Demographic, psychosocial, and physical fitness predictors of successful graduation from U.S. Army Ranger School.

U.S. Army Ranger School is an arduous 64-day leadership training course designed to simulate the stressors of combat. Although physical fitness has been shown to be an important predictor of successful graduation for Ranger School, psychosocial characteristics like self-efficacy and grit have not been examined. The purpose of this study is to identify personal, psychosocial, and fitness characteristics associated with successful completion of Ranger School. This study was a prospective cohort examining the association of baseline characteristics of Ranger School candidates with a primary outcome of graduation success. Multiple logistic regression was performed to determine the contribution of demographics, psychosocial, fitness and training characteristics to graduation success. Out of 958 eligible Ranger Candidates, this study obtained graduation status for 670 students, 270 (40%) of which graduated. Soldiers who graduated were younger, more likely to come from units with a higher proportion of previous Ranger School graduates, had higher self-efficacy and faster 2-mile run times. The results from this study suggest that Ranger students should arrive in optimal physical conditioning. Furthermore, training programs that optimize student self-efficacy and units with a high proportion of successful Ranger graduates may confer advantage for this challenging leadership course.

Injuries and Factors Associated with Injuries Among U.S. Army Band Musicians.

The Department of Defense is the largest employer of full-time musicians. In the U.S. military, many musicians experience unique occupational exposures such as extended periods of standing, sitting, and marching for rehearsals and performances, static and non-neutral postures, and a variety of repetitive motions while playing instruments. These exposures are in addition to physical training and fitness standards required of U.S. Army soldiers. METHODS: An electronic survey was administered to active-duty U.S. Army Band musicians. The survey collected demographics, personal characteristics, Army Physical Fitness Test performance, occupational demands, health behaviors, and injuries from October 2017 to December 2018. Survey responses were combined with medical and physical fitness performance records. Descriptive statistics were reported and factors associated with injuries were investigated. RESULTS: There were 465 Army Band members in this population, with approximately half (49%) completing the survey. Most survey respondents (81%) reported an injury in the past year, which they predominantly attributed to overuse (54%). Leading reported activities resulting in injury included running for physical training (21%), repetitive movements while playing an instrument (11%), and standing while playing (11%). A majority of survey respondents (60%) also had a medical encounter for an injury. Factors significantly associated with injury among men were lower aerobic fitness and higher body fat percentage; additional unadjusted factors associated with injury among all Army Band soldiers included female sex, older age, and longer periods of marching and standing while playing. CONCLUSIONS: Injury prevention initiatives for Army Band musicians should focus on the reduction of overuse and repetitive motion injuries. Suggested prevention strategies include balanced physical training, ergonomic adjustments, rehearsal breaks, and leadership support for injury prevention efforts.

Injury Risk Factors Associated With Weight Training.

ABSTRACT: Grier, T, Brooks, RD, Solomon, Z, and Jones, BH. Injury risk factors associated with weight training. J Strength Cond Res 36(2): e24-e30, 2022-The purpose of this evaluation was to identify injury risk factors associated with weight training (WT). Subjects were 4,785 men and 542 women in a U.S. Army Division. Personal characteristics, unit training, personal training, fitness, and 12-month injury history were obtained by an electronic survey. Risk factors for WT injuries were explored using backward stepping multivariable logistic regression. Risk ratios, odds ratios (ORs), and 95% confidence intervals (95% CIs) were calculated for each risk factor. Over a one-year period, 4.5% of men and 0.6% of women experienced a WT injury. Weight-training injury incidence was 0.31 and 0.05 per 1,000 hours of WT for men and women, respectively. Overall, men were 7.4 times more likely to experience a WT injury compared with women. For men who participated in WT, independent risk factors for a WT injury included older age (OR [23-27/≤ 22 years] = 1.99, 95% CI 1.22-3.27; OR [>28/≤ 22 years] = 2.48, 95% CI 1.52-4.03) and higher amounts of personal WT per week (OR [60-165/≥ 166 minutes] = 0.58, 95% CI 0.39-0.88; and OR [15-59/≥ 166 minutes] = 0.40, 95% CI 0.24-0.66). A linear trend was revealed indicating an increasing risk of a WT injury with greater amounts of time spent WT per week (p < 0.01). Performing moderate amounts of WT may reduce the risk of experiencing a WT injury. However, because muscle strength is an important component of fitness for Soldiers, specialized WT programs that improve strength while minimizing injury risks are needed.

Comprehensive Physical Activity Assessment During U.S. Army Basic Combat Training.

ABSTRACT: Alemany, JA, Pierce, JR, Bornstein, DB, Grier, TL, Jones, BH, and Glover, SH. Comprehensive physical activity assessment during U.S. Army Basic Combat Training. J Strength Cond Res 36(12): 3505-3512, 2022-Physical activity (PA) volume, intensity, and qualitative contextual information regarding activity type and loads carried are limited during U.S. Army Basic Combat Training (BCT). The purpose of this study was to characterize daily (05:00-20:00 hours) PA during BCT using a comprehensive approach. During 2 10-week BCT cycles ( n = 40 trainees per cycle), pedometers, accelerometers, and direct observation were used to estimate daily step count, PA volume, and intensity. Physical activity intensity was categorized by metabolic equivalents (METs) such as "sedentary" (1-2 METs), "light" (2-3 METs), "moderate" (3-6 METs), or "vigorous" (≥6 METs). Daily PA data were analyzed longitudinally using linear mixed models, with significance set at p ≤ 0.05. The mean daily step count was 13,459 ± 4,376 steps, and the mean daily accelerometer-assessed PA volume and intensity were as follows: sedentary: 505 ± 98 minutes, light: 190 ± 78 minutes, moderate: 168 ± 51 minutes, and vigorous: 14 ± 14 minutes, with no differences between cycles for all measures ( p > 0.50). Cumulative time on feet (∼50%) and sitting (20-25%) accounted for most daily activity types during both cycles. Trainees, on average, carried between 3 and 9 kg, and ≥9 kg, for 60% and 10% of the monitored day, respectively. Basic Combat Training's physical demands are high, where trainees achieved 1.7 to 2.7 times greater daily ambulation and 6 times the recommended weekly moderate-to-vigorous PA compared with civilian counterparts and performed weight-bearing load carriage for nearly half of the day. Basic Combat Training-associated PA may increase injury risk among trainees unaccustomed to arduous PA and exercise. Implementing national PA policies to improve physical fitness and facilitate acclimatization to BCT's high physical demands could reduce public health burdens and military nonreadiness.

The Combined Effect of Cigarette Smoking and Fitness on Injury Risk in Men and Women.

BACKGROUND: Prior studies have identified cigarette smoking and low fitness as independent risk factors for injury; however, no studies have evaluated the combined effect of cigarette smoking and fitness on injury risk. OBJECTIVE: To evaluate the combined effect of cigarette smoking and fitness on injury risk in men and women. DESIGN: This is a secondary analysis of data collected from US Army recruits (n = 2000) during basic combat training within the United States in 2007. Physical training and fitness, cigarette smoking, and prior injury data were obtained from questionnaires, whereas demographic and injury data were obtained from medical and basic combat training unit records. Chi-squared tests were used to assess differences in injury risk by fitness level and cigarette smoking. Relative risk values were calculated with 95% confidence intervals. RESULTS: The primary findings showed that smokers experienced 20%-30% higher risk of injury than nonsmokers. In addition, higher aerobic and muscular fitness was generally not protective against injury between least fit and more fit smokers. However, higher fitness was protective against injury between least and more fit nonsmokers, with least fit nonsmokers being 30%-50% more likely to experience an injury than fit nonsmokers. CONCLUSION: This study revealed that higher aerobic and muscular fitness was not protective against injury among smokers; however, it was protective against injury among nonsmokers. Further implementation of smoking cessation programs may be beneficial for military and civilian personnel who are required to be physically fit in order to carry out their job responsibilities. IMPLICATIONS: Male and female smokers experienced significantly higher risk of injury than nonsmokers. Although higher fitness is protective against injury in nonsmokers, the protective effect of fitness is lost among smokers. In an attempt to reduce injury risk among military and emergency personnel, smoking cessation programs should be further implemented among both more fit and less fit smokers.

A prospective field study of U.S. Army trainees to identify the physiological bases and key factors influencing musculoskeletal injuries: a study protocol.

BACKGROUND: Musculoskeletal injuries (MSKIs) are common in military trainees and present a considerable threat to occupational fitness, deployability, and overall military readiness. Despite the negative effects of MSKIs on military readiness, comprehensive evaluations of the key known and possible risk factors for MSKIs are lacking. The U.S. Army Research Institute of Environmental Medicine (ARIEM) is initiating a large-scale research effort, the ARIEM Reduction in Musculoskeletal Injury (ARMI) Study, to better understand the interrelationships among a wide range of potential MSKI risk factors in U.S. Army trainees in order to identify those risk factors that most contribute to MSKI and may be best targeted for effective mitigation strategies. METHODS: This prospective study aims to enroll approximately 4000 (2000 male and 2000 female) U.S. Army trainees undergoing Basic Combat Training (BCT). Comprehensive in-person assessments will be completed at both the beginning and end of BCT. Participants will be asked to complete surveys of personal background information, medical history, physical activity, sleep behaviors, and personality traits. Physical measurements will be performed to assess anthropometrics, tibial microarchitecture and whole body bone mineral density, muscle cross-sectional area, body composition, and muscle function. Blood sampling will be also be conducted to assess musculoskeletal, genetic, and nutritional biomarkers of risk. In addition, participants will complete weekly surveys during BCT that examine MSKI events, lost training time, and discrete risk factors for injury. Participants' medical records will be tracked for the 2 years following graduation from training to identify MSKI events and related information. Research hypotheses focus on the development of a multivariate prediction model for MSKI. DISCUSSION: Results from this study are expected to inform current understanding of known and potential risk factors for MSKIs that can be incorporated into solutions that optimize Soldier health and enhance military readiness.

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.

Effects of Physical Training and Fitness on Running Injuries in Physically Active Young Men.

Grier, TL, Canham-Chervak, M, Anderson, MK, Bushman, TT, and Jones, BH. Effects of physical training and fitness on running injuries in physically active young men. J Strength Cond Res 31(1): 207-216, 2017-The purpose of this investigation was to determine the effects of physical training (PT) and fitness on risks for running-related injuries (RRIs) in physically active young men. Personal characteristics, PT, Army Physical Fitness Test scores, and injury data were obtained by survey. Army Physical Fitness Test variables (push-ups, sit-ups, and 2-mile run) were converted into quartiles (Q), where Q1 = lowest performance and Q4 = highest performance. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using multivariate logistic regression. Over 4,000 (n = 4,236) soldiers were surveyed. Running injury incidence was 14%. A greater risk of an RRI was associated with older age (OR31+/<22 years = 1.62, 95% CI, 1.21-2.18), higher BMI ((Equation is included in full-text article.)), and total distance ran per week during unit PT (OR16.1+/1-5 miles = 1.66, 95% CI, 1.15-2.41). A lower risk of an RRI was associated with total distance run per week during personal PT (OR5.1-10/1-5 miles = 0.70, 95% CI, 0.53-0.91, OR10.1-16 +/1-5 miles = 0.58, 95% CI, 0.35-0.97, OR16.1+/1-5 miles = 0.54, 95% CI, 0.30-0.98), higher aerobic endurance as measured by 2-mile run performance (ORQ4/Q1 = 0.50, 95% CI, 0.35-0.72), and unit resistance training ≥3 times a week (OR≥3 times per week/none = 0.46, 95% CI, 0.29-0.73). Greater personal PT running mileage decreased injuries in this population suggesting that the increased protective effect of higher aerobic fitness outweighed the injurious effect of running more miles during personal PT. Countermeasures to prevent RRIs could entail enhancing aerobic endurance, providing opportunities for personal aerobic training, monitoring for excessive unit PT running mileage and encouraging unit resistance training ≥3 times per week.

Evaluating Injury Risk and Gender Performance on Health- and Skill-Related Fitness Assessments.

Grier, TL, Canham-Chervak, M, Bushman, TT, Anderson, MK, North, WJ, and Jones, BH. Evaluating injury risk and gender performance on health- and skill-related fitness assessments. J Strength Cond Res 31(4): 971-980, 2017-The purpose of this analysis was to investigate the association of injury risk and gender performance on health- and skill-related fitness assessments. A survey was used to collect personal characteristics and Army Physical Fitness Test scores (2-mile run, push-ups, and sit-ups). Within the same day, 9 physical fitness assessments were performed. Percent body fat was estimated using height, weight, age, and sex. All fitness assessment data were categorized into tertiles of high, moderate and low performance. To investigate potential injury risk predicted by fitness assessment performance, injury risk ratios, odds ratios (ORs), and 95% confidence intervals (CIs) were calculated using medical record data. A total of 3,264 soldiers completed surveys and physical fitness assessments. Tertiles of fitness performance with men and women combined showed that on an average, 14% of women and 70% of men were in the moderate- and high-performance groups. Among men, higher injury risk was independently associated with low performance on a 2-mile run (ORslow/fast = 1.51, 95% CI 1.18-1.94) and low performance on a weighted 300-yard shuttle run (ORslow/fast = 1.36, 95% CI 1.06-1.74). For women, a higher risk of injury was associated with low performance on the 2-mile run (ORslow/fast = 2.38, 95% CI 1.04-5.74). Therefore, out of the 13 fitness assessments, the 2-mile run and weighted 300-yard shuttle run can also (in addition to measuring performance) be utilized to identify soldiers or athletes who are at a higher risk of experiencing an injury.

Validity of Self-Reported Physical Fitness and Body Mass Index in a Military Population.

Many epidemiological studies rely on valid physical fitness data. The purpose of this investigation was to assess the validity of self-reported Army Physical Fitness Test (APFT) data and determine whether men and women recall APFT performance differently. U.S. Army soldiers (N = 1,047) completed a survey, including questions on height, weight, and most recent APFT performance. Height, weight, and APFT performance were also obtained from unit records. The mean ± SDs for unit and self-reported push-up repetitions were 63.5 ± 13.1 and 66.3 ± 14.0 for men and 37.7 ± 12.8 and 40.2 ± 12.8 for women, respectively. The mean ± SD for unit- and self-reported sit-up repetitions were 66.3 ± 11.4 and 68.1 ± 12.1 for men and 64.2 ± 13.6 and 66.5 ± 12.9 for women, respectively. The mean ± SD unit- and self-reported 2-mile run times were 15.2 ± 1.8 and 14.9 ± 1.6 minutes for men, and 18.0 ± 2.9 and 17.4 ± 1.9 minutes for women, respectively. Unit- and self-reported body mass indices (BMIs) (calculated by height and weight) were 26.4 ± 3.4 and 26.3 ± 3.6 for men and 24.6 ± 2.8 and 24.2 ± 3.3 for women. Correlations between unit- and self-reported scores for push-ups, sit-ups, 2-mile run, height, weight, and BMI were 0.82, 0.78, 0.85, 0.87, 0.97, and 0.88 for men and 0.86, 0.84, 0.87, 0.78, 0.98, and 0.78 for women, respectively. On average, men and women slightly overreported performance on the APFT and overestimated height, resulting in underestimated BMI. There was no difference in recall ability between men and women (p > 0.05). The very good to excellent correlations (r = 0.78-0.98) between unit- and self-reported scores indicate that self-reported data are valid for capturing physical fitness performance in this population.

Pain on Functional Movement Screen Tests and Injury Risk.

The Functional Movement Screen (FMS) is a tool intended to evaluate limitations or asymmetries of movement to detect individuals at risk for exercise- and sports-related injury. The purpose was to determine the association and predictive value of specific FMS tests with injury risk in physically active men. Soldiers aged 18-57 years completed the FMS (n = 2,476). Demographic and fitness data were collected by survey. Medical record data for any, overuse, and traumatic injury 6 months after the assessment were obtained. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value were calculated along with receiver operator characteristics to determine area under the curve (AUC). Risks, risk ratios, odds ratios (ORs), and 95% confidence intervals were calculated to assess injury risks. Multivariate logistic regression identified that pain on 5 of the 7 tests was associated with greater risk for any injury (OR = 1.50-3.51): deep squat, hurdle step, in-line lunge, trunk stability push-up, and rotary stability. However, FMS registered low sensitivity, PPV, and AUC for all 7 tests for the 3 injury types (2-24% sensitivity, 16-74% PPV, and 50-58% AUC). Although the presence of pain was associated with a higher risk of injury on 5 tests, a low sensitivity, PPV, and AUC were displayed. Therefore, caution is advised when implementing the FMS as a screening tool in an Army or similarly active population as it could lead to prevention and treatment resources being directed toward individuals who are not at greater risk for injury.

A retrospective cohort study on the influence of UV index and race/ethnicity on risk of stress and lower limb fractures.

BACKGROUND: Low vitamin D status increases the risk of stress fractures. As ultraviolet (UV) light is required for vitamin D synthesis, low UV light availability is thought to increase the risk of vitamin D insufficiency and poor bone health. The purpose of this investigation was to determine if individuals with low UV intensity at their home of record (HOR) or those with darker complexions are at increased risk of developing stress fractures and lower limb fractures during U.S. Army Basic Combat Training (BCT). METHODS: This was a retrospective cohort study using the Armed Forces Health Surveillance Center data repository. All Basic trainees were identified from January 1997 to January 2007. Cases were recruits diagnosed with stress fractures and lower limb fractures during BCT. The recruit's home of record (HOR) was identified from the Defense Manpower Data Center database. The average annual UV intensity at the recruits' HOR was determined using a U.S National Weather Service database and recruits were stratified into low (≤3.9); moderate (4.0-5.4), and high (≥5.5) UV index regions. Race was determined from self-reports. RESULTS: The dataset had 421,461 men and 90,141 women. Compared to men, women had greater risk of developing stress fractures (odds ratio (OR) = 4.5, 95% confidence interval (95%CI) = 4.4-4.7, p < 0.01). Contrary to the hypothesized effect, male and female recruits from low UV index areas had a slightly lower risk of stress fractures (male OR (low UV/high UV) = 0.92, 95%CI = 0.87-0.97; females OR = 0.89, 95%CI = 0.84-0.95, p < 0.01) and were at similar risk for lower limb fractures (male OR = 0.98, 95%CI = 0.89-1.07; female OR = 0.93, 95%CI = 0.80-1.09) than recruits from high UV index areas. Blacks had lower risk of stress and lower limb fractures than non-blacks, and there was no indication that Blacks from low UV areas were at increased risk for bone injuries. CONCLUSIONS: The UV index at home of record is not associated with stress or lower limb fractures in BCT. These data suggest that UV intensity is not a risk factor for poor bone health in younger American adults.

Physical and behavioral characteristics of soldiers acquiring recommended amounts of sleep per night.

OBJECTIVES: Only one-third of U.S. Army Soldiers meet the recommended sleep guideline of 7 or more hours per night. Soldiers meeting the recommended sleep guideline are more likely to perform better on cognitive and physical tasks. The purpose of this analysis was to compare the physical and behavioral characteristics of Soldiers who met and did not meet the sleep recommendation guideline and determine associations between physical and behavioral characteristics and the acquisition of recommended amounts of sleep per night. METHODS: A survey was administered to U.S. Army Soldiers. Adjusted odds ratios and corresponding 95% confidence intervals were calculated to determine associations between achieving the recommended number of hours of sleep per night and age, physical characteristics, health behaviors, physical training, and physical performance. RESULTS: A survey was completed by 4229 men and 969 women. Male Soldiers who met the recommended sleep requirement had lower estimated body fat [20.3 ± 4.2% vs. 21.1 ± 4.4%], were less likely to use tobacco [11.5% vs. 16.2%] and exercised more [259 ± 226 vs. 244 ± 224 min/wk] compared with those who did not obtain 7 hours of sleep per night. Female Soldiers who met the recommended sleep requirement had lower estimated body fat [31.4 ± 4% vs. 32.1 ± 4.6%] and exercised more [258 ± 206 vs. 241 ± 216 min/wk] compared with those who did not obtain 7 hours of sleep per night. CONCLUSION: Soldiers who choose to adopt healthy lifestyle characteristics may be more likely to meet the recommended sleep duration guideline.

Injury rates and injury risk factors among Federal Bureau of Investigation new agent trainees.

BACKGROUND: A one-year prospective examination of injury rates and injury risk factors was conducted in Federal Bureau of Investigation (FBI) new agent training. METHODS: Injury incidents were obtained from medical records and injury compensation forms. Potential injury risk factors were acquired from a lifestyle questionnaire and existing data at the FBI Academy. RESULTS: A total of 426 men and 105 women participated in the project. Thirty-five percent of men and 42% of women experienced one or more injuries during training. The injury incidence rate was 2.5 and 3.2 injuries/1,000 person-days for men and women, respectively (risk ratio (women/men) = 1.3, 95% confidence interval = 0.9-1.7). The activities most commonly associated with injuries (% of total) were defensive tactics training (58%), physical fitness training (20%), physical fitness testing (5%), and firearms training (3%). Among the men, higher injury risk was associated with older age, slower 300-meter sprint time, slower 1.5-mile run time, lower total points on the physical fitness test (PFT), lower self-rated physical activity, lower frequency of aerobic exercise, a prior upper or lower limb injury, and prior foot or knee pain that limited activity. Among the women higher injury risk was associated with slower 300-meter sprint time, slower 1.5-mile run time, lower total points on the PFT, and prior back pain that limited activity. CONCLUSION: The results of this investigation supported those of a previous retrospective investigation emphasizing that lower fitness and self-reported pain limiting activity were associated with higher injury risk among FBI new agents.

Military parachuting injuries, associated events, and injury risk factors.

INTRODUCTION: The purpose of this investigation was to examine injury incidence, events associated with injury, and injury risk factors during parachuting in an Army airborne infantry unit. METHODS: Injury data were obtained by the investigators on the drop zone and confirmed by a physician. Operational data (potential injury risk factors) were obtained from routine reports published by the infantry unit. Weather data were obtained using a Kestrel Model 4500 pocket weather tracker. RESULTS: There were a total of 23,031 jumps resulting in 242 injured soldiers for a crude injury incidence of 10.5 per 1000 jumps. Parachute entanglement incidence was 0.5 per 1000 jumps. Where an event associated with the injury could be determined (67% of cases), these included ground impact (75%), static line problems (11%), tree landings (4%), entanglements (4%), and aircraft exits (3%). Univariate analysis showed that higher injury risk was associated with night jumps (versus day jumps), combat loads (versus unloaded jumps), higher wind speeds, higher dry bulb temperatures, higher humidity, C17 Globemaster or C130 Hercules aircrafts (compared to the other aircraft), exits through aircraft side doors (versus tailgates), and entanglements. Multivariate analysis indicated that independent risk factors for injuries included night jumps, combat loads, higher wind speeds, higher dry bulb temperatures, and entanglements. DISCUSSION: This investigation provided injury incidence, events associated with injury, and quantitative assessments of injury risk factors and their interactions during military parachuting. An appreciation of these subjects can assist medical and operational planners in further reducing the incidence of injury during airborne operations.

Risk factors for medical discharge from United States Army Basic Combat Training.

Past studies indicated that overall Basic Combat Training (BCT) attrition (discharge) was associated with various risk factors. BCT has changed considerably since many of these studies were conducted. This study examined Soldiers medically attrited from BCT. Potential attrition risk factor data on recruits (n = 4,005) were collected from medical records, BCT unit records, and questionnaires. Attrition data from Fort Jackson, South Carolina, showed 203 medical discharges. Cox regression (univariate and multivariate) obtained hazard ratios and 95% confidence intervals for attrition risk factors. Higher attrition risk was associated with female gender. Higher attrition risk for men was associated with cigarette smoking, injury during BCT, and less exercise before BCT. Higher attrition risk for both genders was associated with failure on the initial 2-mile run test and separated or divorced marital status. Attrition risk factors found in this study were similar to those previously identified despite changes in BCT.

Risk factors for injuries in the U.S. Army Ordnance School.

OBJECTIVE: To investigate risk factors for time-loss injuries among soldiers attending U.S. Army Ordnance School Advanced Individual Training. METHODS: Injuries were obtained from an injury surveillance system. A health questionnaire provided data on age, race, rank, current self-reported injury and illness, and tobacco use. Fitness data was obtained from operations office. RESULTS: Cumulative time-loss injury incidence was 31% for men and 54% for women. For men, higher risk of injury was associated with race, a current self-reported injury, smoking before entering the Army, lower sit-up performance, and slower 2-mile run times. For women, higher risk of injury was associated with race, a current self-reported injury, and slower 2-mile run times. CONCLUSION: Smoking cessation and fitness training before entry are potential strategies to reduce injuries among soldiers in the Ordnance School.

Factors associated with medical problems among young non-deployed U.S. military working dogs.

The goals of this project were to quantify medical problems among a population of Military Working Dogs (MWDs) and analyze factors associated with common medical conditions. Medical conditions recorded in veterinary Master Problem List (MPL) entries for 774 young, non-deployed, active MWDs were categorized and combined with demographic information to analyze risk factors. Most dogs were male (74%), German Shepherd (39%) or Belgian Malinois (31%) breeds, certified in Explosive Detection (60%), and had a dark coat color (83%). Ages ranged from one to six years, with an average of 2.6 years (± 0.5 years). Eighty-three percent of dogs had a non-surgical medical problem in their record. The most common non-surgical medical problems were dermatologic (25% of MPL entries), alimentary (21%), dental (15%), soft-tissue injury (10%), and musculoskeletal conditions (4%). Factors associated with each medical condition were breed (Odds Ratios 1.96-8.24), sex and spay/neuter status (ORs 1.78-5.77), occupational duty certification (ORs 2.65-3.62), military command location (ORs 2.32-7.44), and military branch (OR 5.16). As MWDs are a valuable asset for the Department of Defense, training and work conditions for the identified at-risk groups of MWDs should be further assessed to maximize their operational capabilities and assess the potential to serve as sentinel indicators for human diseases. Improved understanding of the most common medical problems affecting MWDs, and the identification of factors associated with these conditions, can help drive changes in their preventive care.

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.

Sleep duration and musculoskeletal injury incidence in physically active men and women: A study of U.S. Army Special Operation Forces soldiers.

PURPOSE: In physically demanding occupations or athletic populations, sleep has been shown to be an important factor for both performance and recovery. However, evidence is limited on sleep duration and its association with musculoskeletal injury risk in physically active populations. Therefore, the purpose of this analysis was to evaluate the relationship between sleep duration and musculoskeletal injury incidence in a population of physically active men and women. METHODS: Data were collected via electronic survey and analyzed for 7,576 soldiers from the United States Army Special Operations Command. RESULTS: This population was mostly men (95%) ≤ 35 years old (70%). The incidence of musculoskeletal injury was 53% over the twelve months before survey administration. After adjusting for other covariates, soldiers who slept ≤ 4 hours were 2.35 (95% CI: 1.89-2.93, p <0.01) times more likely to experience a musculoskeletal injury compared with those who slept eight ≥ 8 hours. When stratified by age (≤ 35 years, > 35 years), older men were found to have significantly higher risk of a musculoskeletal injury than their younger counterparts across all sleep duration groups. CONCLUSIONS: These findings suggest that sleep duration may be inversely related to risk of musculoskeletal injury. It is possible that interventions targeted at sleep may have a positive impact on prevention of musculoskeletal injuries within physically active populations.