Comparison of injuries between US Army paratroopers and their non-paratrooper soldier counterparts.

INTRODUCTION: Military studies have investigated acute injuries associated with parachute jumps, but the literature does not address paratroopers' cumulative microtraumatic (CMT) injury risk, nor does it compare injury risks between paratroopers and the rest of the military population. This study determined whether US active duty Army paratroopers experienced greater injury risks than their non-paratrooper soldier counterparts and whether their injuries cost more to treat suggesting greater injury severity. METHODS: This retrospective study evaluated electronic medical records (2016-2018) for 31 621 paratroopers and a randomly selected comparison group of 170 715 non-paratrooper soldiers. Analyses included univariate and multivariate regression to quantify odds of injuries associated with risk variables and additional descriptive statistics. RESULTS: Paratroopers had a 57% increase in the odds of experiencing one or more injuries (OR=1.57, 95% CI: 1.52 to 1.62) after controlling for sex, race and age, with a greater proportion of acute injuries (OR=1.38, 95% CI: 1.34 to 1.42), relative to comparison group soldiers. Injury types proportionally higher among paratroopers included head trauma and shoulder injuries. Average injury cost among paratroopers was 13% lower than for non-paratroopers ($2470 vs $2830 per injury). Among both populations, acute injury costs were notably higher than for CMT injuries (paratroopers, $1710/$630; non-paratroopers, $1860/$880 per injury). CONCLUSIONS: Paratroopers were more likely to incur injury, especially an acute injury, than non-paratroopers. However, paratroopers' average injury costs were less. This may be due to higher return-to-duty motivations, fitness levels, and/or facility-specific cost of care. Future studies should investigate causes of injuries found to be proportionally higher among paratroopers.

Pectoralis major injuries in the military: a surveillance approach to reduce an underestimated problem.

INTRODUCTION: Multiple studies report increasing cases of surgically treated pectoralis major (PM) muscle and tendon ruptures in military populations. Studies associate this with a growing popularity of weight-training and bench press exercises. Mild-to-moderate non-surgical PM traumas and overuse injuries have not been included in these studies despite evidence that these types of outpatient injuries account for the majority of the military's injury medical burden. METHODS: To assess rates of all PM injuries (ruptures, tears, strains, overuse), regardless of form of treatment, a PM injury surveillance definition was derived from International Classification of Disease (ICD) diagnostic codes used in routine US Army injury surveillance. A detailed clinical examination of 2016 Active Duty Army medical records was used to identify ICD codes commonly associated with PM injuries. Cost data were calculated and the definition applied to medical data from 2016 through 2018to assess trends. RESULTS: The estimated incidence of PM cases among soldiers was over 95% greater than if only considering severe surgical cases. Over 96% of army annual PM injury costs (direct medical and indirect from lost labour) were for outpatient services. PM injury incidence rates were not statistically different from 2016 to 2018. CONCLUSIONS: The PM injury surveillance definition provides a consistent means to monitor trends over time and evaluate the effectiveness of prevention efforts. PM injuries have a larger military impact than previously recognised and prioritised prevention strategies are needed to reduce them. Future interventions could focus on the bench press given its observed association with PM injuries.

The cost of lower extremity fractures among active duty U.S. Army soldiers, 2017.

The estimated cost to the Army for lower extremity fractures in 2017 was approximately $116 million. Direct medical expenses totaled $24 million, and indirect medical costs totaled $92 million ($900 thousand lost duty; $91 million limited duty). Foot and toe fractures, along with lower leg and ankle fractures accounted for the majority of soldiers' initial visits for care (n=4,482; 91.6%), and more than $103 million (89.0%) of overall costs ($116 million). Costs varied by location of care. In outpatient settings, initial visits for foot and toe injuries accounted for the highest costs: $49 million overall. Direct medical costs totaled $1.2 million, and indirect medical costs (limited duty) were $48 million. Conversely, in inpatient settings, lower leg and ankle fractures accounted for slightly more than half of all costs (overall $9 million; $4.8 million in direct medical costs and $4.5 million in indirect medical costs). The finding that the majority of costs related to lower extremity fractures were due to estimated days of lost or limited duty and associated loss of productivity justifies the inclusion of indirect cost estimates as a part of overall injury cost calculations.

The Impacts of ICD-10-CM on U.S. Army Injury Surveillance.

INTRODUCTION: Injuries are the leading cause of medical encounters and lost work days in the U.S. Army, affecting more than half of active-duty soldiers annually. Historically, Army injury surveillance has captured both acute traumatic and cumulative microtraumatic overuse injuries. This article describes how the transition from the ICD-9-CM to ICD-10-CM impacted U.S. military injury surveillance by comparing injury rates and distributions under both systems. METHODS: Mapping ICD-9-CM codes to the expanded ICD-10-CM codes is not a straightforward endeavor; therefore, the Army Public Health Center incorporated ICD-10-CM codes into a comprehensive, systematic approach to taxonomically categorize injuries. This taxonomic methodology was applied to Army injuries under ICD-10-CM (2016-2019) and compared with the ICD-9-CM Army injury surveillance definitions (2012-2015). RESULTS: Soldier injury rates appeared to increase when surveillance with ICD-10-CM began. Soldiers experienced 1,276 incident injury medical encounters per 1,000 person-years in 2015 (ICD-9-CM), compared with 1,804 injuries per 1,000 in 2016 (ICD-10-CM), a 41% increase. Importantly, the distribution of injuries also shifted, such that the average cumulative microtraumatic injury rate increased by 42% during 2016-2019 (ICD-10-CM) compared with the 2012-2015 average (ICD-9-CM), whereas acute traumatic injuries only increased by 17%. CONCLUSIONS: The enhanced descriptions provided by ICD-10-CM codes and the applied taxonomic categorizations have improved precision in Army injury surveillance. Data unequivocally show that most injuries in this physically active population are cumulative microtraumatic injuries. The taxonomic methodology can be extended to injury surveillance in other populations and may allow a more efficient transition to ICD-11-CM.

Using causal energy categories to report the distribution of injuries in an active population: An approach used by the U.S. Army.

OBJECTIVES: To describe the etiologic distribution of all injuries among U.S. Army Active Duty soldiers by causal energy categories. DESIGN: Retrospective cohort, descriptive analysis. METHODS: Injury was defined as the interruption of tissue function caused by an external energy transfer (mechanical, thermal, radiant, nuclear, chemical, or electrical energy). A comprehensive injury matrix standardized categories by causal energies, body locations, and injury types. Categories differentiated acute (ACT) from cumulative micro-traumatic (CMT) overuse injuries, and musculoskeletal injuries (MSKI) from those affecting other or multiple body systems (non-MSKI). International Classification of Diseases (ICD) diagnoses codes were organized into established categories. The matrix was applied to electronic health records for U.S. Army soldiers in 2017. RESULTS: Mechanical energy transfers caused most injuries (97%, n = 809,914): 76% were CMT overuse and the remaining were ACT (<21%). The majority (83%) were MSKI (71% CMT, 12% ACT). While almost one-half (47%) were to lower extremities (38% CMT, 9% ACT) the most frequently injured anatomical sites were the knee and lower back (16% each, primarily CMT). CONCLUSIONS: For the first time all soldiers' injuries have been presented in the same context for consistent comparisons. Findings confirm the vast majority of injuries in this physically-active population are MSKI, and most are CMT MSKI. A very small portion are non-MSKI or injuries caused by non-mechanical energy (e.g., heat- or cold-weather). Most Army injuries are to the lower extremities as a grouped body region, but additional matrix specificity indicates the most injured anatomical locations are the knee, lower back, and shoulder.

Musculoskeletal training injury prevention in the U.S. Army: Evolution of the science and the public health approach.

Injuries cause more morbidity among soldiers in the U.S. Army than any other health condition. Over two-thirds of U.S. soldiers' injuries occur gradually from cumulative micro-traumatic damage to the musculoskeletal system as a result of physical training activities. Paradoxically, the very physical training activities required to improve soldier performance also result in injury. Determining the amounts and types of physical training that maximize performance while minimizing injuries requires scientific evidence. This evidence must be incorporated into a framework that ensures scientific gaps are addressed and prevention efforts are evaluated. The five-step public health approach has proven to be an effective construct for Army public health to organize and build an injury prevention program. Steps include: 1) surveillance to define the magnitude of the problem, 2) research and field investigations to identify causes and risk factors, 3) intervention trials and systematic reviews to determine what works to address leading risk factors, 4) program and policy implementation to execute prevention, and 5) program evaluation to assess effectiveness. Dissemination is also needed to ensure availability of scientific lessons learned. Although the steps may not be conducted in order, the capability to perform each step is necessary to sustain a successful program and make progress toward injury control and prevention. As with many U.S. public health successes (e.g., seatbelts, smoking cessation), the full process can take decades. As described in this paper, the U.S. Army uses the public health approach to assure that, as the science evolves, it is translated into effective prevention.

The Etiology of Injuries in US Army Initial Entry Training.

BACKGROUND: US Army initial entry training (IET) trainees engage in intense physical activities for 10 or more weeks prior to their assignment to operational units. Many trainees succumb to injury during IET. Injuries to the lower extremities and back have historically been the most common, and thus have been the focus of routine health surveillance. OBJECTIVES: The primary goal of this analysis was to verify the training-related injuries of greatest concern and to update the clinical diagnostic codes (ICD-10-CM) used in surveillance. The investigation also aimed to develop a sense of the financial magnitude of these injuries. METHODS: The distribution of all IET injuries was determined using a comprehensive injury taxonomy. Injuries were categorized based on causal energy source (mechanical, thermal, radiant, nuclear, chemical, or electrical). Mechanical energy transfers included acute trauma and cumulative microtrauma ("overuse"). Injury ICD-10-CM codes were identified in calendar year 2016 IET trainees' electronic healthcare records. Injury frequencies were reported for gender, body region, and injury type. Costs were calculated from medical encounters and estimated lost training time using the most frequently injured anatomical site as a baseline. RESULTS: Among 106,367 trainees, 65,026 separate injuries were identified. Mechanical energy transfers to lower extremities caused 75% of all injuries; most (65%) were cumulative microtraumatic. The most frequently injured anatomical site (the knee, 20% of injuries), is estimated to have cost over $39 million. CONCLUSIONS: Lower extremity injuries, followed by those of the low back continue to be leading "training-related injuries". This suggests the need to ensure distances and/or frequencies of weight-bearing activities (running, foot-marching) are not increased too rapidly or too excessively, and that trainees' fitness prior to IET is adequate. Medical costs and lost training time should be included in future monitoring.

Risk factors for injury associated with low, moderate, and high mileage road marching in a U.S. Army infantry brigade.

OBJECTIVES: Road marching is an important physical training activity that prepares soldiers for a common occupational task. Continued exploration of risk factors for road marching-related injuries is needed. This analysis has assessed the association between modifiable characteristics of physical training and injury risk. METHODS: Injuries in the previous 6 months were captured by survey from 831 U.S. Army infantry soldiers. Road marching-related injuries were reported as those attributed to road marching on foot for specified distances while carrying equipment. Frequencies, means, and relative risk ratios (RR) for road marching-related injury with 95% confidence intervals (CI) were calculated. Adjusted odds ratios (OR) and 95% CI were calculated for leading risk factors using multivariable logistic regression. DESIGN: Retrospective cohort study. RESULTS: Half (50%) of reported injuries were attributed to road marching or running. When miles of exposure were considered, injury risk during road marching was higher than during running (RRroad marching/running=1.8, 95% CI: 1.38-2.37). A higher product of road marching distance and weight worn (pound-miles per month) resulted in greater injury risk (RR≥1473 pound-miles/<1472=1.92, 95% CI: 1.17-2.41). Road marching-related injuries were associated with carrying a load >25% of one's body weight (OR>25%/1-20%=2.09, 95% CI: 1.08-4.05), having high occupational lifting demands (OR50-100+lbs/25-50lbs=3.43, 95% CI: 1.50-7.85), road marching ≥5 times per month (OR≥5 times/4 times=2.11, 95% CI: 1.14-3.91), and running <4 miles per week during personal physical training (OR0/≥10 miles/week=3.56, 95% CI: 1.49-8.54, OR1-4/≥10 miles/week=4.14, 95% CI: 1.85-9.25). CONCLUSIONS: Ideally, attempts should be made to decrease the percentage of body weight carried to reduce road marching-related injuries. Since this is not always operationally feasible, reducing the cumulative overloading from both physical training and occupational tasks may help prevent injury.

Impact of physical fitness and body composition on injury risk among active young adults: A study of Army trainees.

OBJECTIVES: To determine the combined effects of physical fitness and body composition on risk of training-related musculoskeletal injuries among Army trainees. DESIGN: Retrospective cohort study. METHODS: Rosters of soldiers entering Army basic combat training (BCT) from 2010 to 2012 were linked with data from multiple sources for age, sex, physical fitness (heights, weights (mass), body mass index (BMI), 2 mile run times, push-ups), and medical injury diagnoses. Analyses included descriptive means and standard deviations, comparative t-tests, risks of injury, and relative risks (RR) and 95% confidence intervals (CI). Fitness and BMI were divided into quintiles (groups of 20%) and stratified for chi-square (χ2) comparisons and to determine trends. RESULTS: Data were obtained for 143,398 men and 41,727 women. As run times became slower, injury risks increased steadily (men=9.8-24.3%, women=26.5-56.0%; χ2 trends (p<0.00001)). For both genders, the relationship of BMI to injury risk was bimodal, with the lowest risk in the average BMI group (middle quintile). Injury risks were highest in the slowest groups with lowest BMIs (male trainees=26.5%; female trainees=63.1%). Compared to lowest risk group (average BMI with fastest run-times), RRs were significant (male trainees=8.5%; RR 3.1, CI: 2.8-3.4; female trainees=24.6%; RR 2.6, CI: 2.3-2.8). Trainees with the lowest BMIs exhibited highest injury risks for both genders and across all fitness levels. CONCLUSIONS: While the most aerobically fit Army trainees experience lower risk of training-related injury, at any given aerobic fitness level those with the lowest BMIs are at highest risk. This has implications for recruitment and retention fitness standards.

Fitness tests and occupational tasks of military interest: a systematic review of correlations.

: Physically demanding occupations (ie, military, firefighter, law enforcement) often use fitness tests for job selection or retention. Despite numerous individual studies, the relationship of these tests to job performance is not always clear. : This review examined the relationship by aggregating previously reported correlations between different fitness tests and common occupational tasks. : Search criteria were applied to PUBMED, EBSCO, EMBASE and military sources; scoring yielded 27 original studies providing 533 Pearson correlation coefficients (r) between fitness tests and 12 common physical job task categories. Fitness tests were grouped into predominant health-related fitness components and body regions: cardiorespiratory endurance (CRe); upper body, lower body and trunk muscular strength and muscular endurance (UBs, LBs, TRs, UBe, LBe, TRe) and flexibility (FLX). Meta-analyses provided pooled r's between each fitness component and task category. : The CRe tests had the strongest pooled correlations with most tasks (eight pooled r values 0.80-0.52). Next were LBs (six pooled r values >0.50) and UBe (four pooled r values >0.50). UBs and LBe correlated strongly to three tasks. TRs, TRe and FLX did not strongly correlate to tasks. : Employers can maximise the relevancy of assessing workforce health by using fitness tests with strong correlations between fitness components and job performance, especially those that are also indicators for injury risk. Potentially useful field-expedient tests include timed-runs (CRe), jump tests (LBs) and push-ups (UBe). Impacts of gender and physiological characteristics (eg, lean body mass) should be considered in future study and when implementing tests.

Identification of specific activities associated with fall-related injuries, active component, U.S. Army, 2011.

Although falls continue to be a leading mechanism of serious injuries among military populations, interventions must target activities or hazards that can be controlled or managed. This project aimed to identify activities most frequently associated with Army soldier fall-related injuries to prioritize prevention strategies for this substantial health burden. Narrative data from Army safety, medical evacuation, and casualty reporting systems were reviewed to select incidents meeting inclusion criteria and assign established codes. Nondeployed (n=988) and deployed (n=254) injury rates were not statistically different (2.20 per 1,000 non-deployed person-years [p-yrs], 2.21 per 1,000 deployed p-yrs, respectively). More than 75% of injuries were temporarily disabling fractures, sprains, and strains, primarily to lower extremities. The most frequent activities associated with non-deployed fall injuries were sports (e.g., snowboarding and basketball; 22%), parachuting (20%), walking/marching (19%), and climbing (15%). Ice and snow were the leading hazard (43%). The most common associated activities among deployed soldiers were occupational tasks (53%), walking/patrolling (24%), climbing (23%), and sports (17%). Specific interventions that target the activities and hazards identified in this investigation are suggested as priorities to reduce Army fall-related injuries.

Physical Training, Fitness, and Injuries: Lessons Learned From Military Studies.

Injuries are the leading cause of medical encounters across the U.S. military services resulting in more than 2.0 million clinic visits per year. Almost 50% of military service members experience an injury each year and half of those injuries are caused by physical training (PT), exercise, or sports. To prevent a problem as large and complex as injuries in the military requires a systematic approach. Several key questions must be answered to effectively address a problem such as injuries: (1) how big is the problem? (2) what are the causes and risk factors for the problem? (3) do modifiable risk factors for the problem exist? and (4) what works to prevent the problem? The article discusses leading causes of injuries for U.S. Army populations. It then explores key risk factors for exercise and training-related injuries: (1) the amounts of training, (2) types of training activities, (3) participants level of fitness, and (4) personal health risk behaviors. The article concludes with a review of prevention strategies illustrating interventions that have been shown to be effective, and others that are not effective. The data presented suggest that PT and exercise cause injuries and that modifications of training are most likely to prevent the problem.

Exposure levels for chemical threat compounds: information to facilitate chemical incident response.

Although not widely known, a robust set of peer-reviewed public health and occupational exposure levels presently exist for key chemical warfare agents (CWAs) and certain acutely toxic industrial chemicals (TICs) identified as terrorist attack threats. Familiarity with these CWA and TIC exposure levels and their historic applications has facilitated emergency management decision-making by public and environmental health decision-makers. Specifically, multiple air, soil, and water exposure levels for CWAs and TICs summarized here have been extensively peer-reviewed and published; many have been recognized and are in use by federal and state health agencies as criteria for hazard zone prediction and assessment, occupational safety, and "how clean is clean enough" decisions. The key, however, is to know which criteria are most appropriate for specific decisions. While public safety is critical, high levels of concern often associated with perceived or actual proximity to extremely toxic chemical agents could result in overly cautious decisions that generate excessive delays, expenditure of scarce resources, and technological difficulties. Rapid selection of the most appropriate chemical exposure criteria is recommended to avoid such problems and expedite all phases of chemical incident response and recovery.

Decontamination and management of human remains following incidents of hazardous chemical release.

OBJECTIVE: To provide specific guidance and resources for systematic and orderly decontamination of human remains resulting from a chemical terrorist attack or accidental chemical release. DESIGN: A detailed review and health-based decision criteria protocol is summarized. Protocol basis and logic are derived from analyses of compound-specific toxicological data and chemical/physical characteristics. SETTING: Guidance is suitable for civilian or military settings where human remains potentially contaminated with hazardous chemicals may be present, such as sites of transportation accidents, terrorist operations, or medical examiner processing points. PATIENTS AND PARTICIPANTS: Guidance is developed from data-characterizing controlled experiments with laboratory animals, fabrics, and materiel. MAIN OUTCOME MEASURE(S): Logic and specific procedures for decontamination and management of remains, protection of mortuary affairs personnel, and decision criteria to determine when remains are sufficiently decontaminated are presented. RESULTS: Established procedures as well as existing materiel and available equipment for decontamination and verification provide reasonable means to mitigate chemical hazards from chemically exposed remains. Unique scenarios such as those involving supralethal concentrations of certain liquid chemical warfare agents may prove difficult to decontaminate but can be resolved in a timely manner by application of the characterized systematic approaches. Decision criteria and protocols to "clear" decontaminated remains for transport and processing are also provided. CONCLUSIONS: Once appropriate decontamination and verification have been accomplished, normal procedures for management of remains and release can be followed.

Respiratory health status of US Army personnel potentially exposed to smoke from 2003 Al-Mishraq Sulfur Plant fire.

OBJECTIVE: To assess the impact of exposure to a 2003 sulfur plant fire on the health of deployed US Army personnel. METHODS: The authors identified a small firefighter group known to be at the fire source and a larger, more dispersed population. Self-reported health status and respiratory health outcomes for these two groups were reviewed compared with two unexposed groups. RESULTS: Self-reported health concerns, difficulty breathing, and shortness of breath were common in the exposed. Rates for chronic respiratory conditions increased in all groups from before to after deployment. Postdeployment medical encounters for chronic respiratory conditions among the exposed did not differ significantly from the unexposed comparison groups. CONCLUSION: Potential exposure to the sulfur fire was positively associated with self-reported health concerns and symptoms but not with clinical encounters for chronic respiratory health conditions.

Developing Health-Based Pre-Planning Clearance Goals for Airport Remediation Following Chemical Terrorist Attack: Introduction and Key Assessment Considerations.

In the event of a chemical terrorist attack on a transportation hub, post-event remediation and restoration activities necessary to attain unrestricted facility reuse and re-entry could require hours to multiple days. While restoration timeframes are dependent on numerous variables, a primary controlling factor is the level of pre-planning and decision-making completed prior to chemical terrorist release. What follows is the first of a two-part analysis identifying key considerations, critical information, and decision criteria to facilitate post-attack and post-decontamination consequence management activities. A conceptual site model and human health-based exposure guidelines are developed and reported as an aid to site-specific pre-planning in the current absence of U.S. state or Federal values designated as compound-specific remediation or re-entry concentrations, and to safely expedite facility recovery to full operational status. Chemicals of concern include chemical warfare nerve and vesicant agents and the toxic industrial compounds phosgene, hydrogen cyanide, and cyanogen chloride. This work has been performed as a national case study conducted in partnership with the Los Angeles International Airport and The Bradley International Terminal. All recommended guidelines have been selected for consistency with airport scenario release parameters of a one-time, short-duration, finite airborne release from a single source followed by compound-specific decontamination.