test—30 s, 60 s, and 120 s; Methods: Anthropometric characteristics and sit-ups performed for 30, 60, and 120 s by101 (♂: n = 62 and ♀: n = 39) police students were assessed. A factorial analysis was used to determine if three test durations group together in one factor, correlation analysis determined whether the sit-up tests were associated with anthropometric measures and whether the three variations in the test duration correlated between each other, and the Fisher’s transformation determined whether these correlations differed significantly; Results: All three sit-up variations loaded together into one factor in both sexes, providing factorial validity for all three test durations. Anthropometrics were associated with sit-up tests lasting 30 s in males and 120 s in females. A sit-up test lasting 60 s correlated significantly stronger to 120 s than to the 30 s sit-up test; Conclusions: The 60 s sit-up test seems to have the highest construct validity, as it was not affected by anthropometrics, and it may be an optimal choice for its lower risk of lower back injuries. By applying the results of this study, agencies could reduce the bias that may occur during the sit-up test and reduce the risk of injury during physical fitness assessment.

Blood Pressure Responses in Firefighters: A Review.

Blood pressure (BP) responses are controlled by various factors and understanding how BP changes is important to occupational health. This paper presents a review of the literature that reports BP responses in the firefighter population. Hypertension is one of the main risk factors underlying the pathophysiology of cardiovascular disease (CVD), and cardiac incidents remain the leading cause of line-of-duty deaths in firefighters. Risk factors for line-of-duty deaths include obesity, previous or underlying heart disease, and hypertension. The occupation of firefighting is one of the most hazardous and dangerous jobs, yet over 50 % of firefighters are volunteers. Tactical operations and the hazardous nature of firefighting are exposures that influence stress responses and, therefore, affect BP. In fact, hypertension in firefighters often remains undocumented or undiagnosed. CVD risk and elevated BP in tactical populations, like firefighters, maybe a combination of physical and emotional stress due to the nature of the job. Cross-sectional studies have reported that firefighters have higher levels of BP and higher rates of hypertension compared to civilians. Interestingly, there is a limited amount of research that reports BP values before and after firefighting- related activities, and very few studies on interventional changes in BP. Here, we synthesize the literature on firefighting and provide a summary of the studies that report pre- and post- BP levels that relate to CVD risk factors, occupational factors, firefighting activities, and the data on exercise training and BP. More studies are needed that examine BP in firefighters and report on the changes in BP with occupational activities.

Examining the Usability of Workload Monitoring in Firefighter Recruits

Although workload monitoring is commonly used in athletic settings to mitigate injury risk, we are unaware of previous studies examining its feasibility among firefighters. Nineteen firefighter recruits completed a short online workload survey at the end of each training day (Monday-Friday) for 26 weeks during the academy. A modified System Usability Scale was provided at midtesting (3 months into the academy) and posttesting (end of the academy). The recruits perceived the survey to be user-friendly throughout the academy (83.6 ± 13.6). However, questions 1 (survey frequency) and 6 (survey consistency) decreased and increased from midtesting to posttesting, respectively. Adherence was overall poor, decreasing from midtesting to posttesting. Our findings suggest that workload monitoring is a user-friendly tool within tactical populations; however, future research should consider optimal survey frequency to enhance compliance.

Mental Qualities and Techniques in Tactical Populations: A Systematic Review

Although applied sport psychology services have traditionally been provided in athletic settings, there has been a trend toward a more general application across different performance domains and, in particular, with tactical populations (i.e., military, law enforcement, and firefighters). The purpose of the current study was to systematically review the existing research on mental qualities and techniques in tactical populations. A database search revealed 7,220 potentially relevant articles, which were screened by two independent reviewers based on predefined inclusion criteria. This systematic screening process helped to identify 49 articles for further analysis. The findings highlight the benefits of developing mental qualities and techniques among tactical populations, as they can help to nurture a range of positive cognitive, affective, and behavioral outcomes. Yet, this review also indicates gaps and limitations that need to be addressed in future research to gain a better understanding of the antecedents, mediators, and consequences of these psychological constructs.

The Ventilatory Effects Of Thoracic Load Carriage While Walking

Tactical occupations often require load carriage (LC) while completing tasks. PURPOSE: To investigate the ventilatory effects of thoracic LC while walking. METHODS: Eight men (age: 21.0 ± 0.5 yr; height: 180.1 ± 4.9 cm; mass: 87.9 ± 12.8 kg; body fat: 19.2 ± 7.0%) and eight women (age: 19.8 ± 0.7 yr; height: 164.1 ± 7.0 cm; mass: 64.0 ± 12.4 kg; body fat: 23.5 ± 7.2%) participated in the study. On separate days, each subject completed four 10 min walking trials on a motorized treadmill at a predetermined unloaded intensity equal to 4 METs. Testing sessions included an unloaded (UL) trial, which served as the control, and wearing a light load (LL; 24 lb = 10.9 kg), moderate load (ML; 48 lb = 21.8 kg) and heavy load (HL; 80 lb = 36.4 kg) weighted vest. The testing order of the weighted vest trials was determined by counterbalanced assignment. Vest weights were selected to approximate common gear of tactical populations: law enforcement (LL), firefighter (ML), and military personnel (HL). An average value from the last 2 min of exercise was calculated for minute ventilation (Ve), respiratory rate (RR), and tidal volume (Tv) for statistical analysis to be used in a 2 x 4 Mixed Model ANOVA for statistical comparison. RESULTS: LC had a significant effect on Ve (F (3,42) = 99.775, p < .001) and RR (F(1.930, 27.021) = 29.835, p < .001), but not Tv (F(3,42) = 1.584, p = .207). Gender had a significant effect on Ve (F(1, 14) = 10.311, p = .006), Tv (F(1, 14) = 48.107, p < .001) and RR (F(1, 14) = 16.955, p = .001). In all LC conditions, males had a higher Ve (UL = 23.9 ± 1.8, LL = 27.9 ± 3.3, ML = 32.1 ± 3.9, HL = 35.5 ± 2.2 l·min-1) than females (UL = 19.9 ± 3.2, LL = 22.4 ± 3.3, ML = 27.0 ± 5.0, HL = 32.3 ± 2.9 l·min-1), a higher Tv (UL = 1.6 ± 0.3, LL = 1.4 ± 0.2, ML = 1.5 ± 0.3, HL = 1.5 ± 0.1 L) than females (UL = 0.9 ± 0.1, LL = 0.9 ± 0.2, ML = 1.0 ± 0.2, HL = 0.9 ± 0.1 L), and a lower RR (UL = 15.9 ± 2.5, LL = 20.7 ± 4.0, ML = 22.6 ± 4.5, HL = 23.4 ± 2.4 breaths·min-1) than females (UL = 22.6 ± 3.2, LL = 26.9 ± 6.0, ML = 29.3 ± 7.6, HL = 35.9 ± 5.5 breaths·min-1). CONCLUSION: Walking under thoracic LC elicited an increase in Ve that was driven by an increased RR. It is possible the chest restriction of the vest decreased the ability to increase TV. Supported in part by LHU Faculty Professional Development funds.