Gender differences in the associations of body mass index, physical fitness and tobacco use with lower extremity musculoskeletal injuries among new US Army soldiers

Ankle sprains in male Israeli infantry soldiers during training: prevalence and risk factors

BACKGROUND

Given the high incidence and heavy burden of ankle sprains in recruits, large-scale, multifactorial investigations into potential risk factors are warranted. This study aimed to identify the incidence of ankle sprains and associated risk factors among new military recruits during their infantry training.

METHODS

The study included 365 infantry recruits (aged 18-21 years), who were inducted into service in March 2022. These recruits were monitored for ankle sprains throughout their basicy and advanced infantry training by a physiotherapist. Preinduction smoking habits, physical fitness preparation and recurrent ankle sprains were recorded. Anthropometric measures, lower-extremity functional movement, Achilles tendon structure, perceived ankle instability, and mechanical ankle instability were assessed at the onset of both training periods.

RESULTS

Ankle sprains were diagnosed in 109 trainees (29.9%) during both the basic and the advanced training periods. Preinduction recurrent ankle sprains were reported by 28.2% of the participants. The relative risk of a recruit with preinduction ankle sprains suffering a subsequent sprain during training was 1.66 (p=0.001). Logistic regression analysis indicated that reduced proprioception ability (OR=0.002), higher body mass index (OR=1.08), preinduction recurrent sprains (OR=1.95) and lack of physical fitness preparation (OR=3.12) were related to ankle sprains throughout the complete basic-and-advanced training period. Preinduction recurrent ankle sprains (OR=3.37) and reduced Achilles tendon quality (OR=1.30) were associated with ankle sprains during the advanced training period.

CONCLUSIONS

Lower-extremity functional movement, body mass index, preinduction recurrent sprains, physical preparation and reduced Achilles tendon quality were associated with the risk of ankle sprains during training. These findings could contribute to developing prevention and intervention programmes for reducing ankle sprains in military trainees.

Fasciotomy and Occupational Separation among US Service Members with Lower Extremity Chronic Exertional Compartment Syndrome

PURPOSE

Lower extremity chronic exertional compartment syndrome (LE-CECS) can limit rigorous physical activity, particularly in the US military, and fasciotomy is a potential treatment. Associations between LE-CECS, fasciotomy, and occupational outcomes appear understudied. We studied active-duty US service members to identify whether LE-CECS diagnoses and fasciotomy for LE-CECS predict military service separation.

METHODS

We conducted a retrospective cohort study of 1,103,417 individuals who entered service during 2011 to 2017. Distributions of separation statuses and independent variables were tabulated, and sex-specific multivariable regression models were computed for separation outcomes.

RESULTS

LE-CECS was associated with a 474% medical service separation risk in men (95% confidence interval (CI) for adjusted risk ratio: 5.21 to 6.33) and a 282% increase in women (CI: 2.99 to 4.88). Among 1947 patients with LE-CECS, men saw a 57% nonmedical separation risk increase (CI: 1.27 to 1.93) and women had a 119% increase (CI: 1.10 to 4.35) when anterior and/or lateral compartment procedures occurred. Men with LE-CECS and any posterior procedures saw a 47% nonmedical separation risk increase (CI: 1.17 to 1.86). Men with anterior and/or lateral procedures and any posterior procedures experienced 36% (CI: 1.09 to 1.71) and 78% (CI: 1.40 to 2.26) medical separation risk increases, respectively. No statistically significant risk increases for the outcomes were otherwise seen for women.

CONCLUSIONS

LE-CECS was associated with increased military service discharge risks. Among the affected patients, positive effects on career longevity were not seen in association with fasciotomy. However, fasciotomy could simply serve as a marker of the most refractory cases that are least likely to continue service. More study is needed to clarify causal pathways and identify patients who may derive career benefits from surgical treatment.

High Physical Exposure During Female Recruits' Basic Military Training in Sweden-A Descriptive Study

INTRODUCTION

There is a knowledge gap concerning the occurrence of physical complaints/injuries, i.e., musculoskeletal disorders (MSD), among Swedish women who undergo basic military training (BMT). The aims were to describe prevalence and factors related to MSD and explore physical exposure and performance in Swedish female recruits during BMT.

MATERIALS AND METHODS

A total of 144 females (mean age 22 years) who underwent BMT in 2016 participated in this cross-sectional study. Data regarding self-reported MSD, physical performance, physical activity and exercise, motivation and mental and physical preparation, and physical exposure during BMT and perceived health were collected at the end of BMT through the Musculoskeletal Screening Protocol questionnaire. Additional data on muscle strength were retrieved from IsoKai isokinetic lift tests. Descriptive and analytic (paired samples t-test and logistic binary regression) statistics were used.

RESULTS

The prevalence of MSD was high, with 33% (n = 48) reporting MSD before BMT, 78% (n = 113) during, and 50% (n = 72) at the end of BMT. Knee and upper back were the most frequently reported MSD locations. Forty-four (30%) participants felt insufficiently physically prepared for BMT. The physical exposure was high with loaded marches/runs and carrying heavy loads as the most demanding tasks. The longest walking distance was reportedly 55 km, and the reported maximum load was 50 kg. Forty-five participants (31%) had carried a load representing over 50% of their body weight. Most participants reported good to excellent health at the end of BMT. There was a small (8 N) but significant (P = 0.045) increase in mean force over time. Two variables, MSD before BMT (odds ratio 2.24, P = 0.03) and being physically unprepared (odds ratio 3.03, P < 0.01), were associated with MSD at the end of BMT.

CONCLUSION

This study showed that the prevalence of MSD in Swedish female recruits was high before, during, and at the end of BMT, with knee and upper back as the most frequent locations. Although the physical exposure during BMT was occasionally high, self-rated health was mainly perceived as good to excellent at the end of BMT. Previous MSD and being physically unprepared were related to MSD at the end of BMT. These important and relevant findings indicate the necessity for implementing interventions to increase physical fitness and treat MSD at the beginning of BMT.

Risk factors for musculoskeletal-related occupational disability among US Army soldiers

INTRODUCTION

Minimising temporary and permanent disability associated with musculoskeletal conditions (MSK-D) is critical to the mission of the US Army. Prior research has identified potentially actionable risk factors for overall military disability and its MSK-D subset, including elevated body mass index, tobacco use and physical fitness. However, prior work does not appear to have addressed the impact of these factors on MSK-D when controlling for a full range of factors that may affect health behaviours, including aptitude scores that may serve as a proxy for health literacy. Identifying risk factors for MSK-D when providing control for all such factors may inform efforts to improve military readiness.

METHODS

We studied 494 757 enlisted Army soldiers from 2014 to 2017 using a combined medical and administrative database. Leveraging data from the Army's digital 'eProfile' system of duty restriction records, we defined MSK-D as the first restriction associated with musculoskeletal conditions and resulting in the inability to deploy or train. We used multivariable Cox proportional hazards regression to assess the associations between incident MSK-D and selected risk factors including aptitude scores, physical fitness test scores, body mass index and tobacco use.

RESULTS

Among the subjects, 281 278 (45.14%) experienced MSK-D. In the MSK-D hazards model, the highest effect size was for failing the physical fitness test (adjusted HR=1.63, 95% CI 1.58 to 1.67, p<0.001) compared with scoring ≥290 points.

CONCLUSIONS

The analysis revealed the strongest associations between physical fitness and MSK-D. Additional efforts are warranted to determine potential mechanisms for the observed associations between selected factors and MSK-D.

Financial Impact of Embedded Injury-Prevention Experts in US Army Initial Entry Training

CONTEXT

The US Army embedded injury-prevention experts (IPEs), specifically athletic trainers and strength and conditioning coaches, into initial entry training (IET) to limit musculoskeletal (MSK) conditions and their negative consequences. However, little is known about the financial impact of IPEs.

OBJECTIVE

To assess whether IPEs were associated with fewer sunk training costs due to MSK-related early discharges from service.

DESIGN

Retrospective cohort study.

SETTING

Database of US Army soldiers' administrative, medical, and readiness records.

PATIENTS OR OTHER PARTICIPANTS

A total of 198 166 soldiers (age = 20.7 ± 3.2 years, body mass index = 24.4 ± 3.5 kg/m2) who began IET during 2014 to 2017.

MAIN OUTCOME MEASURE(S)

Early discharge from service was defined as occurring within 6 months of beginning IET. All IET sites employed IPEs from 2011 to 2017, except for 2 sites during April to November 2015. Soldiers who began IET at these 2 sites during these times were categorized as not having IPE exposure. All others were categorized as having IPE exposure. The unadjusted association between IPE access and MSK-related early discharge from service was assessed using logistic regression. Financial impact was assessed by quantifying differences in yearly sunk costs between groups with and those without IPE exposure and subtracting IPE hiring costs.

RESULTS

Among 14 094 soldiers without IPE exposure, 2.77% were discharged early for MSK-related reasons. Among 184 072 soldiers with IPE exposure, 1.01% were discharged. Exposure to IPEs was associated with reduced odds of MSK-related early discharge (odds ratio = 0.36, 95% CI = 0.32, 0.40, P < .001) and a decrease in yearly sunk training costs of $11.19 to $20.00 million.

CONCLUSIONS

Employing IPEs was associated with reduced sunk costs because of fewer soldiers being discharged from service early for MSK-related reasons. Evidence-based recommendations should be developed for guiding policy on the roles and responsibilities of IPEs in the military to reduce negative outcomes from MSK conditions and generate a positive return on investment.

Evaluation of the Success of Weight Loss Programs Using the Fit for Performance Curriculum

INTRODUCTION

Overweight and obesity rates continue to rise among U.S. Army soldiers, which impacts their overall readiness status and puts them at greater risk for musculoskeletal injury and development of chronic disease. To address the concern with obesity and ensure that Soldiers are meeting body composition standards, the Army offers Fit for Performance-Weight Loss Strategies curriculum, a program of standardized material on nutrition and physical activity presented over six 1-hour sessions. This study aimed to evaluate the success and attrition of weight loss programs using the Fit for Performance curriculum in an Army setting among TRICARE regions.

MATERIALS AND METHODS

This retrospective cohort study consolidated data on participants in weight loss programs using the Fit for Performance curriculum. It examines attrition rates, weight loss, change in body mass index (BMI), factors influencing weight loss, and attrition based on geographical location. Statistical analysis was completed using R Core Team software, version 3.6.1, for t-tests, linear regression, and analysis of variance. Significance was set at P ≤ .05. This study was determined to be exempt by the Walter Reed National Military Hospital Institutional Review Board.

RESULTS

In total, 8,336 U.S. Army soldiers (80% male, mean age = 26.2 ± 6.9 years) participated in the program. Attrition rates were high (96.4%). Those who attended 4-6 sessions lost significantly more weight than those who attended 1-3 sessions (0.72 kg [1.60 lbs], P < .001); however, weight lost was not clinically significant. Sex, age, and number of sessions attended influenced to the amount of weight lost, but only accounted for 4% of the variation. Among TRICARE regions there was a significant difference in attrition rates, with those in the Western (1.2 sessions, P < .001) and Overseas (1.6 sessions, P < .001) regions attending statistically fewer sessions than those in the Eastern region.

CONCLUSIONS

Consistent attendance in a weight loss program promotes changes in BMI, which may improve the health of the force. However, the factors influencing these changes are unclear. The results indicate opportunities to re-examine current processes and the program elements to encourage increased or complete participation and determine if program element changes are warranted for the Fit for Performance-Weight Loss Strategies Program. Attrition rates were high, indicating opportunities to research reasons for attendance and attrition in the future. Finally, these findings highlight an opportunity for educating the military leadership on the increased success with increased attendance.

Factors Influencing the Executive Functions of Male and Female Cadets

Executive functions (EFs) are related to human abilities that allow individuals to achieve planned goals, contribute to creativity and the analysis of new ideas, and allow for adaptation to new situations in daily life. Thorough analyses of the factors affecting EFs can aid in the development of appropriate training programs for various social and professional groups, including the military. The purpose of this study was to determine the factors affecting the EFs of cadets (18 women and 108 men) studying at a military academy in Poland after the first and second terms of military training, and to investigate gender differences in the level of EFs, shooting performance (SP), and components of physical fitness (PF). The Neuropsychological Color Trails Test (CTT-2) was used to determine some of the EFs of the test subjects. Meanwhile, the level of SP was represented by the score achieved during marksmanship training implemented during military training. Assessment of the subjects' PF was guided by the principles of the Health-Related Fitness assessment concept, i.e., health-related fitness. Differences between men and women in specific variables were calculated using the Mann-Whitney U test for independent samples, whilst the relationship between variables was analyzed using the best subset regression method. The results revealed that cadets' EFs were influenced by their SP and their level of strength. However, there were no significant differences between male and female cadets in the levels of EFs or SP.

Injury rates in female and male military personnel: a systematic review and meta-analysis

Background

An effective military force is required to be agile, capable, efficient, and potent. Injuries to military personnel interrupt active-duty service and can detract from overall capability. These injuries are associated with a high individual and organizational burden, with lost work time and financial costs—all problematic for the ongoing functioning of a military force. Injury control strategies have therefore been described as force multipliers. Female personnel form an integral part of any modern defence force, but little research has examined their specific experiences of injury, to inform targeted injury control efforts. The aim of this review was to identify and synthesise findings from studies of injury rates and patterns in female military personnel, comparing them to those of male personnel.

Methods

A systematic search was conducted for studies which compared injury rates between the sexes at any stage of military service, from basic training through to deployment. Databases searched included PUBMED, CINAHL and Medline through OVID. Methodological quality of eligible articles was assessed using the Critical Appraisal Skills Program (CASP), and AXIS tools and data were extracted, synthesized, and, where possible, underwent meta-analysis.

Results

Of 2287 identified studies, a total of 25 studies were eligible and included. Methodological quality ranged from 60% up to a perfect score of 100%, with an average of 82% across all studies. Relative risks for injuries (reported as RR [95%CI]) to females when compared to males were 2.10 [1.89–2.33] during basic training, 1.70 [1.33–2.17] during officer training, and 1.23 [1.05–1.43] post initial training. After adjustment for differences between the sexes in average fitness levels (2-mile run time), there was no longer a significant difference in injury rates (adjusted RR: 0.95 [0.86–1.05]). Female personnel tended to make bigger improvements in their fitness during basic training than males and tended to report their injuries more frequently and sooner than males.

Conclusion

While this review found a higher rate of reported injuries in female military personnel when compared to male personnel, differences between the sexes in average fitness levels and injury reporting behaviours may largely explain this rate difference. The difference in rates of reported injuries was greatest during basic training, and reduced thereafter, possibly due in part to a reduced difference in fitness between the sexes or increased opportunity to self-determine workloads relative to fitness levels.

The Relation Between Body Mass Index and Musculoskeletal Injury

Background

The nature and extent of the relation between body mass index (BMI) score and the risk of Musculoskeletal (MSK) injury are still unclear, with few studies investigating. So, the purpose of this study was to assess the association between BMI scores and MSK injury and to see if the site of MSK injury is affected by a specific BMI score. In addition, the risk of MSK injuries was compared among different adult age groups.

Methods

The study population included all patients above 18 years old with musculoskeletal injuries between January 2009 and December 2019 at King Abdulaziz Medical City (KAMC). The estimated sample size was 377. The study subjects were distributed according to their BMI into four categories (underweight, normal weight, overweight, and obese). Also, they were divided according to their age into young adults, middle age, and older adults. Each MSK injury was identified by its location as upper extremity, axial skeleton, or lower extremity. 

Results

Only gender and age were significantly related to the site of injury, with P-values (0.018) and (0.001), respectively. As for the BMI category, its relation with the site of injury was nonsignificant (P-value: 0.092). The younger age group (≤ 35) has a significantly higher chance to be injured in the upper extremities compared with the older adults (≥ 56) (P-value = 0.014). While the axial skeleton (especially the lower back) was the most common site of injury in obese, overweight, and underweight categories, patients with normal BMI have lower extremities as their most common site of injury. 

Conclusion

Although a higher BMI is associated with an increased risk of MSK injury, the difference in the BMI score seems to not effect the site of injury. By contrast, both gender and age group have a significant relationship with the site of MSK injury.

Risk factors for injuries in female soldiers: a systematic review

Background

Female soldiers form an integral part of any modern defence force. Previous reports have highlighted that female soldiers report injuries at higher rates than male personnel. One possible reason for this is an actual difference in underlying injury rates, purported to be due to several factors, including levels of fitness. The aim of this review was to determine risk factors for injuries in female soldiers.

Methods

A systematic search was conducted for studies which reported on risk factors for injuries in female soldiers. Databases searched included PUBMED, CINAHL and Medline through OVID. Eligible studies were rated for their methodological quality using the Critical Appraisal Skills Program (CASP) tools and data were extracted and synthesized using a critical narrative approach.

Results

A total of 18 articles were included in this review which reported on 18 risk factors for injury. Smoking, previous injury, no history of deployment, heavy occupational tasks, lower levels of aerobic fitness and lower number of push-up repetitions appear to be risk factors for injuries in female soldiers. Age, height, body fat, high or low BMI and body mass do not appear to be consistent risk factors for injury in female soldiers and there appears to be minimal evidence for current levels of activity, sit-up ability, and other assessments of strength, power, speed, or movement being associated with injury risk. Additionally, neither flexibility nor previous levels of activity appear to be associated with injury risk in female soldiers.

Conclusion

Strategies to improve aerobic fitness and upper limb endurance, reduce smoking, and optimise rehabilitation from injuries and risk management for heavy occupational tasks need to be developed for female soldiers. Such strategies are also likely to reduce risks for male soldiers.

Prevalence and associated factors of lower extremity musculoskeletal disorders among manufacturing workers: a cross-sectional study in China

OBJECTIVE

To survey the prevalence of lower extremity musculoskeletal disorders (MSDs) among Chinese manufacturing workers, and to identify the associated factors.

DESIGN

Observational study with cross-sectional design.

SETTING

A self-administered questionnaire survey was conducted in four manufacturing factories in China.

PARTICIPANTS

7908 manufacturing workers were included in this study after excluding non-conforming personnel.

OUTCOME MEASURES

Individual and work-related information, and MSDs in the whole leg and knee region were measured by the anonymous self-administered questionnaire. Individual and work-related factors associated with MSDs and their effects were identified through multivariate logistic regression.

RESULTS

Of all respondents, 3241 (41.0%) reported having had lower extremity MSDs in the recent 12 months, and for the knees, ankles/feet and hips/thighs were 29.5%, 23.9% and 16.7%, respectively. After confounder-adjusted single-factor analysis, 22 variables (of 24) were significantly related to the disorders. Factors like always kneeling/squatting for long periods, always standing for long periods and often lifting in an uncomfortable position were shown to have higher risks, with ORs of 2.77 (95% CI: 2.33 to 3.30), 2.30 (1.96 to 2.69) and 2.25 (2.04 to 2.47). Comparable results were found on knee disorders. The final model included 15 variables of demography, biomechanics and work organisation. The following factors showed increased risks of lower extremity MSDs: being female, being older, longer working years, higher body mass index (BMI), keeping the same posture for a long time, awkward position, shift work and monotonous work. Whereas having enough breaks reduced the risk.

CONCLUSION

The prevalence of lower extremity MSDs among Chinese manufacturing workers is high. The most commonly affected body regions were the knees and ankles/feet. Multiple factors were found associated with lower extremity MSDs including age, BMI, work experience, work organisations, physical ergonomics exposures, etc.

Risk factors for musculoskeletal injuries in the military: a qualitative systematic review of the literature from the past two decades and a new prioritizing injury model

BACKGROUND

Musculoskeletal injuries (MSkIs) are a leading cause of health care utilization, as well as limited duty and disability in the US military and other armed forces. MSkIs affect members of the military during initial training, operational training, and deployment and have a direct negative impact on overall troop readiness. Currently, a systematic overview of all risk factors for MSkIs in the military is not available.

METHODS

A systematic literature search was carried out using the PubMed, Ovid/Medline, and Web of Science databases from January 1, 2000 to September 10, 2019. Additionally, a reference list scan was performed (using the "snowball method"). Thereafter, an international, multidisciplinary expert panel scored the level of evidence per risk factor, and a classification of modifiable/non-modifiable was made.

RESULTS

In total, 176 original papers and 3 meta-analyses were included in the review. A list of 57 reported potential risk factors was formed. For 21 risk factors, the level of evidence was considered moderate or strong. Based on this literature review and an in-depth analysis, the expert panel developed a model to display the most relevant risk factors identified, introducing the idea of the "order of importance" and including concepts that are modifiable/non-modifiable, as well as extrinsic/intrinsic risk factors.

CONCLUSIONS

This is the qualitative systematic review of studies on risk factors for MSkIs in the military that has attempted to be all-inclusive. A total of 57 different potential risk factors were identified, and a new, prioritizing injury model was developed. This model may help us to understand risk factors that can be addressed, and in which order they should be prioritized when planning intervention strategies within military groups.

Musculoskeletal Injuries Among Females in the Military: A Scoping Review

INTRODUCTION

Musculoskeletal injuries (MSKi) are a common challenge for those in military careers. Compared to their male peers, reports indicate that female military members and recruits are at greater risk of suffering MSKi during training and deployment. The objectives of this study were to identify the types and causes of MSKi among female military personnel and to explore the various risk factors associated with MSKi.

MATERIALS AND METHODS

A scoping review was conducted over a 4-month time frame of English language, peer-reviewed studies published from 1946 to 2019. Search strategies for major biomedical databases (e.g., MEDLINE; Embase Classic + Embase; and the following EBM Reviews-Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Technology Assessment, and the NHS Economic Evaluation Database) were developed by a senior medical information specialist and included 2,891 titles/abstracts. Study selection and data collection were designed according to the Population, Concept, and Context framework. Studies were included if the study population provided stratified data for females in a military context.

RESULTS

From a total of 2,287 citations captured from the literature searches, 168 peer-reviewed publications (144 unique studies) were eligible for inclusion. Studies were identified from across 10 countries and published between 1977 and 2019. Study designs were primarily prospective and retrospective cohorts. Most studies assessed both prevalence/incidence and risk factors for MSKi (62.50%), with few studies assessing cause (13.69%). For MSKi of female recruits compared to active female members, the prevalence was higher (19.7%-58.3% vs. 5.5%-56.6%), but the incidence (0.02%-57.7% vs. 13.5%-71.9%) was lower. The incidence of stress fractures was found to be much higher in female recruits than in active members (1.6%-23.9% vs. 2.7%). For anthropometric risk factors, increased body fat was a predictor of MSKi, but not stress fractures. For physiological risk factors for both female military groups, being less physically fit, later menarche, and having no/irregular menses were predictors of MSKi and stress fractures. For biomechanical risk factors, among female recruits, longer tibial length and femoral neck diameter increased the risk of stress fractures, and low foot arch increased risk of an ankle sprain. For female active military members, differences in shoulder rotation and bone strength were associated with risk of MSKi. For biological sex, being female compared to male was associated with an increased risk of MSKi, stress fractures, and general injuries. The consequences of experiencing MSKi for active military included limited duties, time off, and discharge. For recruits, these included missed training days, limited duty days, and release.

CONCLUSIONS

This scoping review provides insight into the current state of the evidence regarding the types and causes of MSKi, as well as the factors that influence MSKi among females in the military. Future research endeavors should focus on randomized controlled trials examining training paradigms to see if women are more susceptible. The data presented in the scoping review could potentially be used to develop training strategies to mitigate some of the identified barriers that negatively impact women from pursuing careers in the military.

Musculoskeletal Injuries in US Air Force Security Forces, January 2009 to December 2018

OBJECTIVE

To determine the incidence, types, and risk factors of musculoskeletal injuries in a military security forces population.

METHODS

Demographic and diagnostic data were retrieved on enlisted US Air Force security forces personnel who served on active duty between January 2009 and December 2018. Incidence rates and ratios were calculated using Poisson regression.

RESULTS

During 251,787 person-years of exposure, 62,489 personnel served on active duty. Of these, 40,771 (65.2%) were diagnosed with at least one musculoskeletal injury. The majority (60.1%) of the 164,078 unique musculoskeletal injuries were inflammation and pain secondary to overuse. After adjusting for other factors, women had a 31% higher injury rate than men, and those who were overweight and obese had 15% and 30% higher rates, respectively, than normal-weight peers.

CONCLUSIONS

Modifiable and non-modifiable factors contribute to musculoskeletal injuries in the security forces career field.

Much work remains to reach consensus on musculoskeletal injury risk in military service members: A systematic review with meta-analysis

Musculoskeletal injuries are the most common reason military service members cannot perform their military duties. Not only are they costly and associated with long-term disability, often long after completion of military service, but injuries also adversely affect the military readiness of a nation. This can be seen as a threat to national security and part of the impetus behind many efforts to better understand, predict, and mitigate injury risk in the military. A systematic review of the literature published between 1995 and October 31, 2020 was conducted to identify significant risk factors of musculoskeletal injury in military populations across the world. 74 out of 170 eligible studies addressed comprehensive injuries, providing 994 unique risk factors. 46 of these studies provided data that could be included in a meta-analysis, which was possible for 15 predictor variables. Seven predictors were significant in meta-analysis: female sex(RR=1.46;95CI 1.30,1.64), high body mass index(RR=1.36;95CI 1.21,1.53), functional movement screen pain (RR=1.70;95CI 1.55,1.87) or scores ≤ 14(RR=1.42 95CI 1.29,1.56), prior injury(RR=1.54;95CI 1.32,1.80), slower running performance(RR=1.33;95CI 1.18,1.51), and poorer push-up performance(RR=1.15;95CI 1.04,1.27). Low BMI, height, weight, smoking, physical activity scores, and sit-up and jump performance were not significant risk factors in the meta-analysis. Most studies had a high risk of bias. Lack of raw data and large heterogeneity in definitions of predictors and injury outcomes limited comparison across many studies.Highlights Female sex, high body mass index, pain with functional movement screen or a score of ≤ 14, prior injury, slower running performance and poorer push-up performance were all significant predictors of musculoskeletal injury.Low body mass index, height, weight, smoking, physical activity scores, and sit-up and jump performance were not significant predictors of musculoskeletal injury.Many other predictors were present only in single studies, but large heterogeneity in definitions of both outcomes and predictors limited comparison across studies.Overall, studies assessing risk factors to predict musculoskeletal injuries in the military were at high risk for bias, especially in regards to statistical approaches.

Injury Profile Among Street Workout Practitioners

Background:

Street workout (SW) is an urban sport based on calisthenic exercises. Injury profiles and risk factors are widely explored in various sport disciplines. However, because of the lack of research in SW, injury profiles have not yet been established.

Purpose:

To investigate the characteristics and prevalence of injuries and variables that may increase these odds in SW practitioners.

Study Design:

Case-control study; Level of evidence, 4.

Methods:

An electronic survey was conducted between September 2018 and March 2019 in order to obtain practitioner information, physical activity level, training characteristics, and injury information of SW practitioners. Responses from 93 practitioners were eligible for analysis. Univariate and multivariate binary logistic regression analyses were used to examine the association among several variables and the presence of injury in the past 12 months based on odds ratios (ORs).

Results:

Overall, 62.4% of the 93 participants reported an injury in the previous 12 months, and tendinopathy was the most reported diagnosis (31.0% of injured practitioners). High injury frequency was reported in the shoulder (23.0%) and back (upper and mid) (18.4%). Overtraining was the most reported perception of cause of injury (56.9%). Most injured practitioners (20.7%) performed freestyle exercises before the injury, followed by upper body exercises. A history of previous injuries (OR, 4.078; P = .005) and the middle and higher tertiles of vigorous physical activity (OR, 4.370; P = .015 and OR, 5.634; P = .003, respectively) were associated with a higher odds of injury.

Conclusion:

In SW, the shoulder and back (upper and mid) were the most injured body parts, with tendinopathy being the most frequent diagnosis. Overtraining was typically reported as the perceived cause of injury, with freestyle and upper limb exercises the most performed exercises when injured. A history of previous injuries, along with vigorous physical activity, was found to augment the odds of injury. More research is needed to corroborate our findings, along with increased knowledge about SW practice and injuries.

Factors associated with musculoskeletal injuries in an infantry commanders course

OBJECTIVES

To evaluate the prevalence of injuries among young combat soldiers as assessed and reported by the military physicians, and to investigate whether parameters such as anthropometric measures, postural balance, proprioceptive ability, and chronic ankle instability are related to injuries during and following an infantry commanders course.

METHODS

In this cross-sectional study, 165 soldiers were tested for anthropometric measurements, proprioceptive ability, and dynamic postural balance (DPB), as well as for their responses to an ankle stability questionnaire (CAIT), on three occasions: pre-course, middle-course, and end-course testing. All musculoskeletal injuries were assessed and recorded in the digital medical file of each participant by specialist military physicians before and during/following the course.

RESULTS

Ninety-eight soldiers (59.4%) were injured before the course. Forty soldiers (24.2%) incurred an injury during/following the course (with 33 out of the 40 [82.5%] soldiers that were injured during/following the course having also been injured before the course). Sixty soldiers had no injury before/during/following the course. A survival curve showed that half of the soldiers who were injured during/following the course (20 soldiers) were recorded as injured in the first half of the course (during the first 46 days of the 92-day course). Logistic regression showed that the pre-course parameters that were significant among injured soldiers compared with the non-injured soldiers were: low CAIT results (OR = 2.736, 95% CI = 1.178-6.354), high BMI (OR = 1.234, 95% CI = 1.082-1.406) and reduced proprioceptive ability (OR =.858, 95% CI =.797-.924).

CONCLUSION

With a high prevalence of soldiers injured during and following a commanders course, a somatosensory intervention program should be generalized into the practical daily preparation and training routines of the soldiers for improving somatosensory abilities, optimizing military physical readiness, and for preventing future musculoskeletal injuries.

U.S. Military Veteran Versus Nonveteran Use of Licit and Illicit Substances

INTRODUCTION

To provide up-to-date substance use surveillance data among U.S. military veterans versus nonveterans, this study assesses current use of tobacco products, alcohol, marijuana, prescription pain relievers, tranquilizers, sedatives, stimulants, cocaine, heroin, methamphetamines, inhalants, and hallucinogens.

METHODS

Pooled data were from the 2015-2017 National Survey on Drug Use and Health, a nationally representative, self-reported survey of the U.S. adult non-institutionalized population. Military veterans were those who had "ever been in the United States Armed Forces" and were "now separated/retired from reserves/active duty" (n=7,301). Nonveterans were those who had never been in the U.S. Armed forces (n=121,366). Age- and gender-stratified weighted prevalence estimates were calculated and compared with chi-square tests. All analyses were conducted in 2019.

RESULTS

Illicit substance use, including marijuana and cocaine, was generally lower among veterans than nonveterans, whereas use of licit substances such as tobacco and alcohol was higher among veterans than nonveterans. The most commonly used substances among veterans were tobacco and alcohol. Among male participants aged 18-25 years, 59.8% of veterans reported past-12-month cigarette/cigar smoking (vs 46.6% of nonveterans), whereas 17.6% reported heavy drinking (vs 12.2% of nonveterans). For both cigarette/cigar smoking and binge drinking, there was a marked narrowing of the male-female gap in prevalence with increasing age among veterans. Female veterans aged 18-25 years reported significantly higher opioid use than their nonveteran counterparts (54.7% vs 35.0%); they also had the highest prevalence of opioid misuse (15.3%) than any other group.

CONCLUSIONS

Intensified efforts are needed to reduce substance use among veterans and provide cessation and mental health services.

Incidence of injuries and factors related to injuries in combat soldiers

Introduction

Musculoskeletal injuries to the lower extremities are major factors contributing to drop out from military tasks. The aim of the present study was to determine the incidence of musculoskeletal injuries and the parameters that differentiate between the soldiers who incurred these injuries and those who did not along 14 weeks of an infantry commanders course.

Methods

One-hundred and sixty-eight participants were recruited from an infantry commanders course. The soldiers were tested before (pre), in the middle (middle) and at the end (last) of the course for anthropometric measurements, proprioceptive ability and dynamic postural balance (DPB), and filled out an ankle stability questionnaire (Cumberland Ankle Instability Tool (CAIT). A physiotherapist followed and recorded all musculoskeletal injuries incurred by the participants during the course.

Results

Fifty-eight participants out of the 168 (34.5%) reported some pain/injury. Time effects were found for body mass index, DPB asymmetry, DPB in posterior-medial (P-M) direction and proprioception ability. Injury effects were found for DPB asymmetry, DPB in P-M direction, CAIT and proprioception ability. An interaction was found for proprioception ability. The Cox regression showed that the variables that are mostly effecting injuries were pretesting proprioception ability, DPB asymmetry and CAIT.

Conclusions

More than one out of three participants incurred musculoskeletal injuries, with deficits in proprioception ability, DPB and ankle stability in pretesting as major factors contributing to injuries. Further studies should look at the effect of specific exercises such as proprioception, DPB and ankle stability exercises for prevention and treatment of musculoskeletal injuries among combat soldiers.