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Beetroot powder, a popular athletic supplement high in nitrates, purportedly enhances exercise performance. However, recent incidents during breath-hold swims in Air Force Special Warfare training, associated with beetroot powder use, raise safety concerns. Two cases of hypoxic events prompt discussion on interactions between beetroot supplementation and cardiovascular responses to breath-hold diving, suggesting a risk for blackout. Beetroot-induced vasodilation may counteract normal cardiovascular responses during swimming, emphasizing the need for further research to quantify risks. With inconsistent dosing and lack of standardized recommendations, heightened awareness of these risks is crucial for informed decision-making regarding beetroot supplements, especially in tactical athletes. [ABSTRACT FROM AUTHOR]

The purpose of this study was to analyze the association between hand grip strength (HGS) and pullup performance (PUP) in Royal Thai Army cadets (RTACs) and explore the associated factors. Twenty-six male RTACs volunteered to participate in this study. In a retrospective analytic design, measurements included HGS, body composition, relative onerepetition maximum lat pull (1RM Lat Pull·BW-1), repetitions to failure in lat pull at body weight load (Lat Pull at BW-load), and the pull-up test. Pearson's correlation was used to evaluate the relationships between variables with significance at P < 0.05. The results indicated that dominant HGS (HGS-D) exhibited a very large relationship (r = 0.712), while non-dominant HGS (HGS-ND) showed a large relationship (r = 0.593) with PUP. HGS-D, HGS-ND, and PUP also correlated significantly with percent body fat, 1RM Lat Pull·BW-1, and Lat Pull at BW-load (all, P < 0.01). This study contributes to a better understanding of the factors that influence PUP in RTACs and underscores the role of HGS in achieving success in pull-up tests. These findings emphasize the importance of incorporating grip strength training into physical fitness programs for military personnel to improve their overall physical readiness. [ABSTRACT FROM AUTHOR]

Firefighters work in a dangerous profession with high injury rates. Mobility dysfunction in firefighters may impact performance and contribute to injury. The Functional Movement Screen (FMS) is commonly used to evaluate individuals for mobility dysfunction and compensatory movements. The purpose of this study was to identify if mobility is related to firefighters' occupational task performance. This was a retrospective study assessing 29 career firefighters using FMS and occupational performance task scores. Statistical analyses consisted of a multiple linear regression assessing predictors on occupational task performance, and 21 point-biserial correlations ran to assess the relationship between each individual predictor and occupational task performance. Of the 21 point-biserial correlations, four were found to be significant, indicating a relationship between the FMS and occupational task performance. Inline Lunge L had a negative correlation with occupational task time and was statistically significant (rpb = -0.46, p = 0.012); Inline Lunge R had a negative correlation of moderate strength (rpb = -0.583, p = 0.001), Inline Lunge Combined had a negative correlation of moderate strength (rpb = -0.523, p = 0.004), and Shoulder Mobility L had a negative correlation of moderate strength (rpb = -0.445, p = 0.016). This study determined that the Inline Lunge component of the FMS may be a key element in occupational task performance. [ABSTRACT FROM AUTHOR]

This study compared an expert supervised, fully resourced physical training (PT) program compared to a traditional physical training PT plan on Army Officer Candidate School (OSC) soldier fitness outcomes. This retrospective cohort study compared 228 OCS soldiers (179 male [26.74±3.78 years] and 49 female [26.55±4.18 years]) in two companies for 12 weeks. One company participated in a fully resourced PT program designed by fitness experts to improve overall fitness and mobility (TAP-C). One company participated in traditional physical training designed to excel on the Army combat fitness test (ACFT, includes deadlift, power throw, push up, sprint-drag-carry, core strength, run) developed and led by OCS soldiers with standard resources. We assessed performance on the ACFT events, and grip strength, standing broad jump, overhead squat, and 90/90 switch assessment. Analysis of covariance was used to compare main effects of company on ACFT measures, controlling for covariates of pretest score differences and sex. Results included a significant effect of group on ACFT performance (N=228), F(1, 223) = 12.8, p<0.001 and on performance of five of the six ACFT events: MDL, F(1, 223) = 5.44, p = 0.021; HRP, F(1, 223) = 11.67, p < 0.001; SDC, F(1, 223) = 20.06, p < 0.001; LTK, F(1, 223) = 16.95, p < 0.001; and 2MR, F(1, 223) = 23.76, p < 0.001. The traditional company performed significantly better on ACFT muscular, anerobic and aerobic endurance focused events; the TAP-C company performed significantly better on muscular strength/explosive power events and mobility assessments. [ABSTRACT FROM AUTHOR]

Firefighters are required to perform a wide array of physically demanding job tasks, such as forcible entry, charged hose advances and victim extractions. An adequate level of muscular strength and power are required to successfully perform these tasks. The purpose of this study is to investigate the differences in stronger and weaker firefighters in measures of power. Archived data for twenty-seven (age = 34.3 ± 7.9 yr, body height = 176.3 ± 7.2 cm, body mass = 89.4 ± 15.7 kg) full-time firefighters were analyzed. Participants were placed into one of two groups [i.e., stronger (HIGH) (n = 13) and weaker (LOW) (n = 14)], based on their relative isometric mid-thigh pull (IMTPr) performance. Power measures included counter-movement jump (CMJ) height, and peak anaerobic power in watts (PAPW). Significant mean score differences were not discovered between HIGH and LOW IMTPr groups on any measures of lower-body power. Moderate positive correlations were observed between IMTP and CMJ (r = .519; p = .01). This study identified significant differences in absolute and relative strength between firefighters who were able to lift at least 2.0x their bodyweight versus those who were not. Additionally, absolute strength (as assessed by the IMTP) was significantly and positively correlated to CMJ height when compared to their weaker counterparts. These findings may provide insight into approaches for improving occupational performance and durability through the physical development of firefighters via strength and conditioning programs which focus on developing absolute strength, relative strength, and power. [ABSTRACT FROM AUTHOR]

Background Whereas ankle-foot injuries are ubiquitous and affect ~16% of military service-members, granularity of information pertaining to ankle sprain subgroups and associated variables is lacking. The purpose of this study was to characterize and contextualize the burden of ankle sprain injuries in the U.S. Military Health System. Methods This was a retrospective cohort study of beneficiaries seeking care for ankle sprains, utilizing data from the Military Health System Data Repository from 2009 to 2013. Diagnosis and procedural codes were used to identify and categorize ankle sprains as isolated lateral, isolated medial, concomitant medial/lateral, unspecified, or concomitant ankle sprain with a malleolar or fibular fracture. Patient characteristics, frequency of recurrence, operative cases, and injury-related healthcare costs were analyzed. Results Of 30,910 patients included, 68.4% were diagnosed with unspecified ankle sprains, 22.8% with concomitant fractures, (6.9%) with isolated lateral sprains, (1.7%) with isolated medial sprains and 0.3% with combined medial/lateral sprains. Pertaining to recurrence, 44.2% had at least one recurrence. Sprains with fractures were ~2-4 times more likely to have surgery within one year following injury (36.2% with fractures; 9.7% with unspecified sprains) and had the highest ankle-related downstream costs. Conclusion Fractures were a common comorbidity of ankle sprain (one in five injuries), and operative care occurred in 16.4% of cases. Recurrence in this cohort approximates the 40% previously reported in individuals with first-time ankle sprain who progress to chronic ankle instability. Future epidemiological studies should consider reporting on subcategories of ankle sprain injuries to provide a more granular assessment of the distribution of severity. [ABSTRACT FROM AUTHOR]

The purpose of this investigation was to evaluate the effects of foam rolling (FR) and passive recovery (PR) on symptoms of delayed-onset muscle soreness (DOMS) and military-specific performance. Twenty men and women (age: 23.6 ± 4.1 years, height: 176.4 ± 5.6 cm, and body mass: 84.7 ± 13.4 kg) completed a DOMS-inducing exercise protocol (DIP), followed by FR or PR. Four loaded military tasks (LMT) were performed 24 h later. Rating of perceived exertion (RPE) was measured during DIP and after each LMT. Rating of muscle pain (RMP) was measured prior to the LMTs and after the recovery protocols. A repeated measure analysis of variance and partial eta squared were used to compare LMT performance across baseline, FR and PR sessions. Friedman tests compared perceptual variables across baseline, FR, and PR. Wilcoxon matched-pairs signed-ranks test evaluated RPE during DIP, post-DIP, and post-recovery RMP between FR and PR. LMT performance times were significantly faster after FR compared to PR (stair climb: p =.038, cover position sprint: p =.011, simulated ammunition can carry: p =.003, Shuttle Run: p =.034). RPE measured during LMTs was similar across all data points. Post-recovery RMP for FR (3.0 (2.3, 4.0)) and PR (4.0 (3.0, 6.0)) were not significantly different. FR reduced the impact of DOMS on three loaded tactical performance tasks without significant reduction in perceived soreness. [ABSTRACT FROM AUTHOR]

Shoulder joint injuries are common for professional firefighters. A potential cause of shoulder injury is an imbalance between anterior (push) and posterior (pull) shoulder joint musculature. Understanding what contributes to these imbalances may help to identify areas needing improvement. The purpose of this study was to investigate different push to pull (P2P) ratios and the relationships among common upper body fitness assessments, body composition, and push to pull (P2P) ratios in firefighters. Thirty-three professional firefighters completed the following testing protocol: one-repetition maximum (1RM) bench press, pull-up repetitions to failure, push-up repetitions to failure, and a body composition assessment. The endurance P2P (eP2P) was computed by dividing the number of push-up by pull-up repetitions, while strength P2P (sP2P) was the relative 1RM divided by pull-up repetitions. Bivariate relationships among variables were assessed with correlation coefficients and linear regression assessed association between eP2P and sP2P (p ≤ 0.05). The sP2P and eP2P were not associated (R2 = 0.032, p = 0.99). Strength P2P was related with bench press 1RM (r = 0.80) and push-ups (r = 0.40). Endurance P2P was related with pull-up repetitions (r = -0.62), body fat percentage (r = 0.40), and fat mass index (r = 0.34). The results of the present study suggest sP2P and eP2P ratios should not be used interchangeably. To improve sP2P and eP2P for firefighters, it is recommended to improve the strength of anterior and posterior upper body musculature, respectively, and reduce total body fat mass. [ABSTRACT FROM AUTHOR]

This study measured the training load (TL) demands associated with a military-specific casualty drag measured via surface electromyography (sEMG) wearable technology, and the influence of sex and body mass on these measures. Thirty-six college-aged participants (males = 25; females = 11) performed two trials of a 123-kg (91-kg dummy with 32-kg load) backwards casualty drag over 15 m. Time was recorded to calculate drag velocity, with the fastest trial analyzed. Prior to testing, participants were fitted with compression garments embedded with sensors to measure the vastus lateralis and medialis (quadriceps; QUAD), biceps femoris (BF), and gluteus maximus (GM) of both legs. The sEMG signal for each muscle was measured as a percentage of maximal voluntary contraction to calculate TL. The variables included TL (total, QUAD, BF, GM), and between-muscle ratios. The sample was also ranked and median split via body mass into heavier and lighter groups. Independent samples t-tests calculated differences between drag velocity and TL for the sex and body mass groups. Pearson's correlations calculated relationships between body mass and velocity with the TL variables (combined, males, females). Females and lighter participants experienced greater TL compared to males and heavier participants, respectively (p < 0.01). A slower drag velocity correlated with a greater total and QUAD TL for all participants, males, and females (p ≤ 0.03, r = -0.65--0.80). Performing a slower casualty drag will increase TL demands, predominantly via QUAD stress. Training staff should develop the muscles important for the drag, especially for females and lighter males. [ABSTRACT FROM AUTHOR]

Background: Musculoskeletal injuries are recognized as the leading health problem and primary source of injury, disability, and financial burden across the military.1-5 Special Operations Forces are at an increased risk of musculoskeletal injury due to increased physical demands, precipitous deployments, and continual training and deployment cycles.6,4 Multiple injury screening tools exist, yet decisions to return to duty are frequently deferred to individual institutional protocol or provider clinical decision making, with no accepted gold standard.2,3,4,5 Purpose: The purpose of this case report is to describe the application of a system to return a Special Operations Forces candidate to duty following an ankle injury sustained during a military static line airborne operation while in the Special Forces Qualification Course. Case Description: The subject was a 34-year-old male with surgical fixation of a left distal fibular fracture with syndesmotic tear after landing from a static line airborne jump during the Special Forces Qualification Course. This case report provides a system to determine return to duty following an ankle fracture and provides a guide to returning a subject to participation, duty, and tactical performance training. Outcomes: Outcome measures recorded were vast, as the use of multiple measures are more indicative of overall function than any single measure. Impairment based measures included Global Rating of Change Scale (GROC), Numeric Pain Rating Scale (NPRS), lateral step down and Closed Chain Dorsiflexion (CCDF). Functional outcome measures included: the Functional Movement Screen™ (FMS™), Lower Quarter Y-Balance (LQYB), three hop tests for distance, and physical performance metrics. Discussion: The most substantial challenge to this process was the lack of standardized and validated military return to duty testing and guidelines in the literature. Ideally, pre-injury assessment would provide a baseline; however, compared to peers, the subject was well within acceptable ranges for all physical performance metrics at final Return to Duty testing. The subject was returned to duty 10 months after initial injury being physically comparable to his cohorts and being able to complete all military requirements. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the predictive value of the Triple Hop for Distance (THD) physical performance test to assess lower extremity (LE) strength and power in individuals donning firefighter personal protective equipment (PPE). Thirtyone healthy participants completed the THD in firefighter PPE on both the dominant and non-dominant limb. Dependent variables included LE power (vertical jump height [cm]) on a jump mat, and LE strength of the quadriceps and hamstrings (peak torque [Nm]) on an isokinetic dynamometer. THD was a strong predictor of LE power on the dominant (p<0.01) and non-dominant (p<0.01) limbs. THD was also a moderate predictor of LE strength on both the dominant limb (Ham60 [p<0.01]), Quad60 [p<0.01]), and the non-dominant limb (Ham60 [p<0.01]), (Quad60 [p<0.01]). The THD was found to be a strong and valid predictor for clinical measures of LE power and strength in firefighter PPE. [ABSTRACT FROM AUTHOR]

Musculoskeletal injuries are common in active duty firefighters. These injuries have significant medical and operational effects including increased prevalence of cardiovascular disease and excessive costs related to treatment and disability. The purpose of this study was to determine the impact of a comprehensive health, wellness, and safety initiative on overall fitness and injury prevalence in active duty firefighters. This retrospective analysis, collected data from firefighters (N=148) who participated in O2X training programs between September 2016 and March 2017. The training consisted of an initial lead-in week that included 40 hrs of lectures and supervised physical training followed by a periodized, tactical exercise training program. Demographics and performance scores from a battery of tests known as Key Performance Indicators (KPIs) were collected at baseline and at the end of each 16-wk program. The number of injuries contributing to paid time off, sick calls, salary and overtime costs, incidence of musculoskeletal injury, and incidence of disease were evaluated. KPIs improved in more than 89% of the population, depending on the fitness outcome. Overall cost savings was $6.3 million. The most impactful changes included a 19% reduction in monthly injuries and paid time off, 39% reduction in monthly sick calls, 33.3% reduction in costs related to Cardiac disease, 23.4% reduction in Cancer-related costs, and a 20% reduction in neck injury costs. These data demonstrate that the five principles of improvement established and reinforced by O2X are effective in instilling sustainable gains, functional fitness, and reducing injury in fire department personnel. [ABSTRACT FROM AUTHOR]

* BACKGROUND: Rates of lower extremity musculoskeletal injury are reportedly higher in professional and collegiate athletes following concussions. However, there is a paucity of evidence on this relationship in individuals who are not high-level athletes. * OBJECTIVES: To examine the risk of acute lower extremity musculoskeletal injury in soldiers within 2 years of an incident concussion, compared to matched nonconcussed soldiers. * METHODS: This was a matched-cohort study that used the medical encounter and personnel data of active-duty US Army soldiers from 2005 to 2011. Incident concussions were identified using International Classification of Diseases-Ninth Revision codes in medical encounter data of all soldiers from 2005 to 2009. One nonconcussed soldier in the US Army during the same month was matched by age, sex, rank, length of service, deployment status, and military career field to each concussed soldier. Hazard ratio (HR) and 95% confidence interval (CI) were calculated for the risk of lower extremity injury within 2 years of the incident concussion. Monthly HRs were compared to identify differences in injury rates between the groups, and an HR for the period of greatest difference was also calculated. * RESULTS: A total of 23 044 individuals (11 522 concussed and 11 522 nonconcussed) were included in the study. Within 2 years of concussion, the hazard of lower extremity injury was 38% greater in concussed compared to nonconcussed soldiers (HR, 1.38; 95% CI: 1.30, 1.46), while the 15-month hazard was 45% greater (HR, 1.45; 95% CI: 1.36, 1.56). * CONCLUSION: The rate of lower extremity musculoskeletal injury among this population of physically active adults is higher following concussion, and the risk remains elevated for more than a year following injury. [ABSTRACT FROM AUTHOR]

Background: Military organizations use movement quality screening for prediction of injury risk and performance potential. Currently, evidence of an association between movement quality and performance is limited. Recent work has demonstrated that external loading strengthens the relationship between movement screens and performance outcomes. Such loading may therefore steer us toward robust implementations of movement quality screens while maintaining their appeal as cost effective, field-expedient tools. Purpose: The purpose of the current study was to quantify the effect of external load-bearing on the relationship between clinically rated movement quality and tactical performance outcomes while addressing the noted limitations. Study Design: Crossover Trial. Methods: Fifty young adults (25 male, 25 female, 22.98±3.09 years, 171.95±11.46 cm, 71.77±14.03 kg) completed the Functional Movement Screen™ with (FMS™W) and without (FMS™C) a weight vest in randomized order. Following FMS™ testing, criterion measures of tactical performance were administered, including agility T-Tests, sprints, a 400- meter run, the Mobility for Battle (MOB) course, and a simulated casualty rescue. For each performance outcome, regression models were selected via group lasso with smoothed FMS™ item scores as candidate predictor variables. Results: For all outcomes, proportion of variance accounted for was greater in FMS™W (R² = 0.22 [T-Test], 0.29 [Sprint], 0.17 [400 meter], 0.29 [MOB], and 0.11 [casualty rescue]) than in FMS™C (R² = 0.00 [T-Tsst], 0.11 [Sprint], 0.00 [400 meter], 0.19 [MOB], and 0.00 [casualty rescue]). From the FMS™W condition, beneficial performance effects (p<0.05) were observed for Deep Squat (sprint, casualty rescue), Hurdle Step (T-Agility, 400 meter run), Inline Lunge (sprint, MOB), and Trunk Stability Push Up (all models). Similar effects for FMS™C item scores were limited to Trunk Stability Push Up (p<0.05, all models). Conclusions: The present study extends evidence supporting the validity of load-enhanced movement quality screening as a predictor of tactical performance ability. Future designs should seek to identify mechanisms explaining this effect. Level of Evidence: 3 [ABSTRACT FROM AUTHOR]

Summary Aim The aim of this study was to determine whether poor movement patterns impact on police recruit task performance. Methods Fifty-three volunteers were randomly selected from a pool of 173 police recruits attending basic recruit training. Relationships between movement performance, as measured by the Functional Movement Screen, and four occupational tasks were investigated. Results Eleven percent failed the marksmanship and baton strike assessments, 21% failed defensive tactics and 36% failed the tactical options assessment. Mean Functional Movement Screen score was 13.96 points (±1.99 points). Only the tactical options assessment approached a significant difference (p = 0.077) between pass/fail recruits. When Functional Movement Screen scores when graded as pass (14+) or fail (<14) again only the tactical options assessment approached significance ( p = 0.057). Conclusion The results of this study suggest that a relationship between an officer's movement patterns and occupational performance, most notably choice of tactical options, may exist. [ABSTRACT FROM AUTHOR]