A prospective investigation of injury incidence and injury risk factors among Army recruits in military police training

Musculoskeletal complaints and its economic impact in an Iranian army hospital

AIM

Musculoskeletal conditions constitute a remarkable portion of disability cases in the military. This study evaluated the distribution and types of musculoskeletal problems and estimated the direct and indirect costs due to these complaints in an Iranian military hospital.

METHODS

All medical records of patients with musculoskeletal complaints that were referred to the medical committee of a military hospital, including rheumatology, orthopedics, and neuro-surgical specialists, from 2014 to 2016, were reviewed. Details of each complaint and the final opinion of the medical committees were recorded. The cost of each diagnostic step was calculated based on the recorded data. The treatment costs were estimated for each complaint by calculating the average cost of treatment plans suggested by two specialists, a physical medicine and a rheumatologist. The estimated cost for each part is calculated based on the army insurance low. Indirect costs due to absences, inability to work, and disability were assessed and added to the above-mentioned direct costs. Statistical analysis was performed using SPSS version 21.

RESULTS

2,116 medical records of the committee were reviewed. 1252 (59.16%) cases were soldiers (who had to spend two years of mandatory duty in the army), and 864 (40.83%) cases were non-soldiers. The three most common complaints were fractures (301 cases, 14.22%), low back pain due to lumbar disc bulges and herniations (303 cases, 14.31%), and genu varus/genu valgus (257 cases, 12.14%). The most affected sites were the lower limbs and vertebral column. According to an official document in these subjects' records, 4120 person-days absent from work were estimated annually, and nearly $1,172,149 of annual economic impact was calculated.

CONCLUSION

Musculoskeletal problems are common in the army, and establishing preventive strategies for these conditions is essential. The conservative and medical approach and the proper education for correct movement and the situation should be mentioned for the reduction of disability and its economic burden on the army's staff.

Royal Netherlands Marechaussee Personnel's Self-Perceived Occupational Demand Profiles: A Latent Profile Analysis Shows the "Good" Versus the "Bad"

INTRODUCTION

Research has linked high occupational demands to multiple adverse health outcomes, both physical and mental. As far as we know, researchers have not identified the profile characteristics of military police personnel based on occupational demands. The current study aims to identify profiles based on self-perceived occupational demands and work-related factors. This study is a starting point for characterizing performance and health in a military police population.

METHODS

This was a cross-sectional study in which we gathered survey data from 1,135 Royal Netherlands Marechaussee members. We used Latent Profile Analysis to identify profiles based on nine indicators of workload and work characteristics selected via focus groups and interviews with Royal Netherlands Marechaussee personnel. We determined if the profiles differed significantly across all indicators with an analysis of variance. Then, we used binominal logistic regression to determine the odds ratio (OR) for the indicators on profile membership.

RESULTS

We discovered two profiles that were distinct across all indicators. Experience (OR = 1.02, 95% CI [1.00-1.04]), autonomy (OR = 1.18, 95% CI [1.06-1.31]), task clarity (OR = 1.49, [1.32-1.69]), and work support (OR = 2.63, 95% CI [2.26-3.09]) were all predictors for a low perceived occupational demand profile. In contrast, mental (OR = 0.18, 95% CI [0.13-0.25]) and physical (OR = 0.42, 95% CI [0.32-0.54]) fatigue, and boredom (OR = 0.14, 95% CI [0.10-0.20]) were predictors for high perceived occupational demand profiles.

CONCLUSION

We established two distinct profiles that describe the characteristics reported by the Royal Netherlands Marechaussee personnel based on workload and work characteristics. High scores on autonomy, work support, and task clarity predict favorable perceived occupational demands, whereas fatigue and boredom predict unfavorable occupational demands. Remarkably, the physical workload did not predict high perceived occupational demands.

Physiology of Health and Performance: Enabling Success of Women in Combat Arms Roles

INTRODUCTION

The modern female soldier has yet to be fully characterized as she steps up to fill new combat roles that have only recently been opened to women. Both U.S. and U.K. military operational research efforts are supporting a science-based evolution of physical training and standards for female warfighters. The increasing representation of women in all military occupations makes it possible to discover and document the limits of female physiological performance.

METHOD

An informal Delphi process was used to synthesize an integrated concept of current military female physiological research priorities and emerging findings using a panel of subject matter experts who presented their research and perspectives during the second Women in Combat Summit hosted by the TriService Nursing Research Program in February 2021.

RESULTS

The physical characteristics of the modern soldier are changing as women train for nontraditional military roles, and they are emerging as stronger and leaner. Capabilities and physique will likely continue to evolve in response to new Army standards and training programs designed around science-based sex-neutral requirements. Strong bones may be a feature of the female pioneers who successfully complete training and secure roles traditionally reserved for men. Injury risk can be reduced by smarter, targeted training and with attention directed to female-specific hormonal status, biomechanics, and musculoskeletal architecture. An "estrogen advantage" appears to metabolically support enhanced mental endurance in physically demanding high-stress field conditions; a healthy estrogen environment is also essential for musculoskeletal health. The performance of female soldiers can be further enhanced by attention to equipment that serves their needs with seemingly simple solutions such as a suitable sports bra and personal protective equipment that accommodates the female anatomy.

CONCLUSIONS

Female physiological limits and performance have yet to be adequately defined as women move into new roles that were previously developed and reserved for men. Emerging evidence indicates much greater physical capacity and physiological resilience than previously postulated.

Menstrual Function, Eating Disorders, Low Energy Availability, and Musculoskeletal Injuries in British Servicewomen

PURPOSE

This study aimed to investigate associations between menstrual function, eating disorders, and risk of low energy availability with musculoskeletal injuries in British servicewomen.

METHODS

All women younger than 45 yr in the UK Armed Forces were invited to complete a survey about menstrual function, eating behaviors, exercise behaviors, and injury history.

RESULTS

A total of 3022 women participated; 2% had a bone stress injury in the last 12 months, 20% had ever had a bone stress injury, 40% had a time-loss musculoskeletal injury in the last 12 months, and 11% were medically downgraded for a musculoskeletal injury. Menstrual disturbances (oligomenorrhea/amenorrhea, history of amenorrhea, and delayed menarche) were not associated with injury. Women at high risk of disordered eating (Female Athlete Screening Tool score >94) were at higher risk of history of a bone stress injury (odds ratio (OR; 95% confidence interval (CI)), 2.29 (1.67-3.14); P < 0.001) and time-loss injury in the last 12 months (OR (95% CI), 1.56 (1.21-2.03); P < 0.001) than women at low risk of disordered eating. Women at high risk of low energy availability (Low Energy Availability in Females Questionnaire score ≥8) were at higher risk of bone stress injury in the last 12 months (OR (95% CI), 3.62 (2.07-6.49); P < 0.001), history of a bone stress injury (OR (95% CI), 2.08 (1.66-2.59); P < 0.001), a time-loss injury in the last 12 months (OR (95% CI), 9.69 (7.90-11.9); P < 0.001), and being medically downgraded with an injury (OR (95% CI), 3.78 (2.84-5.04); P < 0.001) than women at low risk of low energy availability.

CONCLUSIONS

Eating disorders and risk of low energy availability provide targets for protecting against musculoskeletal injuries in servicewomen.

Injury Profiles of Police Recruits Undergoing Basic Physical Training: A Prospective Cohort Study

Purpose A lack of published epidemiological data among police recruits presents a major challenge when designing appropriate prevention programs to reduce injury burden. We aimed to report the injury epidemiology of Western Australian (WA) Police Force recruits and examine sex and age as injury risk factors. Methods Retrospective analyses were conducted of prospectively collected injury data from WA Police Force recruits between 2018-2021. Injury was defined as 'time-loss' and injury incidence rate per 1000 training days (Poisson exact 95% confidence intervals) was calculated. For each region and type of injury, the incidence, severity, and burden were calculated. The association between age, sex, and injury occurrence were assessed using Cox regression time-to-event analysis. Results A total of 1316 WA Police Force recruits were included, of whom 264 recruits sustained 304 injuries. Injury prevalence was 20.1% and the incidence rate was 2.00 (95%CI 1.78-2.24) injuries per 1000 training days. Lower limb injuries accounted for most of the injury burden. Ligament/ joint injuries had the highest injury tissue/pathology burden. The most common activity injuring recruits was physical training (31.8% of all injuries). Older age (Hazard Ratio = 1.5, 95%CI = 1.2 to 1.9, p = 0.002) and female sex (Hazard Ratio = 1.4, 95%CI = 1.3 to 1.6, p < 0.001) increased risk of injury. Conclusion Prevention programs targeting muscle/tendon and ligament/joint injuries to the lower limb and shoulder should be prioritised to reduce the WA Police Force injury burden. Injury prevention programs should also prioritise recruits who are over 30 years of age or of female sex, given they are a higher risk population.

Association Between Reproductive Health Factors and Musculoskeletal Injuries in Female Canadian Armed Forces Members

Background: Musculoskeletal injuries (MSKi) play a role in member retention in the military. In general, female military members have higher rates of MSKi than males and female reproductive health characteristics may be contributing to these disparities. This study seeks to characterize reproductive health factors in female Canadian Armed Forces (CAF) members and their relationship with MSKi. Materials and Methods: An electronic survey (SurveyMonkey^®) was made available to present and former CAF members 18-65 years of age. Responses were collected between September 2020 and February 2021. Seven female reproductive characteristics were assessed: age of menarche, menstrual cycle regularity, birth control use, having given birth while serving, endometriosis, early menopause, and secondary oligomenorrhea/amenorrhea. Binary logistic regressions were used to analyze associations between reproductive characteristics with repetitive strain (RSI) and acute injuries. Results: A total of 2,001 participants consented to the survey with 855 respondents being female. Females reporting menstrual cycles as never regular, irregular for a few months, who never had a period, and whose periods stopped while serving presented a greater likelihood of reporting RSI compared to their peers who reported regular menstrual cycles (adjusted odds ratio [aOR]: 1.898, confidence interval [CI]: 1.138-3.166). Participants who have experienced endometriosis presented a higher likelihood of reporting acute injuries than those who did not (aOR: 2.426, CI: 1.030-5.709). Conclusion: This examination of females within the CAF suggests that irregular menstrual cycles or absent periods increase the likelihood of experiencing MSKi, namely those categorized as RSI injuries and reporting endometriosis were associated with greater rates of acute injuries.

Prevention of Lower Extremity Musculoskeletal Injuries in Tactical and First Responder Populations: A Systematic Review and Meta-Analysis of Randomized Trials From 1955 to 2020

ABSTRACT

Sinnott, AM, Krajewski, KT, LaGoy, AD, Beckner, ME, Proessl, F, Canino, MC, Nindl, BC, Turner, RL, Lovalekar, MT, Connaboy, C, and Flanagan, SD. Prevention of lower extremity musculoskeletal injuries in tactical and first responder populations: A systematic review and meta-analysis of randomized trials from 1955 to 2020. J Strength Cond Res 37(1): 239-252, 2023-Lower extremity musculoskeletal injuries (LEMSIs) impose a significant burden on tactical and first responder populations. To determine the effectiveness of LEMSI prevention strategies, we performed a systematic review and meta-analysis of randomized controlled trials published in English from 1955 to 2020 (PROSPERO: CRD42018081799). MEDLINE, EMBASE, Cochrane, CINAHL, ProQuest, and DTIC databases were searched for trials that assigned military service members, police, firefighters, or paramedics to LEMSI prevention interventions with a minimum surveillance period of 12 weeks. Evidence was synthesized as odds ratios (OR) for LEMSI occurrence between individuals assigned to interventions and those assigned to standard activities. Risk of bias was assessed with the Cochrane Risk of Bias tool 2.0. Random-effects meta-analyses were conducted for (a) physical training and (b) footwear modifications to reduce LEMSI and (c) footwear modifications to reduce stress fractures specifically. Certainty in the body of evidence was determined with the GRADE approach. Of 28,499 records, 18 trials comprised of more than 11,000 subjects were synthesized. Interventions included physical training (8, N = 6,838), footwear modifications (8, N = 3,792), nutritional supplementation (1, N = 324), and training modifications (1, N = 350). Overall risk of bias was generally moderate ( N = 7 of 18) or high ( N = 9 of 18). Physical training (OR = 0.87, 95% CI [0.71, 1.08], p = 0.22, I 2 = 58.4%) and footwear modification (OR = 1.13, 95% CI [0.85, 1.49], p = 0.42, I 2 = 0.0%) did not reduce LEMSI or stress fractures (OR = 0.76, 95% CI [0.45, 1.28], p = 0.30, I 2 = 70.7%). Our results indicate that there is weak evidence to support current LEMSI prevention strategies. Future efforts will benefit from longer surveillance periods, assessment of women and nonmilitary populations, improved methodological rigor, and a greater breadth of approaches.

Factors Predicting Training Delays and Attrition of Recruits during Basic Military Training

Ensuring a balance between training demands and recovery during basic military training (BMT) is necessary for avoiding maladaptive training responses (e.g., illness or injury). These can lead to delays in training completion and to training attrition. Previously identified predictors of injury and attrition during BMT include demographic and performance data, which are typically collected at a single time point. The aim of this study was to determine individual risk factors for injury and training delays from a suite of measures collected across BMT. A total of 46 male and female recruits undertaking the 12-week Australian Army BMT course consented to this study. Injury, illness, attrition, and demographic data were collected across BMT. Objective measures included salivary cortisol and testosterone, step counts, cardiorespiratory fitness, and muscular endurance. Perceptions of well-being, recovery, workload, fatigue, and sleep were assessed with questionnaires. Baseline and mean scores across BMT were evaluated as predictors of injury and attrition using generalized linear regressions, while repeated-measures ANOVA was used for the group comparisons. From the 46 recruits, 36 recruits completed BMT on time; 10 were delayed in completion or discharged. Multiple risk factors for injury during BMT included higher subjective ratings of training load, fatigue, and stress, lower sleep quality, and higher cortisol concentrations. Higher ratings of depression, anxiety, and stress, and more injuries were associated with a higher risk of delayed completion. Higher concentrations of testosterone and higher levels of fitness upon entry to BMT were associated with reduced risk of injury and delayed completion of BMT. Ongoing monitoring with a suite of easily administered measures may have utility in forewarning risk of training maladaptation in recruits and may complement strategies to address previously identified demographic and performance-based risk factors to mitigate injury, training delays, and attrition.

Profiles of Recruits Entering Army Basic Training in New Zealand

INTRODUCTION

A high incidence of musculoskeletal injuries is sustained by army recruits during basic training. Describing recruits' personal, lifestyle, and physical performance characteristics at the entry to training can help identify existing intrinsic risk factors that may predispose some recruits to injury. Identifying modifiable and preventable intrinsic risk factors may contribute to lower recruit injury and associated burdens during the course of basic training. The aim of this study was to therefore describe the profile of New Zealand Army recruits upon entry to basic training using personal, lifestyle, and physical performance characteristics.

METHODS

New Zealand Army male and female recruits from two intakes in the same year were invited to participate. Recruits' data on personal (sex, age, height, and weight), lifestyle (self-reported responses to the Military Pre-training Questionnaire comprising physical and injury history, diet, alcohol, and smoking status) and physical performance characteristics (2.4-km timed run, weight-bearing dorsiflexion lunge test, and the Y Balance TestTM for lower limb dynamic stability) were collected and analyzed.

RESULTS

Participants included 248 New Zealand Army recruits: 228 males (91.9%), 20 females (8.1%), average age of 20.3 ± 2.8 years. Findings indicated 30.9% of recruits reported injury in the 12 months prior to training commencing, with 44.8% of those injuries in the lower limbs. Pre-entry alcohol consumption was higher than recommended and 20.1% of recruits identified as current smokers. Recruits who passed the 2.4-km timed run included 53.8% of males and 28.6% of females. Weight-bearing dorsiflexion lunge test performance was within a normal range (right = 10.3 ± 3.3 cm), however limb asymmetry (>1.5 cm) was present with 30.9% of recruits. For the Y Balance TestTM for dynamic lower limb stability, 70% of female recruits had high posterolateral reach asymmetry (8.1 ± 6.0 cm), while normalized composite reach scores were low (right) for male (92.2 ± 8.1%) and female recruits (89.0 ± 7.5%).

CONCLUSIONS

New Zealand Army recruits entering basic training were predominantly active young males, reported few injuries in the previous year, had higher than recommended alcohol consumption and a minority were smokers. The majority of recruits had low aerobic fitness, average ankle dorsiflexion range, and low dynamic lower limb stability. While a number of adverse characteristics identified are potentially modifiable, more research is required to identify an association to musculoskeletal injury risk in New Zealand Army recruits. Describing the profile of recruits entering training, particularly recruits at risk of injury is one of the first steps in injury prevention.

Musculoskeletal injury epidemiology in law enforcement and firefighter recruits during physical training: a systematic review

Objectives

Report the injury epidemiology of law enforcement and firefighter recruits.

Design

A systematic epidemiological review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines was completed.

Data sources

Five online databases were searched from database inception to 5 May 2021.

Eligibility criteria for selecting studies

Prospective and retrospective studies that reported data on musculoskeletal injuries sustained by law enforcement or firefighter recruits were included. We reported on all components of injury where data were available. All injury incidence rates were calculated as per 1000 training days (Poisson 95% CI) to allow comparisons between studies. Study quality was assessed using the Joanna Briggs Institute Quality Assessment Checklist for Prevalence Studies.

Results

No studies reporting firefighter recruits were identified. Eight published studies that reported on injuries to law enforcement recruits were identified. The studies were all low quality, and the credibility of the evidence was assessed as very low. Seven studies reported medical attention injuries, and one study reported the number of medical withdrawals from a recruit training programme. The prevalence of law enforcement recruits with medical attention injuries ranged from 13.7% to 24.5%. The overall medical attention injury incidence rate for law enforcement recruits ranged from 1.67 injuries per 1000 training days (Poisson 95% CI 1.00 to 2.34 injuries per 1000 training days) to 4.24 injuries per 1000 training days (Poisson 95% CI 2.97 to 5.51 injuries per 1000 training days).

Conclusion

This review reported the prevalence and incidence rates for musculoskeletal injuries in law enforcement officers. However, the credibility of the evidence is very low.

PROSPERO registration number

CRD42021251084.

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.

Risk Factors for Injuries in Runners: A Systematic Review of Foot Strike Technique and Its Classification at Impact

Background:

It has been suggested that foot strike technique (FST) at initial contact is related to running-related injuries (RRIs).

Purpose:

To explore the relationship between FST and RRIs.

Study Design:

Systematic review; Level of evidence, 3.

Methods:

A systematic electronic search was performed using MEDLINE, PubMed, SPORTDiscus, Scopus, and Web of Science databases. Included were studies published in the English language that explored the relationship between FST and RRIs between January 1960 and November 2020. Results were extracted and collated. The Grading of Recommendations, Assessment, Development and Evaluation approach was applied to synthesize the quality of evidence.

Results:

We reviewed 13 studies exploring the relationship between FST and RRIs. Of these, 6 studies reported FST categorically (foot strike pattern [FSP]), and 7 reported continuous measures (foot contact angle, ankle flexion angle, and strike index). Three of the 6 studies looking at categorical FSP found rearfoot strikers have a significantly greater retrospective injury rate than do non– rearfoot strikers, with 1 other study noting a greater risk associated with midfoot and forefoot strike. Regarding the continuous measures of FST, only 1 of the 7 studies reported a significant relationship with RRIs.

Conclusion:

There was low evidence to suggest a relationship between FST (or its subcategories of categorical FSP and continuous measures) and RRIs. While two-thirds of the categorical studies found a relationship between FSP and RRIs, these studies were very low quality, with limitations such as retrospective study design, low participant numbers, and poor FSP assessment methods. More large-scale prospective studies are required.

Feeding female soldiers: Consideration of sex-specific nutrition recommendations to optimise the health and performance of military personnel

Appropriate nutrition recommendations are required to optimise the health and performance of military personnel, yet limited data are available on whether male and female military personnel have different nutrition requirements.

OBJECTIVES

To consider the evidence for sex-specific nutrition requirements to optimise the health and performance of military personnel.

DESIGN

Narrative review.

METHODS

Published literature was reviewed, with a focus on sex-specific requirements, in the following areas: nutrition for optimising muscle mass and function, nutrition during energy deficit, and nutrition for reproductive and bone health.

RESULTS

There are limited data on sex differences in protein requirements but extant data suggest that, despite less muscle mass, on average, in women, sex-specific protein feeding strategies are not required to optimise muscle mass in military-aged individuals. Similarly, despite sex differences in metabolic and endocrine responses to energy deficit, current data do not suggest a requirement for sex-specific feeding strategies during energy deficit. Energy deficit impairs health and performance, most notably bone and reproductive health and these impairments are greater for women. Vitamin D, iron and calcium are important nutrients to protect the bone health of female military personnel due to increased risk of stress fracture.

CONCLUSIONS

Women have an increased incidence of bone injuries, less muscle mass and are more susceptible to the negative effects of energy deficit, including compromised reproductive health. However, there are limited data on sex differences in response to various nutrition strategies designed to improve these elements of health and performance. Future studies should evaluate whether sex-specific feeding recommendations are required.

Battery Fitness Testing in Law Enforcement: A Critical Review of the Literature

Police trainees undergoing training to prepare them for the occupational demands of policing are often subjected to fitness testing. The aim of this review was to critically appraise research studies employing police fitness tests.

METHOD

A comprehensive search of four databases (PubMed, EMBASE, and Ebscohost [CINAHL and SportDiscus]) was conducted by two authors independently. After duplicate articles were removed, articles that did not meet the pre-determined inclusion criteria and met the exclusion criteria were removed. The remaining studies were critically appraised by two authors independently using a Downs and Black Checklist. Cohen's Kappa coefficient was used to measure the level of agreement between appraisers and calculated by a third author. The grading system proposed by Kennelly was used to grade the methodological quality of the studies.

RESULTS

From an initial 7384 identified studies, including four from additional sources, 11 studies met the criteria for review. The mean critical appraisal score for the articles was 74.36 (± 1.48%) being considered 'good' quality and a 'substantial' level of agreement was found between the two appraisers (k = 0.75). The most common measures assessed were muscle endurance (push-ups and sit-ups) and aerobic capacity (running), with the least common measure being agility. Assessments of push-ups and the 2.4-km (1.5-mile) run had the strongest correlations to law enforcement academy graduation across the studies. Grip strength may predict occupational performance (marksmanship) as well as longevity.

CONCLUSION

The push-up and 2.4 km (1.5-mile) run fitness tests were the most popular fitness assessments and had the strongest positive correlation to law enforcement academy graduation.

Profiling the Injuries Sustained by Police Trainees Undergoing Initial Training: A Retrospective Cohort Study

The tasks performed by police officers are unique, varied and can be performed in unexpected situations. Initial police college training is used to prepare new police officers to conduct these tasks and is known to be a time when police trainees are at an elevated risk of injury. The aim of this study was to profile injuries occurring within a national Police Force during initial training to inform injury prevention strategies. Using a retrospective cohort design, point-of-care injury data including injury body site, nature, mechanism, and the activity being performed at the time of injury were provided. A total of 564 injuries were recorded over the 22-month period, with the mean age of recruits reporting an injury being 28.83 years ± 6.9 years. The incidence of injuries ranged across training periods, from 456.25 to 3079 injuries per 1000 person-years with an overall incidence rate of 1550.15 injuries per 1000 person-years. The shoulder was the most injured site (n = 113, 20% of injuries), with sprains and strains being the most common nature of injury (n = 287, 50.9% of injuries). Muscular stress with physical exercise was the most common mechanism of injury (n = 175, 31.0% of injuries) with the activity responsible for the largest proportion of injuries being “unknown” (n = 256, 45.4% of injuries), followed by police training (n = 215, 38.1%). Injuries appear to be typically joint related—commonly the shoulder—with police training being a primary known activity at the time of injury. Prescreening protocols may be of benefit, and efforts should be made to recruit and train physically resilient trainees. Injuries, whether they occurred pre-enlistment or during training, should be fully rehabilitated prior to the individual’s commencement as a qualified officer.

Prevalence of Musculoskeletal Injuries in New Zealand Army Recruits as Defined by Physical Therapy Service Presentations

INTRODUCTION

Army recruit injuries occurring during basic training can lead to high personal and organizational burdens potentially threatening deployment capability. Previous military surveillance describing recruit injury as defined by physical therapy presentations is limited to 1-year duration or includes only male infantry recruits or trained personnel. Research describing injury incidence and trends specific to New Zealand Army basic training recruits over a longer period will better inform future injury prevention programs.

AIMS

To identify the incidence and patterns of injuries reported from physical therapy presentations for New Zealand Army recruits undertaking basic training over a 4-year period.

MATERIALS AND METHODS

This retrospective observational study identified injuries from physical therapy service presentations in New Zealand Army recruits from 2008 to 2011. All male and female New Zealand Army recruits who presented to physical therapy, following medical triage, were included. Recruit physical therapy presentations for injury and respiratory and other conditions were collated. Injury incidence was grouped by body region (upper limbs, lower limbs, and combined spinal regions) and site (joint or segment), and cumulative and injury incidence rates were calculated.

RESULTS

One thousand eight hundred and ninety-six (1,697 males and 199 females) New Zealand Army recruits commenced basic training between 2008 and 2011. One thousand six hundred and eighty-three physical therapy presentations occurred for recruit injury during New Zealand Army basic training over 4 years. Lower limb injuries accounted for over 75% (n = 1,285) of the overall demand for physical therapy service during recruit basic training. Injuries sustained at the knee and below accounted for 67% of all reported injury presentations.

CONCLUSION

Four years of injury surveillance using physical therapy presentations identified the lower limb, with the knee and below as the most commonly injured regions in New Zealand Army recruits. Injury prevention interventions for New Zealand Army recruits should aim to reduce lower limb injuries. Future research on injury surveillance would benefit from incorporating clear injury and severity definitions, established injury classification systems, and standardized incidence calculations.

Injury Incidence Across the Menstrual Cycle in International Footballers

Objectives: This study aimed to assess how menstrual cycle phase and extended menstrual cycle length influence the incidence of injuries in international footballers.

Methods: Over a 4-year period, injuries from England international footballers at training camps or matches were recorded, alongside self-reported information on menstrual cycle characteristics at the point of injury. Injuries in eumenorrheic players were categorized into early follicular, late follicular, or luteal phase. Frequencies were also compared between injuries recorded during the typical cycle and those that occurred after the cycle would be expected to have finished. Injury incidence rates (per 1,000 person days) and injury incidence rate ratios were calculated for each phase for all injuries and injuries stratified by type.

Results: One hundred fifty-six injuries from 113 players were eligible for analysis. Injury incidence rates per 1,000 person-days were 31.9 in the follicular, 46.8 in the late follicular, and 35.4 in the luteal phase, resulting in injury incidence rate ratios of 1.47 (Late follicular:Follicular), 1.11 (Luteal:Follicular), and 0.76 (Luteal:Late follicular). Injury incident rate ratios showed that muscle and tendon injury rates were 88% greater in the late follicular phase compared to the follicular phase, with muscle rupture/tear/strain/cramps and tendon injuries/ruptures occurring over twice as often during the late follicular phase compared to other phases 20% of injuries were reported as occurring when athletes were “overdue” menses.

Conclusion: Muscle and tendon injuries occurred almost twice as often in the late follicular phase compared to the early follicular or luteal phase. Injury risk may be elevated in typically eumenorrheic women in the days after their next menstruation was expected to start.

Nonexercise Interventions for Prevention of Musculoskeletal Injuries in Armed Forces: A Systematic Review and Meta-Analysis

CONTEXT

This study evaluates the effect of nonexercise interventions on the reduction of risk for musculoskeletal injuries in armed forces.

EVIDENCE ACQUISITION

A database search was conducted in PubMed/MEDLINE, Embase, Cochrane Library, CINAHL, SPORTdiscus, Greylit, Open Grey, the WHO trial registry, and the reference lists of included articles up to July 2019. RCTs and cluster RCTs evaluating nonexercise interventions for the prevention of musculoskeletal injuries in armed forces compared with any other intervention(s) or no intervention were eligible for inclusion. Data extraction and risk of bias assessment were done by 2 authors independently, followed by meta-analysis and Grading of Recommendations Assessment, Development, and Evaluation assessment, if appropriate.

EVIDENCE SYNTHESIS

This study included 27 articles with a total number of 25,593 participants, examining nutritional supplementation, prophylactic medication, and equipment modifications with mostly high or unclear risk of bias. Meta-analysis and Grading of Recommendations Assessment, Development, and Evaluation assessment could be performed for 3 comparisons: custom-made insoles versus no insoles, tropical/hot-weather boots versus leather boots, and shock-absorbing insoles versus nonshock-absorbing insoles interventions, all showing the very low quality of evidence. Some evidence was found to support the preventive effect of shock-absorbing insoles, basketball shoes, padded polyester socks, calcium with vitamin D supplementation, only calcium supplementation, protein supplementation, and dynamic patellofemoral braces.

CONCLUSIONS

Although an evidence base for the efficacy of preventive interventions for musculoskeletal injuries in armed forces is weak, there are some indications for the preventive effect of shock-absorbing insoles, basketball shoes, padded polyester socks, supplementation of calcium alone or combined with vitamin D, protein supplementation, and dynamic patellofemoral braces on the incidence of musculoskeletal injuries.

Trunk endurance, posterior chain flexibility, and previous history of musculoskeletal pain predict overuse low back and lower extremity injury: a prospective cohort study of 545 Navy Cadets

OBJECTIVE

To investigate predictors of low back and lower extremity musculoskeletal injury in a cohort of Naval cadets.

DESIGN

Prospective Cohort Study METHODS: 545 Naval cadets (Males, n = 394, 72%) were followed-up over eight months. Nine variables were investigated as predictors: history of musculoskeletal symptoms in the last 12 months, ankle dorsiflexion range of motion, sit and reach test, isometric hip abduction and external rotation strength, alignment during the single leg squat test, single leg hop test for distance, prone plank and side plank tests. All injuries that required medical attention were registered. Predictive associations were examined using univariable and multivariable logistic regression analyses.

RESULTS

The incidence of all injuries was 7%. Cadets who failed the 60-second plank test (OR = 3.3; 95% CI, 1.2-8.8, P = 0.04), had ≤18 cm in the sit and reach test (OR = 4.0; 95% CI, 1.4-11.2, P = 0.01), or reported pain in the last 12 months in two or more body regions (OR = 2.7; 95% CI, 1.02-7.3, P = 0.04), had greater odds of sustaining an overuse injury. No predictors were identified for acute injuries.

CONCLUSION

Decreased trunk endurance on the prone plank test, reduced posterior chain flexibility on the sit and reach test, and a history of pain reported in two or more sites in the last 12 months were predictors of overuse injuries in Naval cadets. Assessment and intervention of these modifiable risk factors may be clinically relevant in injury screening and prevention.

Energy Deficiency in Soldiers: The Risk of the Athlete Triad and Relative Energy Deficiency in Sport Syndromes in the Military

Military personnel experience energy deficit (total energy expenditure higher than energy intake), particularly during combat training and field exercises where exercising energy expenditures are high and energy intake is reduced. Low energy availability (energy intake minus exercising energy expenditure expressed relative to fat free mass) impairs endocrine function and bone health, as recognized in female athletes as the Female Athlete Triad syndrome. More recently, the Relative Energy Deficiency in Sport (RED-S) syndrome encompasses broader health outcomes, physical and cognitive performance, non-athletes, and men. This review summarizes the evidence for the effect of low energy availability and energy deficiency in military training and operations on health and performance outcomes. Energy availability is difficult to measure in free-living individuals but doubly labeled water studies demonstrate high total energy expenditures during military training; studies that have concurrently measured energy intake, or measured body composition changes with DXA, suggest severe and/or prolonged energy deficits. Military training in energy deficit disturbs endocrine and metabolic function, menstrual function, bone health, immune function, gastrointestinal health, iron status, mood, and physical and cognitive performance. There are more data for men than women, and little evidence on the chronic effects of repeated exposures to energy deficit. Military training impairs indices of health and performance, indicative of the Triad and RED-S, but the multi-stressor environment makes it difficult to isolate the independent effects of energy deficiency. Studies supplementing with energy to attenuate the energy deficit suggest an independent effect of energy deficiency in the disturbances to metabolic, endocrine and immune function, and physical performance, but randomized controlled trials are lacking.

Medical Encounters During the United States Army Special Forces Assessment and Selection Course

Introduction

The Special Forces Assessment and Selection (SFAS) is an extremely physically and mentally demanding 19- to 20-day course designed to determine whether Soldiers are qualified to enter the Special Forces Qualification Course. As a first step to understand medical problems during SFAS, this study examined injuries, illnesses, and activities associated with injuries during the course.

Materials and Methods

Medical events during the SFAS course were compiled from Sick Call Trackers (a log of medical encounters maintained by medical personnel in the field) and Chronology of Medical Care (Standard Form 600). Descriptive statistics were calculated for each injury and illness and injuries were compiled by the activities performed when the injuries occurred.

Results

Of the 800 Soldiers who volunteered for the study, 38% (n = 307/800) and 12% (n = 97/800) experienced one or more injuries and/or illnesses, respectively. The most common injuries were blisters and abrasions/lacerations with incidences of 20% (n = 158/800) and 13% (104/800), respectively. The most common illnesses were respiratory infections, other infections, contact dermatitis, and allergies with incidences of 7% (n = 57/800), 2% (n = 14/800), 2% (n = 14/800), and 2% (n = 13/800), respectively. Among all injuries recorded (n = 573), the most common were blisters (46%), abrasions/lacerations (24%), pain (not otherwise specified) (19%), tendonitis (3%), and sprains (3%). Among all illnesses recorded (n = 133), the most common were respiratory infections (56%), allergies (11%), contact dermatitis (11%), and other infections (11%). Most injuries were experienced during land navigation (44%), team events (20%), and foot marching (11%), running (6%), and the obstacle course (5%), but when the estimated time involved for each event was considered, activities with the highest injury rates were the obstacle course (65 injuries/hr), running (27 injuries/hr), the Combat Readiness Assessment (activity involving combat-related tasks) (20 injuries/hr), and foot marching (16 injuries/hr).

Conclusion

The major limitations of this investigation were: 1) the low specificity with regard to many of the diagnoses/complaints; and 2) the fact that the medical problems reported here are only those seen by medical care providers and are likely an underestimate of the total morbidity in the SFAS course. Soldiers often self-treat and some may be reluctant to see medical personnel because of how it might affect their rating in the course. Nonetheless, this investigation alerts medical personnel to the injuries and illnesses to expect, and public health workers and leadership with activities to target for injury prevention measures during SFAS.

Exercise Programs to Reduce the Risk of Musculoskeletal Injuries in Military Personnel: A Systematic Review and Meta-Analysis

Objective

To evaluate the effect of exercise programs on reduction of musculoskeletal injury (MSI) risk in military populations.

Design

Systematic review and meta‐analysis.

Literature Survey

A database search was conducted in PubMed/MEDLINE, EMBASE, Cochrane Library, CINAHL, SPORTdiscus, WHO International Clinical Trials Registry Platform Search Portal, Open Gray, National Technical Reports Library, and reference lists of included articles up to July 2019. Randomized and cluster‐randomized controlled trials evaluating exercise programs as preventive interventions for MSIs in armed forces compared to other exercise programs or to usual practice were eligible for inclusion.

Methodology

Two authors independently assessed risk of bias and extracted data. Data were adjusted for clustering if necessary and pooled using the random‐effects model when appropriate.

Synthesis

We included 15 trials in this review, with a total number of 14 370 participants. None of the included trials appeared to be free of any risk of bias. Meta‐analysis and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) assessment could be performed for static stretching compared to no stretching (3532 participants), showing low quality of evidence indicating no favorable effect of stretching. Gait retraining, an anterior knee‐pain targeted program, and resistance exercises showed cautious favorable effects on reducing injury risk in military personnel.

Conclusion

The current evidence base for exercise‐based MSI prevention strategies in the military is of low quality. Areas worthy of further exploration include the effects of gait retraining, anterior knee‐pain targeted programs, agility training, and resistance training programs, on medial tibial stress syndrome incidence, anterior knee pain incidence, attrition due to injuries and any type of MSI, respectively.

Risk of Injury in Royal Air Force Training: Does Sex Really Matter?

INTRODUCTION

Musculoskeletal injuries are common during military and other occupational physical training programs. Employers have a duty of care to reduce employees' injury risk, where females tend to be at greater risk than males. However, quantification of principle co-factors influencing the sex-injury association, and their relative importance, remain poorly defined. Injury risk co-factors were investigated during Royal Air Force (RAF) recruit training to inform the strategic prioritization of mitigation strategies.

MATERIAL AND METHODS

A cohort of 1,193 (males n = 990 (83%); females n = 203 (17%)) recruits, undertaking Phase-1 military training, were prospectively monitored for injury occurrence. The primary independent variable was sex, and potential confounders (fitness, smoking, anthropometric measures, education attainment) were assessed pre-training. Generalized linear models were used to assess associations between sex and injury.

RESULTS

In total, 31% of recruits (28% males; 49% females) presented at least one injury during training. Females had a two-fold greater unadjusted risk of injury during training than males (RR = 1.77; 95% CI 1.49-2.10). After anthropometric, lifestyle and education measures were included in the model, the excess risk decreased by 34%, but the associations continued to be statistically significant. In contrast, when aerobic fitness was adjusted, an inverse association was identified; the injury risk was 40% lower in females compared with males (RR = 0.59; 95% CI: 0.42-0.83).

CONCLUSIONS

Physical fitness was the most important confounder with respect to differences in males' and females' injury risk, rather than sex alone. Mitigation to reduce this risk should, therefore, focus upon physical training, complemented by healthy lifestyle interventions.

Functional Movement Screen (FMS™) Scores and Demographics of US Army Pre-Ranger Candidates

Introduction

The United States Army Rangers are a unique population whose training requirements are intensive, and physically and mentally demanding. The Functional Movement Screen (FMS) is a movement screening tool designed to assess movement quality and asymmetries in movement with the potential to identify injury risk. This study was a descriptive, cross-sectional investigation examining associations between FMS scores and the various measures of health and performance of active duty soldiers in light infantry units who were involved in the U.S. Army Pre-Ranger Course (PRC).

Materials and Methods

Before the PRC, 491 male soldiers (mean age = 24.0 ± 3.8 years; mean height = 176.6 ± 7.2 cm; mean body mass = 80.2 ± 9.8 kg) completed a questionnaire which included items on self-assessed physical fitness, last Army physical fitness test (APFT) score, tobacco use, and injury history. The soldiers then completed the FMS, which consisted of seven movements and three clearing tests. From the FMS results, a determination of asymmetries (i.e., differences in FMS scores between the right and left side of the body) was made. Differences between groups were analyzed via an independent sample t-test, a one-way analysis of variance, or a chi-square as appropriate. Significance was set at 0.05 a priori.

Results

The average composite FMS score was 16.4 (±1.9) points. Soldiers reporting ≥290 APFT points achieved a higher FMS score than those reporting lower APFT scores (16.5 ± 2.0 vs 16.1 ± 2.0 points, P = 0.03). Soldiers reporting either tobacco use or a previous musculoskeletal injury had lower FMS scores than those not reporting these (tobacco: 16.1 ± 2.1 vs 16.5 ± 1.8 points, P = 0.02; injury: 16.0 ± 2.2 vs 16.6 ± 1.8 points, P &lt; 0.01). FMS asymmetries were not related to APFT scores, tobacco use, or self-rated fitness. As self-rated fitness increased so did APFT scores.

Conclusions

Active duty soldiers of a light infantry division achieved FMS scores similar to other military populations tested, and the composite FMS score was related to higher APFT scores, absence of tobacco use, and absence of previous musculoskeletal injuries. Improving PRC candidate healthy habits through highlighting the negative associations between poorer fitness, cigarette tobacco use and movement quality, may reduce injury risk and increase PRC completion potential.

A longitudinal observational study of back pain incidence, risk factors and occupational physical activity in Swedish marine trainees

OBJECTIVES

To evaluate the occurrence of low back pain (LBP) and LBP that limits work ability, to identify their potential early risks and to quantify occupational physical activity in Swedish Armed Forces (SwAF) marines during their basic 4 month marine training course.

DESIGN

Prospective observational cohort study with weekly follow-ups.

PARTICIPANTS

Fifty-three SwAF marines entering the training course.

OUTCOMES

Incident of LBP and its related effect on work-ability and associated early risks. Occupational physical activity, as monitored using accelerometers and self-reports.

RESULTS

During the training course, 68% of the marines experienced at least one episode of LBP. This yielded a LBP and LBP limiting work ability incidence rate of 13.5 (95% CI 10.4 to 17.8) and 6.3 (95% CI 4.2 to 10.0) episodes per 1000 person-days, respectively. Previous back pain and shorter body height (≤1.80 m) emerged as independent risks for LBP (HR 2.5, 95% CI 1.4 to 4.3; HR 2.0, 95% CI 1.2 to 3.3, respectively), as well as for LBP that limited work ability (HR 3.6, 95% CI 1.4 to 8.9; HR 4.5, 95% CI 2.0 to 10.0, respectively). Furthermore, managing fewer than four pull-ups emerged as a risk for LBP (HR 1.9, 95% CI 1.2 to 3.0), while physical training of fewer than three sessions per week emerged as a risk for LBP that limited work ability (HR 3.0, 95% CI 1.2 to 7.4). More than 80% of the work time measured was spent performing low levels of ambulation, however, combat equipment (≥17.5 kg) was carried for more than half of the work time.

CONCLUSIONS

Incidents of LBP are common in SwAF marines' early careers. The link between LBP and previous pain as well as low levels of exercise highlights the need for preventive actions early on in a marine's career. The role of body height on LBP needs further investigation, including its relationship with body-worn equipment, before it can effectively contribute to LBP prevention.

Injury Occurrence and Return to Dance in Professional Ballet: Prospective Analysis of Specific Correlates

Professional ballet is a highly challenging art, but studies have rarely examined factors associated with injury status in ballet professionals. This study aimed to prospectively examine gender-specific correlates of injury occurrence and time-off from injury in professional ballet dancers over a one-year period. The participants were 99 professional ballet dancers (41 males and 58 females). Variables included: (i) predictors: sociodemographic data (age, educational status), ballet-related factors (i.e., experience in ballet, ballet status), cigarette smoking, alcohol drinking, and consumption of illicit drugs; and (ii) outcomes: injury occurrence and time-off from injury. Participants were questioned on predictors at the beginning of the season, while data on outcomes were collected continuously once per month over the study period. Dancers reported total of 196 injuries (1.9 injuries (95% CI: 1.6–2.3) per dancer in average), corresponding to 1.4 injuries per 1000 dance-hours (95% CI: 1.1–1.7). In females, cigarette smoking was a predictor of injury occurrence in females (OR: 4.33, 95% CI: 1.05–17.85). Alcohol drinking was a risk factor for absence from dance in females (OR: 1.29, 95% CI: 1.01–4.21) and males (OR: 1.21, 95% CI: 1.05–3.41). Less experienced dancers were more absent from dance as a result of injury than their more experienced peers (Mann-Whitney Z: 2.02, p < 0.04). Ballet dancers and their managers should be aware of the findings of this study to make informed decisions on their behavior (dancers) or to initiate specific programs aimed at the prevention of substance use and misuse in this profession (managers).

Gender differences in limited duty time for lower limb injury

Background

Among active-duty military personnel, lower limb musculoskeletal injuries and related conditions (injuries) frequently arise as unintended consequences of physical training. These injuries are particularly common among women. The practical impact of such injuries on temporary military occupational disability has not been estimated with precision on a large scale.

Aims

To determine the proportion of service time compromised by limited duty days attributable to lower limb injuries, characterize the time affected by these limitations in terms of specific lower limb region and compare the limited duty time between male and female soldiers.

Methods

Administrative data and individual limited duty assignments (profiles) were obtained for active-duty US Army personnel who served in 2014. Lower limb injury-related profiles were used to calculate the percent of person-time requiring duty limitations by gender and body region.

Results

The study group was 568 753 soldiers of whom 14% were women. Nearly 13% of service days for active-duty US Army soldiers required limited duty for lower limb injuries during 2014. Knee injuries were responsible for 45% of those days. Within integrated military occupations, female soldiers experienced 27-57% more time on limited duty for lower limb injuries compared with men.

Conclusions

The substantial amount of limited duty for lower limb musculoskeletal injuries among soldiers highlights the need for improvement in training-related injury screening, prevention and timely treatment with particular attention to knee injuries. The excessive impact of lower limb injuries on female soldiers' occupational functions should be a surveillance priority in the current environment of expanding gender-integrated training.

Prediction of exertional lower extremity musculoskeletal injury in tactical populations: protocol for a systematic review and planned meta-analysis of prospective studies from 1955 to 2018

BACKGROUND

Musculoskeletal injuries (MSI) represent more than half of all injuries in tactical populations (i.e., military service and public safety workers including police, firefighters, emergency medical services (EMS)). Most lower extremity MSIs result from physical exertion during training, occupational tasks, and recreation. Such exertional lower extremity injuries (ELEI) produce a significant human and financial cost. Accordingly, significant efforts have been made to identify sensitive, specific, and reliable predictors of ELEI. There is a need to synthesize and evaluate the predictive value of risk factors for ELEI while addressing the influence of occupation, sex, exposure, injury characteristics, and study quality. Therefore, the purpose of this systematic review and planned meta-analysis is to evaluate risk factors for ELEI in tactical populations.

METHODS

After the development of a search strategy, comprehensive searches will be conducted in MEDLINE, EMBASE, Cochrane, and CINAHL databases. Articles will be screened with a multi-user process and delimited to prospective comparative cohort studies that directly measure injury occurrence in the target population(s). Extracted data will be synthesized and assessed for reporting bias, meta-bias, and overall quality, with subgroup analyses to determine the influence of participant, injury, and exposure characteristics in addition to study quality.

DISCUSSION

This systematic review and planned meta-analysis will comprehensively evaluate ELEI risk factors. Information gained will inform injury prevention protocols, facilitate the use of improved measurements, and identify requirements for future research.

TRIAL REGISTRATION

The systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 3 Jan 2018 (registration number CRD42018056977 ).

Injury Surveillance and Reporting for Trainees with Bone Stress Injury: Current Practices and Recommendations

Background

Musculoskeletal injuries, including lower extremity bone stress injuries (BSI) significantly impact initial entry training (IET) in the U.S. Army due to limited duty days, trainee attrition, early medical discharge, and related financial costs. Factors complicating trainee BSI surveillance include inconsistent BSI coding practices, attrition documentation as both administrative separations and medical discharges and the inability to code for BSI grade or severity when using International Statistical Classification of Diseases and Related Health Problems 10th revision (ICD-10) codes.

Methods

A multidisciplinary expert panel developed policy guidance to enhance clinical and administrative management of BSI, following extensive analysis of current, peer-reviewed literature. Policy guidance incorporates leading practices concerning clinical BSI management, including imaging procedures, recommended notifications, early intervention, and ICD-10 diagnostic coding procedures. Policy guidance also standardizes BSI grading criteria for magnetic resonance imaging and skeletal scintigraphy (bone scan).

Findings

Multidisciplinary expert opinion indicates inconsistent BSI diagnosis and management across IET due to variability in trainee BSI grading, documentation, and coding practices. Injury surveillance conducted by the United States Army Medical Command (USAMEDCOM) will benefit from routine, standardized musculoskeletal injury data base searches by BSI severity/grade and anatomical location upon implementation of BSI policy guidance.

Discussion

Effective injury surveillance is critical for determining trainee BSI incidence and attrition, developing anticipated return to duty (RTD) timelines, and assessing long-term outcomes. BSI RTD timelines should account for gender, BSI grade/severity, anatomical location, and type of intervention. Well-defined RTD timelines would benefit administrative decision-making purposes, including whether to grant convalescent leave or enroll in the Warrior Training and Rehabilitation Program during BSI recovery. Enhanced management procedures may improve initial enlistment completion rates for trainees sustaining at least one BSI who eventually complete IET.

Incidence of Musculoskeletal Injury in US Army Unit Types: A Prospective Cohort Study

BACKGROUND

Musculoskeletal injuries during military service are a primary source of disability, resulting in 2.4 million annual health care visits and 25 million limited-duty days. While the injury incidence during basic training is well documented, there is little understanding of injury distribution by organization type in the US Army following initial training.

OBJECTIVE

To compare injury incidence, distribution, and impact across various military units.

METHODS

In this prospective observational cohort study, comprehensive injury data from subject questionnaires and medical chart reviews were collected over 12 months for 1430 initially healthy Army personnel, representing combat, combat support, combat service support, and ranger units. Health care utilization and time loss due to injury were also collected.

RESULTS

Of 1430 soldiers, 481 (33.6%) had time-loss injury, 222 (15.5%) were injured without limited work, 60 (4.2%) reported an injury but did not seek medical care, and 667 (46.6%) were uninjured. Across the whole sample, injuries were responsible for 5.9 ±14.4 medical visits per soldier, 21 902 days of limited work, and $1 337 000 ($1901 ± $6535 per soldier) in medical costs. Considering only those reporting injury, each person averaged 36.3 ± 59.7 limited-work days. The injury incidence was highest in combat service support units (65.6%), with a risk ratio 1.60 times that of the reference group (combat, 41.1%).

CONCLUSION

Combat support and combat service support personnel were more likely to have 1 or more injuries compared to rangers and combat personnel. The higher relative risk of injury in support units should be explored further. J Orthop Sports Phys Ther 2018;48(10):749-757. Epub 22 May 2018. doi:10.2519/jospt.2018.7979.

Dynamic Movement Assessment and Functional Movement Screening for injury prediction: a systematic review

ABSTRACT Dynamic Movement AssessmentTM (DMATM) and Functional Movement ScreeningTM (FMSTM) are tools to predict the risk of musculoskeletal injuries in individuals who practice physical activities. This systematic review aimed to evaluate the association of DMATM and FMSTM with the risk of musculoskeletal injuries, in different physical activities, categorizing by analysis. A research without language or time filters was carried out in November 2016 in MEDLINE, Google Scholar, SciELO, SCOPUS, SPORTDiscus, CINAHL and BVS databases using the keywords: “injury prediction”, “injury risk”, “sensitivity”, “specificity”, “functional movement screening”, and “dynamic movement assessment”. Prospective studies that analyzed the association between DMATM and FMSTM with the risk of musculoskeletal injuries in physical activities were included. The data extracted from the studies were: participant’s profile, sample size, injury’s classification criteria, follow-up time, and the results presented, subdivided by the type of statistical analysis. The risk of bias was performed with Newcastle-Ottawa Scale for cohort studies. No study with DMATM was found. A total of 20 FMSTM studies analyzing one or more of the following indicators were included: diagnostic accuracy (PPV, NPV and AUC), odds ratios (OR) or relative risk (RR). FMSTM showed a sensitivity=12 to 99%; specificity=38 to 97%; PPV=25 to 91%; NPV=28 to 85%; AUC=0.42 to 0.68; OR=0.53 to 54.5; and RR=0.16-5.44. The FMSTM has proven to be a predictor of musculoskeletal injuries. However, due to methodological limitations, its indiscriminate usage should be avoided.

The incidence of military training-related injuries in Chinese new recruits: a systematic review and meta-analysis

INTRODUCTION

Training-related injuries are the main reason for disability, long-term rehabilitation, functional impairment and premature discharge from military service. The aim of this study was to identify the incidence of injuries in the training of Chinese new recruits via a systematic review of the literature.

METHOD

A systematic review and meta-analysis was conducted to evaluate the combined incidence of military training-related injuries in Chinese new recruits. The electronic databases of full-text journals were searched, and the Loney criteria were used to assess the quality of eligible articles. Summary estimates were obtained using random-effects models. Subgroup analyses and publication bias tests were performed.

RESULTS

Fifty-five eligible articles representing 109 611 Chinese new recruits met the inclusion criteria, of which 21 253 recruits were clinically diagnosed with military training-related injuries. The combined incidence of military training-related injuries in Chinese new recruits was found to be 21.04%.

CONCLUSIONS

An increased incidence of training injuries was found in more recent years, underscoring the need for further research on the risk factors associated with their causation.

Secular Trends in the Physical Fitness of United States Army Recruits on Entry to Service, 1975-2013

Knapik, JJ, Sharp, MA, and Steelman, RA. Secular trends in the physical fitness of United States Army recruits on entry to service, 1975-2013. J Strength Cond Res 31(7): 2030-2052, 2017-A systematic literature search was conducted to identify and analyze articles that reported on physical fitness of new US Army recruits. The National Library of Medicine's PubMed and the Defense Technical Information Center were searched using the keywords (military personnel OR trainee OR recruit OR soldier) AND (physical fitness OR strength OR endurance OR flexibility OR balance OR coordination OR muscle contraction OR running OR exercise OR physical conditioning). Reference lists of obtained articles and contact with authors enhanced the search. Studies were selected if they involved recruits in Basic Combat Training or One-Station Unit Training, provided a quantitative assessment of at least one fitness measure, and the fitness measure(s) were obtained early in training. Average values for each fitness measure were obtained, plotted by the year of data collection, and fitted to linear regression models (fitness measure × year). Fifty-three articles met the review criteria. Regression analysis indicated little temporal change in height, but body weight, body mass index, body fat, and fat-free mass increased over time. Limited V[Combining Dot Above]O2max data suggested no temporal change in male recruits, but those in female recruits V[Combining Dot Above]O2max seem to have slightly improved. Apparently contradicting the V[Combining Dot Above]O2max findings, performance on endurance runs (1- and 2-mile) declined, possibly because of the increase in body weight. Muscular endurance (push-ups, sit-ups) demonstrated little systematic change over time. Limited but multiple measures of muscular strength suggest a temporal increase in strength. Specific components of US Army recruit fitness seem to have changed over time.

Musculoskeletal injuries in British Army recruits: a prospective study of incidence in different Infantry Regiments

BACKGROUND

Musculoskeletal injuries and attrition incurred during basic military training are a significant socioeconomic burden across many Defence Forces. In order to plan an injury prevention strategy, the purpose of this study was to quantify the regiment-specific musculoskeletal injury patterns and training outcomes.

METHODS

This was a prospective observational study of the Parachute (n=734), Guards (n=1044), Line (n=3472) and Gurkha (n=458) Regiments of the British Army recruits during a 26-week basic military training programme over a 2-year period. The participant demographic characteristics were: age 18.9 years (SD±2.3), height 176.5 cm (SD±7.80), mass 69 kg (SD±9.7) and body mass index 22.14 kg/m² (SD±2.5).

RESULTS

The incidence of injuries (86%, 46%, 48% and 10%) was significantly different (p<0.001) as were the first time pass out rates (p=0.02) of 38%, 51%, 56% and 98% for Parachute, Guards, Line and Gurkha, respectively. Overuse injuries were more frequently reported than both acute and recurrent injuries in all regiments (X²=688.01, p<0.01).

CONCLUSIONS

The disparity in injury incidence and training outcome between Infantry Regiments suggests that the demands of training be taken into account when devising injury prevention strategies.

Development of a Prediction Model for Stress Fracture During an Intensive Physical Training Program: The Royal Marines Commandos

BACKGROUND

Stress fractures (SFs) are one of the more severe overuse injuries in military training, and therefore, knowledge of potential risk factors is needed to assist in developing mitigating strategies.

PURPOSE

To develop a prediction model for risk of SF in Royal Marines (RM) recruits during an arduous military training program.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

RM recruits (N = 1082; age range, 16-33 years) who enrolled between September 2009 and July 2010 were prospectively followed through the 32-week RM training program. SF diagnosis was confirmed from a positive radiograph or magnetic resonance imaging scan. Potential risk factors assessed at week 1 included recruit characteristics, anthropometric assessment, dietary supplement use, lifestyle habits, fitness assessment, blood samples, 25(OH)D, bone strength as measured by heel broadband ultrasound attention, history of physical activity, and previous and current food intake. A logistic least absolute shrinkage and selection operator (LASSO) regression with 10-fold cross-validation was used to select potential predictors among 47 candidate variables. Model performance was assessed using measures of discrimination (c-index) and calibration. Bootstrapping was used for internal validation of the developed model and to quantify optimism.

RESULTS

A total of 86 (8%) volunteer recruits presented at least 1 SF during training. Twelve variables were identified as the most important risk factors of SF. Variables strongly associated with SF were age, body weight, pretraining weightbearing exercise, pretraining cycling, and childhood intake of milk and milk products. The c-index for the prediction model, which represents the model performance in future volunteers, was 0.73 (optimism-corrected c-index, 0.68). Although 25(OH)D and VO₂max had only a borderline statistically significant association with SF, the inclusion of these factors improved the performance of the model.

CONCLUSION

These findings will assist in identifying recruits at greater risk of SF during training and will support interventions to mitigate this injury risk. However, external validation of the model is still required.

APTIDÃO FÍSICA E LESÕES: 54 SEMANAS DE TREINAMENTO FÍSICO COM POLICIAIS MILITARES

RESUMO Introdução: A aptidão física é imprescindível para policiais militares. Entretanto, apesar de a finalidade do treinamento militar ser o aperfeiçoamento de diferentes componentes da aptidão física, sua execução de forma não adequada pode associar-se ao desenvolvimento de lesões musculoesqueléticas. Objetivo: Verificar o efeito do treinamento físico militar sobre indicadores de aptidão física e incidência de lesões musculoesqueléticas em participantes do Curso de Formação de Soldados da Polícia Militar do Estado de São Paulo. Método: A amostra foi composta por 86 homens que foram submetidos ao Teste de Aptidão Física no início e depois de 54 semanas de treinamento. As informações sobre lesões foram obtidas com questionário específico. Resultados: Houve melhora significativa do volume máximo de oxigênio (VO2máx), resistência muscular localizada, força e velocidade ao final do treinamento. Entretanto, 45,3% dos policiais sofreram uma ou mais lesões, sendo 65,6% delas concentradas nos membros inferiores, 18% nos membros superiores e 16,4% no tronco e na cabeça. O nível osteoarticular concentrou 50,8% das lesões, o nível músculo-ligamentar, 26,3% e o tegumentar, 22,9%. Conclusão: Apesar do resultado satisfatório em relação à aptidão física, a incidência de lesões entre os policiais foi elevada.

Association of Pain With Physical Function, Depressive Symptoms, Fatigue, and Sleep Quality Among Veteran and non-Veteran Postmenopausal Women

PURPOSE OF STUDY

To characterize the prevalence and longitudinal effects of pain in older Veteran and non-Veteran women.

DESIGN AND METHODS

Data on 144,956 participants in the Women's Health Initiative were analyzed. At baseline, Veteran status, pain severity, and pain interference with activity were assessed. Outcomes of physical function, depressive symptoms, fatigue, and sleep quality were reported at baseline by all study participants and longitudinally on two follow-up occasions (3 years and 13-18 years after baseline) in the observational study participants (n = 87,336).

RESULTS

At baseline, a total of 3,687 (2.5%) had a history of military service and 22,813 (15.8%) reported that pain limited their activity level moderately to extremely during the past 4 weeks. Prevalence of pain interference did not differ in Veterans and non-Veterans (16.8% and 15.7%, respectively; p= .09). At baseline, women with moderate-to-extreme pain interference had substantially worse physical function and greater symptoms of depression, fatigue, and insomnia than those with less pain (p < .001 for all comparisons), adjusting for several social, behavioral, and health related factors. There were no significant military service by pain interference interactions for any of the outcomes (p > .2), indicating that the effect of pain interference on outcomes at baseline did not vary between Veterans and non-Veterans. Moderate-to-extreme pain interference was associated with a greater rate of decline in physical function over time (p < .001) and higher incidence of limited physical functioning (p < .001), but these effects did not vary by Veteran status. Similar results were observed with pain severity as the exposure variable.

IMPLICATIONS

As the Veteran population ages and the number of women exposed to combat operations grows, there will be an increased need for health care services that address not only pain severity and interference but also other disabling comorbid symptoms.

Description and Rate of Musculoskeletal Injuries in Air Force Basic Military Trainees, 2012-2014

CONTEXT

 Musculoskeletal injuries are common in military trainees and have significant medical and operational effects.

OBJECTIVE

 To provide current musculoskeletal injury epidemiology data for US Air Force basic military trainees.

DESIGN

 Descriptive epidemiologic study with cross-sectional features.

SETTING

 US Air Force Basic Military Training, Joint Base San Antonio-Lackland, Texas.

PATIENTS OR OTHER PARTICIPANTS

 All recruits who entered training between July 1, 2012, and June 30, 2014.

MAIN OUTCOME MEASURE(S)

 Incidence density rate of all musculoskeletal injuries (stratified by body region and type) and factors and costs associated with injuries.

RESULTS

 Of the 67 525 trainees, 12.5% sustained 1 or more musculoskeletal injuries. The overall incidence density rate was 18.3 injuries per 1000 person-weeks (15.1 for men and 29.4 for women). The most common diagnosis (n = 2984) was Pain in joint, lower leg, as described in the International Classification of Diseases, Ninth Revision, Clinical Modification, code 719.46. Injuries were more common among those with lower levels of baseline aerobic and muscular fitness. Injured trainees were 3.01 times (95% confidence interval = 2.85, 3.18) as likely to be discharged, and injured trainees who did graduate were 2.88 times (95% confidence interval = 2.72, 3.04) as likely to graduate late. During the surveillance period, injuries resulted in more than $43.7 million in medical ($8.7 million) and nonmedical ($35 million) costs.

CONCLUSIONS

 Musculoskeletal injuries, predominantly of the lower extremities, have significant fiscal and operational effects on Air Force Basic Military Training. Further research into prevention and early rehabilitation of these injuries in military trainees is warranted.

Risk factors for back pain in marines; a prospective cohort study

Background

It is recognised that back pain (BP) is a debilitating medical problem in the soldier community, which limits operational readiness as well as work ability. As such, identification of risk factors is a necessity for effective preventive actions, but also regarded as important from a safety perspective. The aim of this prospective cohort study was therefore to identify risk factors for back pain and BP limiting work ability in active duty marines within a 6 and 12-month period.

Methods

Demographic characteristics, health-related factors and occupational exposure information, as gathered from questionnaires, as well as clinical test of movement control among 137 Swedish marines were regressed with multivariable logistic regressions, and strength of associations was presented as odds ratio (OR) with 95 % confidence intervals (CI). BP within 6 and 12 months were used as primary outcomes, whereas BP limiting work ability within 6 and 12 months served as secondary outcomes.

Results

Previous BP and tall body height (≥1.86 m) emerged as risk factors for back pain within 6 months (OR 2.99, 95 % CI 1.22–7.30; OR 2.81, 95 % CI 1.16– 6.84, respectively), and 12 months (OR 6.75, 95 % CI 2.30–19.80; 2.75, 95 % CI 1.21–6.29, respectively). Previous BP was also identified as risk factor for BP limiting work ability within 12 months (OR 6.64, 95 % CI 1.78–24.78), and tall body height emerged as a risk within both six (OR 4.30, 95 % CI 1.31–14.13) and 12 months (OR 4.55, 95 % CI 1.53–13.57) from baseline.

Conclusions

Marines with a history of BP are at risk of further BP episodes, which, thus, emphasise the importance of early BP preventive actions. Tall body height also emerged as an important risk which may reflect that personal equipment and work tasks are not adapted for the tallest marines. While this should be considered when introducing new work equipment, further studies are warranted to clarify the underlying mechanism of this association.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1172-y) contains supplementary material, which is available to authorized users.

BMI and Lower Extremity Injury in U.S. Army Soldiers, 2001-2011

INTRODUCTION

Little data exist regarding the long-term impact of excess weight on lower extremity musculoskeletal injury/disorder (MID) in U.S. Army Soldiers. This prospective analysis examines the association between BMI of Soldiers at accession and risk of MID.

METHODS

A total of 736,608 Soldiers were followed from accession into the Army, 2001-2011. Data were analyzed January through March 2015. MID was categorized as any first incident lower extremity musculoskeletal injury/disorder, and secondarily, as first incident injury/disorder at a specific site (i.e., hips, upper legs/thighs, knees, lower legs/ankles, feet/toes). Multivariable-adjusted proportional hazards models estimated associations between BMI category at accession and MID risk.

RESULTS

During 15,678,743 person-months of follow-up, 411,413 cases of any first MID were documented (70,578 hip, 77,050 upper leg, 162,041 knee, 338,080 lower leg, and 100,935 foot injuries in secondary analyses). The overall MID rate was 2.62 per 100 person-months. Relative to Soldiers with normal BMI (18.5 to <25 kg/m(2)) at accession, those who were underweight (<18.5); overweight (25 to <30); or obese (≥30) had 7%, 11%, and 33% higher risk of MID, respectively, after adjustment. Risks were highest in Soldiers who were obese at accession, and lowest in those with a BMI of 21-23 kg/m(2).

CONCLUSIONS

Soldier BMI at accession has important implications for MID. A BMI of 21-23 kg/m(2) in newly accessing Soldiers was associated with the lowest risk of incident MID, suggesting that accession be limited to people within this range to reduce overall incidence of MID among service personnel.

Low fitness, low body mass and prior injury predict injury risk during military recruit training: a prospective cohort study in the British Army

Background

Injuries sustained by military recruits during initial training impede training progression and military readiness while increasing financial costs. This study investigated training-related injuries and injury risk factors among British Army infantry recruits.

Methods

Recruits starting infantry training at the British Army Infantry Training Centre between September 2008 and March 2010 were eligible to take part. Information regarding lifestyle behaviours and injury history was collected using the Military Pre-training Questionnaire. Sociodemographic, anthropometric, physical fitness and injury (lower limb and lower back) data were obtained from Army databases. Univariable and multivariable Cox regression models were used to explore the association between time to first training injury and potential risk factors.

Results

58% (95% CI 55% to 60%) of 1810 recruits sustained at least 1 injury during training. Overuse injuries were more common than traumatic injuries (65% and 35%, respectively). The lower leg accounted for 81% of all injuries, and non-specific soft tissue damage was the leading diagnosis (55% of all injuries). Injuries resulted in 122 (118 to 126) training days lost per 1000 person-days. Slower 2.4 km run time, low body mass, past injury and shin pain were independently associated with higher risk of any injury.

Conclusions

There was a high incidence of overuse injuries in British Army recruits undertaking infantry training. Recruits with lower pretraining fitness levels, low body mass and past injuries were at higher risk. Faster 2.4 km run time performance and minimal body mass standards should be considered for physical entry criteria.

Association between pain catastrophising and musculoskeletal disorders is modified by past injuries in Malaysian military recruits

OBJECTIVES

Pain catastrophising is defined as exaggerated negative thoughts, which can occur during an actual or anticipated painful experience, such as musculoskeletal injuries (MSI) or disorders (MSD). The aims of this study are to examine the association between pain catastrophising and MSI and MSD in Malaysian Army male recruits, and evaluate the effects of past injury.

METHODS

A cohort of 611 male Malaysian Army recruits were recruited and followed up at 3 and 6 months. Pain catastrophising, MSD, sociodemographic and work factors were measured using a self-administered questionnaire, and MSI incidence was retrieved from the medical records. Multivariable fixed effects regression was used to model the cumulative incidence of MSD and MSI.

RESULTS

Approximately 12% of the recruits were diagnosed with incident MSI and 80% reported incident MSD. Higher pain catastrophising at baseline was associated with higher 6 month MSD risk (adjusted OR (aOR) 1.6 per 1 SD increase of Pain Catastrophising Scale (PCS) scores; 95% CI 1.2 to 2.0), and longitudinally associated with MSD incidence (aOR 1.2, 95% CI 1.1 to 1.4). Pain catastrophising was not associated with MSI incidence (aOR 1.0, 95% CI 0.8 to 1.3). The association between pain catastrophising and self-reported MSD was stronger among recruits with self-reported past injury (p for interaction <0.001).

CONCLUSIONS

Pain catastrophising was able to predict symptomatic MSD, and not physician-diagnosed MSI, and these findings are directly related to individual health beliefs. Pain catastrophising has a greater influence on how military recruits perceived their musculoskeletal conditions during training, and efforts to reduce pain catastrophising may be beneficial.

Efficacy of functional movement screening for predicting injuries in coast guard cadets

Functional movement screening (FMS) examines the ability of individuals to perform highly specific movements with the aim of identifying individuals who have functional limitations or asymmetries. It is assumed that individuals who can more effectively accomplish the required movements have a lower injury risk. This study determined the ability of FMS to predict injuries in the United States Coast Guard (USCG) cadets. Seven hundred seventy male and 275 female USCG freshman cadets were administered the 7 FMS tests before the physically intense 8-week Summer Warfare Annual Basic (SWAB) training. Physical training-related injuries were recorded during SWAB training. Cumulative injury incidence was calculated at various FMS cutpoint scores. The ability of the FMS total score to predict injuries was examined by calculating sensitivity and specificity. Determination of the FMS cutpoint that maximized specificity and sensitivity was determined from the Youden's index (sensitivity + specificity - 1). For men, FMS scores ≤ 12 were associated with higher injury risk than scores >12; for women, FMS scores ≤ 15 were associated with higher injury risk than scores >15. The Youden's Index indicated that the optimal FMS cutpoint was ≤ 11 for men (22% sensitivity, 87% specificity) and ≤ 14 for women (60% sensitivity, 61% specificity). Functional movement screening demonstrated moderate prognostic accuracy for determining injury risk among female Coast Guard cadets but relatively low accuracy among male cadets. Attempting to predict injury risk based on the FMS test seems to have some limited promise based on the present and past investigations.

Musculoskeletal pain and limitations in work ability in Swedish marines: a cross-sectional survey of prevalence and associated factors

OBJECTIVES

To estimate the prevalence of self-rated musculoskeletal pain and pain limiting work ability in Swedish Armed Forces (SAF) marines, and to study factors potentially associated with pain limiting work ability for the most prevalent pain regions reported.

DESIGN

Population-based, cross-sectional survey.

PARTICIPANTS

There were 272 SAF marines from the main marine battalion in Sweden included in the study.

OUTCOMES

Self-assessed musculoskeletal pain and pain limiting the marines' work ability within a 6-month period, as obtained from structured questionnaires. The association of individual, health and work-related factors with musculoskeletal pain limiting work ability was systematically regressed with multiple logistic models, estimating OR and 95% CI.

RESULTS

Musculoskeletal pain and pain limiting work ability were most common in the back, at 46% and 20%, and lower extremities at 51% and 29%, respectively. Physical training ≤1 day/week (OR 5.3, 95% CI 1.7 to 16.8); body height ≤1.80 m (OR 5.0, 95% CI 1.6 to 15.1) and ≥1.86 m (OR 4.4, 95% CI 1.4 to 14.1); computer work 1/4 of the working day (OR 3.2, 95% CI 1.0 to 10.0) and ≥1/2 (OR 3.3, 95% CI 1.1 to 10.1) of the working day were independently associated with back pain limiting work ability. None of the studied variables emerged significantly associated with such pain for the lower extremities.

CONCLUSIONS

Our findings show that musculoskeletal pain and resultant limitations in work ability are common in SAF marines. Low frequency of physical training emerged independently associated with back pain limiting work ability. This suggests that marines performing physical training 1 day per week or less are suitable candidates for further medical evaluation and secondary preventive actions. While also associated, body height and computer work need further exploration as underlying mechanisms for back pain limiting work ability. Further prospective studies are necessary to clarify the direction of causality.

Musculoskeletal injuries in British Army recruits: a prospective study of diagnosis-specific incidence and rehabilitation times

Background

Musculoskeletal injuries during initial military training are a significant medical problem facing military organisations globally. In order to develop an injury management programme, this study aims to quantify the incidence and rehabilitation times for injury specific diagnoses.

Methods

This was a prospective follow-up study of musculoskeletal injuries in 6608 British Army recruits during a 26-week initial military training programme over a 2-year period. Incidence and rehabilitation times for injury specific diagnoses were recorded and analysed.

Results

During the study period the overall incidence of musculoskeletal injuries was 48.6%, and the most common diagnosis was iliotibial band syndrome (6.2%). A significant proportion of the injuries occurred during the first 11 weeks of the programme. The longest rehabilitation times were for stress fractures of the femur, calcaneus and tibia (116 ± 17 days, 92 ± 12 days, and 85 ± 11 days, respectively). The combination of high incidence and lengthy rehabilitation indicates that medial tibial stress syndrome had the greatest impact on training, accounting for almost 20% of all days spent in rehabilitation.

Conclusion

When setting prevention priorities consideration should be given to both the incidence of specific injury diagnoses and their associated time to recovery.

Injury during U.S. Army basic combat training: a systematic review of risk factor studies

CONTEXT

Approximately one quarter of men and half of women in U.S. Army basic combat training experience an injury. Preventing basic combat training-related injuries would reduce associated human and economic costs and discharges from the Army. Identification of risk factors for such injuries is a crucial step toward their prevention. Although some research has begun to address this need, prior studies of risk factors for training-related injury have not been reviewed systematically. This study systematically reviews the literature on risk factors for injury during U.S. Army basic combat training.

EVIDENCE ACQUISITION

Original studies of risk factors for injury during U.S. Army basic combat training published since 1990 in peer-reviewed journals were identified using PubMed and manual searches of reference lists. This search was last performed in May 2013. Nineteen studies met the inclusion criteria.

EVIDENCE SYNTHESIS

Methodologic quality and potential for bias were assessed. The findings of 11 studies deemed to be of high or medium quality were synthesized to determine the level of evidence supporting the association between each risk factor studied and risk of injury during basic combat training. Quality assessment and evidence synthesis were performed from June to September 2013.

CONCLUSIONS

There is strong or moderate evidence supporting association of older age, history of smoking, and self-rated low physical activity level prior to basic combat training with increased risk of training-related injury among male trainees. There is limited, mixed, or insufficient evidence to identify risk factors for injury among female trainees.