Risk factors of acute and overuse musculoskeletal injuries among young conscripts: a population-based cohort study

Does policy that provides choice in athletic footwear affect musculoskeletal injury risk in US Coast Guard recruits?

INTRODUCTION

Musculoskeletal injuries (MSKIs) are ubiquitous during initial entry military training, with overuse injuries the most common. A common injury mechanism is running, an activity that is integral to US Coast Guard (USCG) training and a requirement for graduation. The purpose of this study was to assess the effects of a policy that allowed for athletic footwear choice on risk of lower quarter MSKI in USCG recruits.

METHODS

A retrospective cohort study was performed that included 1230 recruits (1040 men, 190 women) who trained under a policy that allowed self-selection of athletic footwear and 2951 recruits (2329 men, 622 women) who trained under a policy that mandated use of prescribed uniform athletic shoes and served as controls. Demographic data and physical performance were derived from administrative records. Injury data were abstracted from a medical tracking database. Unadjusted risk calculations and multivariable logistic regression assessing the effects of group, age, sex, height, body mass and 2.4 km run times on MSKI were performed.

RESULTS

Ankle-foot, leg, knee and lumbopelvic-hip complex injuries were ubiquitous in both groups (experimental: 13.13 per 1000 person-weeks; control: 11.69 per 1000 person-weeks). Group was not a significant factor for any of the injuries assessed in either the unadjusted or adjusted analysis, despite widespread reports of pain (58.6%), perceived injury attribution (15.7%), perceived deleterious effect on performance (25.3%), general dissatisfaction (46.3%) and intended discontinuance of use following graduation (87.7%).

CONCLUSION

MSKI continues to be a major source of morbidity in the recruit training population. The policy that allowed USCG recruits to self-select athletic footwear did not decrease or increase the risk of MSKI. While regulations pertaining to footwear choice did not influence injury outcomes, there was general dissatisfaction with the prescribed uniform athletic footwear conveyed by the recruits and widespread reports of discomfort, perceived deleterious effects from wear and intended discontinued use following training completion.

Risk Factors Associated with Musculoskeletal Injuries within the Crew of the Leopard 2 A6 Main Battle Tank Using Inertial Movement Unit Sensors: A Pilot Study

This study aims to assess the musculoskeletal risk of military personnel on a Leopard 2 A6 main battle tank crew and to identify associated factors for future prevention and mitigation strategies. A sample of 57 Portuguese military personnel, who are or were part of the Leopard 2 A6 main battle tank crew, answered a questionnaire on their perception of task performance, considering muscle demands, comfort, posture, movements, and associated symptoms. A subsample of four soldiers from the Armoured Squadron of the Portuguese Mechanized Brigade were assessed using an inertial measurement unit system and underwent a whole-body kinematic analysis coupled with a Rapid Entire Body Assessment during a simulated two-hour mission. The results indicate that soldiers accurately perceive their roles within the crew and that, overall, there is a high risk of musculoskeletal injuries in all tasks. However, tasks directly related to the crew's primary duties carry consistently high risk when considering the time spent on their tasks. This study highlights the need for targeted preventive measures to reduce the incidence and severity of injuries among the crew of the Leopard 2 A6 main battle tank.

The Value of Strength as a Predictor of Musculoskeletal Injury in Canadian Armed Forces Basic Infantry Candidates

INTRODUCTION

Musculoskeletal injuries (MSKI) impact military organizations by threatening their operational readiness, warranting investigation into relevant factors to inform risk reduction strategies. While several self-reported and physical performance measures have been associated with MSKI among military personnel, few have been validated and none have been reported in Canadian basic infantry candidates. The purpose of this study was to investigate associations between self-reported and physical performance measures and MSKI, and determine their validity as predictors of MSKI, in Canadian basic infantry candidates.

METHODS

This was a planned secondary analysis of a study tracking MSKI at a basic infantry training facility in Ontario, Canada approved by Defence Research & Development Canada. Before the basic infantry training, consenting candidates completed a baseline testing session including self-reported questionnaires, measures of anthropometry, and physical performance previously associated with MSKI (ankle dorsiflexion test, Y-Balance Test, Isometric Mid-Thigh Pull, and the Fitness for Operational Requirements of CAF Employment (FORCE) evaluation). All MSKI reported by candidates were diagnosed by licensed healthcare providers. From a total sample of 129 candidates, 76% (n = 98) were used to determine any associations between baseline testing variables and MSKI and to develop a predictive model (Development Sample), while 24% (n = 33) were used to offer preliminary validation of the same predictive model (Validation Sample). The binary logistic regression and independent sample t-testing determined independent associations with MSKI in the Development Sample. All continuous variables and dichotomous variables previously associated with MSKI risk (Smoker Yes/No, previous history of MSKI, and physical inactivity) were entered into a backward stepwise logistic regression analysis to assess the predictive association with MSKI incidence in the Development Sample. The regression model was then applied to the Validation Sample.

RESULTS

A total of 35 MSKI were diagnosed by Health Services Centre staff. The majority of the MSKI were acute (63%), sustained to the hip, knee, and ankle (74%). The most common diagnoses were strains and sprains (71%). Uninjured participants performed significantly better on the Relative Isometric Mid-Thigh Pull, FORCE 20 mR, FORCE ILS, and FORCE Estimated VO2peak compared to injured participants. Logistic regression analysis showed that the only variable with significant independent association with diagnosed MSKI incidence was self-reported previous history of MSKI. However, the backward stepwise logistic regression analysis retained self-reported previous history of MSKI, FORCE SBD, FORCE Estimated VO2peak, and Isometric Mid-Thigh Pull Peak Force as predictors of MKSI. The logistic regression model including these variables could predict MSKI with an accuracy of 79% in the Development Sample and 67% in the Validation Sample.

CONCLUSION

This study provides preliminary support for the value of measures of absolute muscular strength and cardiorespiratory fitness as predictors of MSKI in Canadian basic infantry candidates. Given the associations between physical performance measures and MSKI, and their necessity during occupational tasks, it is recommended that Canadian basic infantry training facilities integrate resistance training with external loads to best prepare their candidates to meet their occupational demands and potentially minimize MSKI. Further investigations to confirm the predictive capacity of these variables in a larger sample across additional facilities are warranted.

Femoral anteversion linked to the inability to squat: Analysis of CT images in the patient and control groups

Many patients who cannot squat well in a neutral toe position can only squat in an excessively out-toeing position. This excessive out-toeing squat is thought to be caused by rotational problems of the lower extremities. In this study, we aimed to identify the cause for the inability to squat by measuring and comparing femoral and tibial torsion between an excessive out-toeing squat patient group and a control group representing the general population. Between 2008 and 2022, a patient group comprising 50 lower extremities with excessive out-toeing squats was established. A control group representing the general population was selected from patients aged 0 to 29 years, who underwent lower-extremity CT angiography between 2012 and 2022, using the Clinical Data Warehouse with exclusion criteria applied. A total of 94 lower extremities were included in the control group. The femoral torsional angle (FTA) and tibial torsional angle (TTA) of both groups were measured and compared using Student t test. Additionally, 30 each of those with the highest and lowest 30 FTA values were selected from the patient and control groups, and the TTA was compared between the high- and low-FTA groups using Student t test. The mean FTA was 0.34° (SD, 11.11°) in the patient group and 10.14° (SD, 11.85°) in the control group, with a mean difference of 9.8° and P < .001. The mean TTA was 27.95° (SD, 7.82°) in the patient group and 32.67 ° (SD, 7.58°) in the control group, with a mean difference of 4.72° (P = .001). The mean TTA was 34.3° (SD, 7.72°) in the high-FTA group and 28.17° (SD, 8.35°) in the low-FTA group, with a mean difference of 6.13° (P = .005). Patients with excessive out-toeing squat showed lower FTA and TTA values than the general population. Furthermore, although a correlation between FTA and TTA was not established through Pearson correlation analysis, a tendency was observed where a decrease in FTA was associated with a decrease in TTA. Based on these results, decreased FTA was demonstrated to be one of the major causes of excessive out-toeing squats.

A Functional Drink Containing Kaempferia parviflora Extract Increases Cardiorespiratory Fitness and Physical Flexibility in Adult Volunteers

Owing to the reputation of Kaempferia parviflora and the crucial role of oxidative stress on the disturbance of physical fitness, the effect of a functional drink containing K. parviflora extract (KP) on the physical fitness of healthy adult volunteers was assessed. Healthy male and female volunteers (19-60 years old) were randomly divided into placebo, KP90, and KP180 groups. All the subjects in KP90 and KP180 were directed to consume a functional drink containing K. parviflora extract at doses of 90 and 180 mg per serving per 80 mL, respectively. Parameters of physical fitness, including cardiovascular endurance, muscular strength and endurance, flexibility, and body composition, together with changes in lactate, creatinine kinase, and oxidative stress markers were assessed before the intervention, and at 6 and 12 weeks of intervention. The oxidative stress markers, creatine kinase, and lactate were also measured. Subjects who consumed the developed drink had increased VO2 max and improved performance in a timed shuttle run test and 5 min distance run, and exhibited decreased oxidative stress and lactate; therefore, K. parviflora extract can be successfully used for developing a KP drink to improve cardiorespiratory fitness and physical performance by improving oxidative stress and lactate.

Achilles Tendon and Patellar Tendon Structure in Combat Soldiers Following Prevention Exercises

INTRODUCTION

Military training that increases physical stress on musculoskeletal morphology also increases the risk of orthopedic injuries. Somatosensory prevention programs that reduce stress and improve functionality could be beneficial for better organization of tendon structure. The aim of this study was to investigate the impact of a somatosensory prevention exercise on the tendon structure (percentage of echo-type fibers; A-P and M-L diameters and cross-sectional area) of the Achilles tendon and patellar tendon among combat soldiers.

MATERIALS AND METHODS

These tendons of male Infantry soldiers aged 18-21 were screened before and after a 14-week training course. The intervention group, who performed preventative exercises, included 108 soldiers (BMI = 23.85 ± 2.76), while the control group, who participated in the same military course without these exercises, included 98 soldiers (BMI = 24.26 ± 4.03). Ultrasound scanning for tendon structure included percent of echo-type I-IV fibers, A-P diameter, M-L diameter, and cross-sectional area parameters.

RESULTS

Time by group interaction was found for echo-type I and II in both tendons. No significant differences were found between the two groups in the pretesting percentage of echo-type IV fibers of the Achilles tendon (P = .522), in echo-type III fibers of the Achilles tendon (P = .833), and echo-type IV fibers of the patellar tendon (P = .162). Greater pre-post differences in echo-type III and IV fibers were found in the control group compared with the intervention group for both the Achilles tendon (P = .021, P = .002) and the patellar tendon (P < .001, P < .001).

CONCLUSION

Increased damaged fibers (echo-type III and IV) of both tendons were found among the control group, yet not among soldiers who performed prevention exercises.

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.

Achilles and patellar tendon structure following a prevention program in male combat soldiers

OBJECTIVES

The aims of the study were to compare the prevalence of soldiers with musculoskeletal symptoms between soldiers that participated in a prevention program (INT) and a control group (CONT); and, to assess whether 'high risk' for a symptom indicator [participants with patellar tendon (PT) echo-type III+IV >10% or Achilles tendon (AT) echo-type III >8.5%] applies when a prevention intervention is used.

METHODS

Soldiers from two consecutive infantry commanders courses (year 1-CONT, n = 165; year 2-INT, n = 196) were examined pre-course for AT and PT structure using ultrasound tissue characterization (UTC), and their musculoskeletal overuse symptoms were assessed and recorded by military physicians throughout the course. A prevention program was provided to the INT group (year 2) during the 14-week course.

RESULTS

No significant differences were found in the prevalence of soldiers with symptoms between the two groups [INT: 39 (19.9%), CONT: 40 (24.2%); p = .32]. Using the indicator at baseline, 20 soldiers (10.2%) were suggested to be at 'high risk.' Of those 20 soldiers, 17 actually had symptoms during the course (positive predictive value-85%). The prevalence of soldiers with a suggested 'high risk' according to our indicator who had no symptoms during the course was low (3/20, 15%). Twenty-two soldiers who had symptoms during the course had not been suggested to be at 'high risk' by our indicator.

CONCLUSION

Our intervention did not reduce the prevalence of soldiers with symptoms. Our 'high risk' pre-course, AT and PT structure indicator is valid and can be used as a screening tool to reduce the prevalence of symptoms in combat soldiers; with the caution that soldiers that were not identified by the indicator, might also have symptoms along the course.

Effects of prevention programmes on injury risk in military personnel: a systematic review with meta-analysis

INTRODUCTION

Exercise programmes have been used to prevent injuries in military personnel, as they can reduce modifiable risk factors for injuries. Our aim was to review the literature to evaluate the effects of different exercise protocols on the prevention of injuries in military personnel.

METHODS

A systematic literature review examined the effects of different exercise protocols on the prevention of musculoskeletal injuries in the military. Several databases were explored to find experimental studies that investigated the effects of prevention programmes on the risk of injury. We have extracted from the studies: profile of participants, sample size, study design and characteristics of the control group (CG), the type of intervention and the relative risk (RR) in the experimental group and CG, with their significance levels. For data analysis, we used the RevMan V.5.3 software. The measure of RR was investigated. The risk of publication bias was analysed with Begg's test.

RESULTS

A total of 13 694 titles and studies were recovered from the databases and by manual search. After the removal of duplicate titles and studies that did not meet the eligibility criteria, 17 studies were selected. The protocols were composed of neuromuscular training, stretching, agility training or combined exercises. The meta-analysis showed that injury prevention exercise programmes reduced the risk of musculoskeletal injuries in military personnel by 14% (RR=0.86; 95% CI=0.76 to 0.98).

CONCLUSION

Injury prevention exercise programmes promoted a slight reduction in the risk of musculoskeletal injuries in military personnel.

LEVEL OF EVIDENCE

Very low.

TRIAL REGISTRATION NUMBER

CRD 42017077946.

The performance of body mass component indices in detecting risk of musculoskeletal injuries in physically active young men and women

BACKGROUND

Body composition indices can be related to musculoskeletal injuries (MI), particularly in physically active groups. However, little is known about the accuracy of these diagnoses as potential predictors of musculoskeletal injuries. Therefore, this study aims to indicate the cut-off points of relative body mass (BMI), fat mass index (FMI), skeletal muscle mass (SMI), and muscle to fat ratio (MFR) and establish its reliability in injury prediction for physically active men and women.

METHODS

The sample included 119 physically active individuals aged 23.72 ± 1.12 (66 men body height 1.79 ± 0.07 (m); body weight 80.51 ± 9.85 (kg) and 53 women body height 1.67 ± 0.08 (m); body weight 62 ± 10.72 (kg)), students at university of physical education in Poland. The participants' physical activity was measured with the International Physical Activity Questionnaire (IPAQ). The relevance of body mass index (BMI), fat mass index (FMI), skeletal muscle mass index (SMI), and muscle to fat ratio (MFR) in detecting injury risk was examined. Musculoskeletal injuries during 1 year before examination were registered using a self-reporting questionnaire. The areas under the curve (AUC) and Youden Index in the receiver operating characteristic curve (ROC) were calculated.

RESULTS

The cut-off points used to classify the indices among men were BMI = 24.38; FMI = 3.74; SMI = 16.40; MFR = 3.70; and for women BMI = 20.90; FMI = 4.17; SMI = 8.96; MFR = 1.67. Results suggested the greatest reliability in the prediction of musculoskeletal injuries among men had BMI (AUC = 0.623; Youden = 0.30) and SMI (AUC = 0.608; Youden = 0.23) whereas among women, MFR (AUC = 0.628; Youden = 0.29) and FMI (AUC = 0.614; Youden = 0.32).

CONCLUSION

BMI and SMI are the most appropriate indices to predict the risk of musculoskeletal injury in physically active men, whereas in women, MFR and FMI are more reliable. These results indicate that the indices with more muscle mass meaning are better in predicting injury among men. In contrast, indices with a higher contribution of fat are better for women. It indicates sex differentiation of injury risk conditions. Men should focus on developing muscle mass, whereas women should reduce body fat to decrease injury risk. However, widespread use seemed to be limited to the specific examined group. Therefore, cut-off points should be used with caution, and calculated values should be verified and confirmed in subsequent studies.

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.

Relationship of footwear comfort, selected size, and lower leg overuse injuries among infantry soldiers

BACKGROUND

High rates of musculoskeletal injuries such as plantar fasciitis and stress fractures have been observed among physically active military personnel. During service time, infantry soldiers use issued boots daily that should fit well and provide comfort to prevent injuries and decrease lower extremity pain effectively. The association of military boot comfort with overuse injuries remains unclear. This study investigates the relationship between the chosen military boot size, perceived boot comfort and lower leg overuse injury.

METHODS

During the cross-sectional study, 227 (males, n = 213; females, n = 14) active-duty infantry soldiers at a mean age of 29.5 years old, and with an average service time of 7.2 years were assessed for a history of overuse injury, footprint length, appropriate shoe size, and footwear comfort. Males with a history of overuse injury (n = 32) and non-injured age-matched controls (n = 34) were selected for detailed testing and establishing the possible relationship between footwear comfort and lower leg overuse injury.

RESULTS

No relationship was found between footwear comfort and a history of lower leg overuse injury. N = 38 (57.6%) of study subjects were wearing an inappropriate shoe size daily. Inappropriate shoe size usage affected footwear comfort ratings significantly.

CONCLUSIONS

Study results showed that improper boot size was significantly related to comfort ratings but was not associated with a history of lower leg overuse injury.

COVID-19 and Youth Sports: What Are the Risks of Getting Back on the Field Too Quickly?

The widespread shutdown in response to the coronavirus disease 2019 (COVID-19) pandemic, although varied across state and county levels, has undoubtedly impacted everyone to some degree. Within the pediatric population, the closure of schools and organized youth athletic programs has resulted in a unique situation that has made athletes physically deconditioned and at risk for injury. As sports and competition gradually restart, there are considerable risks to the skeletally immature athlete. The anatomic and physiologic changes that occur to bone and cartilage during growth make the young athlete particularly susceptible to both acute and overuse injuries. In the context of the pandemic, deconditioning, obesity, lack of variety, and the resultant mental health burden pose unique challenges in ensuring that young athletes safely return to the field. This review aims to identify risk factors for sport-related injuries and to outline strategies for minimizing these injuries as pediatric patients return-to-play after COVID-19. [Pediatr Ann. 2021;50(11):e465-e469.].

Association between movement patterns and risk of musculoskeletal injuries in navy cadets: A cohort study

OBJECTIVE

To investigate the association of movement patterns evaluated by the Dynamic Movement Assessment (DMA) with the occurrence of musculoskeletal injuries in navy cadets.

DESIGN

Cohort study.

SETTING

Participants were filmed performing the six functional tests of the DMA (deep squat, step up, single-leg squat, hop, plank and side-plank tests).

PARTICIPANTS

240 navy cadets.

MAIN OUTCOME MEASUREMENTS

Depending on the number of certain movement patterns on the Dynamic Movement Assessment (DMA), participants were classified as high, moderate, medium or low risk of developing injuries. Predictive associations between injuries and risk classification were examined using logistic regression analysis.

RESULTS

Considering sex, previous injuries and the type of secondary school as covariates, participants who were classified as high risk were not more likely to develop injuries. Non-military high school was an independent risk factor for any injuries (OR = 3.14, 95% CI [1.43,6.91]; OR = 4.57, 95% CI [1.92,10.83]), overuse injuries (OR = 2.58, 95% CI [1.05,6.30]; OR = 2.55, 95% CI [1.06, 6.14]) and acute injuries (OR = 4.88, 95% CI [1.19,19.99]), respectively. Previous musculoskeletal symptoms also increased the chance of AI (OR = 4.45, 95% CI [1.15,17.18]; OR = 5.91, 95% CI [1.13,30.88]).

CONCLUSIONS

Movement patterns evaluated by DMA are not associated with an increased risk of injuries. However, attendance of a non-military high school and previous musculoskeletal symptoms are associated with musculoskeletal injuries.

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.

The Occupational Military Neuromusculoskeletal Injury Matrix

INTRODUCTION

Neuromusculoskeletal injuries (NMSKIs) are the primary cause of ambulatory visits, lost duty days, and disability discharges in the U.S. Military. Methods for accurately grouping injury diagnoses are required to allow for surveillance and research identifying risk factors and prevention strategies. The CDC method of grouping these diagnoses includes only the S and T codes (Injury, poisoning, and certain other consequences of external causes) from the ICD-10-CM. However, this does not include the majority of the NMSKI depleting soldier readiness; the M (Disease of the musculoskeletal system and connective tissue) and G (Diseases of the nervous system) codes should be included as these also contain injuries. The goal was to develop a new matrix that would comprehensively capture all NMSKIs experienced by military personnel. This paper details the development of the Occupational Military Neuromusculoskeletal Injury (OMNI) Matrix and characterizes the number and rates of active duty U.S. Army injuries as measured by the OMNI compared to other matrices.

MATERIALS AND METHODS

A team of researchers including physical therapists, physician assistants, occupational therapists, physicians, and epidemiologists developed the OMNI. The OMNI utilizes the commonly accepted injury definition inclusive of any anatomical complaint resulting in pain or dysfunction and categorizes injuries from the G, M, S, and T codes. The OMNI follows the CDC's matrix structure with three body region levels, each becoming more specific, and adds two levels called Description of the Injury. Additionally, the OMNI categorizes injuries as Injury Type (Acute, Overuse, Either, or Not Applicable), NMSKI-Type (NMSKI, NMSKI that could be caused by occupational/training tasks, and not an NMSKI), and a miscellaneous category that demarks injuries as Superficial, Blood Vessels, and/or Internal Organs. The different grouping methods in the OMNI provide standardization for many possible injury case definitions. The OMNI allows these injury categories to be included/excluded in a standardized fashion to meet the researchers' scientific questions. To enumerate the number of NMSKI that would be captured by the available matrices, the OMNI, the CDC's matrix, and the U.S. Army Public Health Center's (APHC) Taxonomy of Injuries were applied to active duty Army outpatient population data and all incident NMSKI diagnostic codes entered in electronic medical provider encounters for calendar years 2017 and 2018.

RESULTS

Using the OMNI resulted in the capture of over 800,000 more injuries than the CDC's matrix and over 200,000 more than the APHC Taxonomy. The NMSKI rate utilizing the OMNI was 193 per 100 soldier-years in 2017 (892,780 NMSKI) compared to 23 per 100 soldier-years for the CDC's matrix, and 141 per 100 soldier-years for the APHC Taxonomy.

CONCLUSION

The OMNI provides an updated standardized method of assessing injuries, particularly in occupational military injury research, that can be utilized for Military Performance Division of injury across many countries and still allow for replication of methods and comparison of results. Additionally, the OMNI has the capacity to capture a greater burden of injury beyond what is captured by other available matrices.

Lower Physical Fitness Is Associated with Injuries in Iranian National Futsal Teams: A Prospective Study

Background: Several studies have investigated risk factors for injury in different sports. However, little scientific information is available in relation to futsal injuries. Objectives: This study prospectively analyzed the influence of physical fitness parameters on the occurrence of futsal injuries in Iranian national teams. Methods: Prior to the season, all 55 players of 3 Iranian national futsal teams took part in a series of tests for physical fitness parameters such as cardio-respiratory fitness, muscle strength, body composition, flexibility, agility, and speed. Team physicians recorded all injuries, medical attention, and time loss due to the injury throughout the match and training sessions. Results: During 18 months, 54 futsal injuries were sustained by 32 players. Injured players had poorer performance at baseline in agility, speed, and vertical jump than players who did not incur an injury during the season. Lower maximal oxygen uptake (VO2max) values were associated with a higher injury risk. No differences between injured and uninjured players were observed in age, anthropometric data, flexibility, and lower extremity strength. Conclusions: Some physical fitness parameters were associated with the risk of injuries in futsal. Therefore, improving physical fitness might help to reduce the number of futsal injuries.

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.

Risk factors for musculoskeletal injuries in military personnel: a systematic review with meta-analysis

OBJECTIVE

To investigate the risk factors for musculoskeletal injuries in military personnel.

METHODS

A systematic literature search was carried out in August 2019 and updated in July 2020 without language or time filters. The inclusion criteria were prospective studies that investigated the risk factors for injuries in military personnel. Only risk factors analyzed by at least ten studies were selected for the meta-analysis. For data analysis, the RevMan5.3 program was used to compare the number of participants with injuries between high- or low-risk groups. The measurement of dichotomous variables was one of the selected parameters for the analysis, as well as the Mantel-Haenszel statistical method, random-effects model, and analysis with a relative risk (RR) and 95% confidence interval for the included studies.

RESULTS

A total of 2,629 studies were identified through databases. Thirty-four studies met the inclusion criteria. The groups considered at risk were the oldest [RR = 1.22; (95% CI 1.06-1.41)], with overweight or obesity [RR = 1.27; (95% CI 1.08-1, 48)], with previous injuries [RR = 1.15; (95% CI 1.01-1.30)], and with the worst performance in running tests of 1,600-3,200 m [RR = 1.87; (95% CI 1.28-2.71)]. Gender, ethnicity, and smoking were not associated with injuries. However, a subgroup analysis showed that among studies with a follow-up of fewer than 12 months, women presented RR = 2.44 (95% CI 1.65-3.60) more likely to develop injuries.

CONCLUSION

Age, overweight or obesity, previous injuries, and performance in the 1600-3200 m run are associated with an increased risk of injury in the military.

Differences in lower-extremity kinematics between the male military personnel with and without plantar fasciitis

OBJECTIVE

To evaluate the factors that influence gait by comparing lower extremity kinematics during the stance phase of the gait cycle between individuals with and without plantar fasciitis.

DESIGN

A cross-sectional study.

SETTING

Motion analysis research laboratory.

PARTICIPANTS

Thirty subjects with plantar fasciitis and 30 aged-matched controls.

MAIN OUTCOME MEASURE(S)

Range of motion of the lower extremity and multi-segment foot during gait using a three-dimensional motion analysis system.

RESULTS

The plantar fasciitis group showed significant differences in motion in the multi-segment foot, ankle, knee, and hip from the control group during various subphases of the stance phase. Specifically, relative to the control group, the plantar fasciitis group had more rearfoot adduction, forefoot eversion, ankle abduction, and hip abduction. They also had less midfoot dorsiflexion, forefoot dorsiflexion, knee extension, knee external rotation, and hip extension (all Ps < 0.05).

CONCLUSIONS

Individuals with plantar fasciitis exhibited more flexibility in the ankle-foot complex and poorer quality of lower-extremity movement than the group that did not have plantar fasciitis. Thus, differences in structures in both the ankle-foot complex as well as those in the hip and knee joints appear to be associated with the presence of plantar fasciitis.

Overuse-Related Injuries of the Musculoskeletal System: Systematic Review and Quantitative Synthesis of Injuries, Locations, Risk Factors and Assessment Techniques

Overuse-related musculoskeletal injuries mostly affect athletes, especially if involved in preseason conditioning, and military populations; they may also occur, however, when pathological or biological conditions render the musculoskeletal system inadequate to cope with a mechanical load, even if moderate. Within the MOVIDA (Motor function and Vitamin D: toolkit for risk Assessment and prediction) Project, funded by the Italian Ministry of Defence, a systematic review of the literature was conducted to support the development of a transportable toolkit (instrumentation, protocols and reference/risk thresholds) to help characterize the risk of overuse-related musculoskeletal injury. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) approach was used to analyze Review papers indexed in PubMed and published in the period 2010 to 2020. The search focused on stress (overuse) fracture or injuries, and muscle fatigue in the lower limbs in association with functional (biomechanical) or biological biomarkers. A total of 225 Review papers were retrieved: 115 were found eligible for full text analysis and led to another 141 research papers derived from a second-level search. A total of 183 papers were finally chosen for analysis: 74 were classified as introductory to the topics, 109 were analyzed in depth. Qualitative and, wherever possible, quantitative syntheses were carried out with respect to the literature review process and quality, injury epidemiology (type and location of injuries, and investigated populations), risk factors, assessment techniques and assessment protocols.

Factors associated with Achilles tendon pain in cyclists in eastern province of Saudi Arabia

BACKGROUND:

Cyclists are predisposed to different types of injuries whose patterns and distribution change over time. During bicycling, the high demand on lower extremities to produce speed places high load on the legs resulting in overuse injuries of which pain in the Achilles tendon is one. This study assessed Achilles tendon pain in cyclists in the eastern province of Saudi Arabia.

MATERIALS AND METHODS:

This was a cross-sectional study of active cyclists in the eastern province of Saudi Arabia. Data were collected using validated and pretested web-based self-administered questionnaire. Of the 511 cyclists invited, 311 completed the questionnaire yielding 60.62% response rate. SPSS was used for data entry and analysis. Descriptive statistics included calculation of frequencies and percentages for categorical variables, and median, mean and standard deviation for continuous variables. Chi-square test measured the associations between Achilles pain and various risk factors. Student's t-test, or Mann–Whitney test as appropriate, was used to compare continuous variables.

RESULTS:

Ten percent of mature and 9.1% professional cyclists reported that they had Achilles tendon pain. The pain was reported by significantly higher proportion of cyclists who raced (25%) and cyclists who rode mountain bicycles off-road (60.0%); average duration of the Achilles tendon pain was 7 days. Of the cyclists who had Achilles tendon pain, 32.1% reported that the pain increased when they were in running load and 28.6% reported increased pain in cycling load. Most cyclists described the pain as mild (67.9%) and moderate (32.1%). Overweight and underweight cyclists reported significantly higher rates of Achilles tendon pain (60% and 12.5%) compared to other body mass index classes.

CONCLUSION:

Achilles tendon pain commonly affects both amateur and professional cyclists. The study underpins the importance of a gradual increase in the training load, proper conditioning, bike fitting, and the maintenance of ideal body weight of cyclists to prevent Achilles tendon pain.

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.

Physical Performance Measures of Flexibility, Hip Strength, Lower Limb Power, and Trunk Endurance in Healthy Navy Cadets: Normative Data and Differences Between Sex and Limb Dominance

ABSTRACT

Lopes, TJA, Simic, M, Alves, DdS, Bunn, PdS, Rodrigues, AI, Terra, BdS, Lima, MdS, Ribeiro, FM, Vilão, P, and Pappas, E. Physical performance measures of flexibility, hip strength, lower limb power, and trunk endurance in healthy navy cadets: Normative data and differences between sex and limb dominance. J Strength Cond Res 35(2): 458-464, 2021-The objectives were to provide normative data on commonly used physical performance tests that may be associated with musculoskeletal injuries in Navy cadets and assess for sex and limb dominance differences. A large cohort of Navy cadets were assessed for physical performance tests of flexibility (ankle dorsiflexion range of motion and sit and reach), isometric hip strength, lower limb power (single-leg hop), and trunk endurance (plank and side plank tests). Besides providing normative data tables, sex and limb dominance differences were assessed by a 2-way mixed analysis of variance. A total of 545 Brazilian Navy cadets (394 men) representing 79% of the cadets in the Academy participated. Normative reference values were reported as mean ± SD, 95% confidence interval and percentiles. For tests of muscle strength, power, and endurance, men performed better than women (p < 0.001). For flexibility tests, women achieved greater distances than men for the sit and reach test (p < 0.001), but no difference for ankle dorsiflexion (p = 0.51). Overall, there were no clinically relevant differences between limbs. In conclusion, normative data for commonly used physical performance tests were provided. Although no clinically relevant side-to-side differences were found, men presented higher values for lower limb strength and power, as well as trunk endurance than women, whereas women demonstrated increased flexibility. Valuable normative data are provided to professionals who work with young, active populations from the injury prevention or rehabilitation perspective because the current study may help professionals to identify athletes or cadets whose performance is outside the normative values and may be at risk for injury.

Utility of Kinetic and Kinematic Jumping and Landing Variables as Predictors of Injury Risk: A Systematic Review

Purpose

Jump-landing assessments provide a means to quantify an individual’s ability to attenuate ground reaction forces, generate lower limb explosive power and maintain joint alignment. In order to identify risk factors that can be targeted through appropriate training interventions, it is necessary to establish which (scalar) objective kinetic, kinematic, and performance measures are most associated with lower-extremity injury.

Methods

Online searches of MEDLINE, SCOPUS, EBSCOHost, SPORTDiscus and PubMed databases were completed for all articles published before March 2020 in accordance with PRISMA guidelines.

Results

40 articles investigating nine jump-landing assessments were included in this review. The 79% of studies using drop jump (n = 14) observed an association with future injury, while only 8% of countermovement jump studies (n = 13) observed an association with injury risk. The 57% of studies using unilateral assessments found associations with risk of injury (n = 14). Studies using performance measures (jump height/distance) as outcome measure were only associated with injury risk in 30% of cases. However, those using kinetic and/or kinematic analyses (knee abduction moment, knee valgus angle, knee separation distance, peak ground reaction force) found associations with injury in 89% of studies.

Conclusion

The landing element of jump-landing assessments appears to be superior for identifying individuals at greater risk of injury; likely due to a closer representation of the injury mechanism. Consequently, jump-landing assessments that involve attenuation of impact forces such as the drop jump appear most suited for this purpose but should involve assessment of frontal plane knee motion and ground reaction forces.

Short-Term Core Strengthening Program Improves Functional Movement Score in Untrained College Students

Functional movement is an important part of developing athletes’ but also untrained individuals’ performance. Its monitoring also proved useful in identifying functional limitations and asymmetries, and also in determining the intervention effects. The quasi-experimental pre-test post-test study investigated the effects of core stability training program on the Functional Movement Screen (FMS) score in untrained students after six weeks. The intervention (INT) and control (CG) groups included 73 and 65 male students, respectively. Functional movement patterns were evaluated using the FMS including seven components scores representing seven basic functional patterns. Both groups significantly improved almost all FMS components scores, but the INT increased the mean performance of the hurdle step (partial ŋ² × 100 = 4%, p = 0.02), in-line lunge (partial ŋ² × 100 = 3%, p = 0.05), rotatory stability (partial ŋ² × 100 = 4%, p = 0.02) and total FMS (partial ŋ² × 100 = 3%, p = 0.04) significantly more than the CG. This justifies that core strengthening can improve FMS in untrained individuals even with the short duration programs.

Can Achilles and patellar tendon structures predict musculoskeletal injuries in combat soldiers?

Aiming to investigate whether Achilles tendon (AT) structure and patellar tendon (PT) structure are risk factors for musculoskeletal injuries in combat soldiers, 168 participants were recruited from an infantry commander's course. The AT and PT were examined pre-course using UTC to capture the structure of four echo-type fibers (I-IV). All injuries were assessed by military physicians pre-course and throughout the 14-week course. Soldiers who were injured during the course had a significantly higher pre-course prevalence of AT and PT echo-type III and echo-type IV compared to soldiers that were not injured during the course. Variables that were found to be associated with injured/non-injured participants were echo-type III + IV of the PT (OR = 1.44, 95% CI = 1.24-1.68) and echo-type III of the AT (OR = 1.69, 95% CI = 1.35-2.12). ROC analyses showed that the best model, exhibiting both high sensitivity and low specificity, was that participants with PT echo-type III + IV > 10% or AT echo-type III >8.5% had the highest risk of being injured during the course. In conclusions, the tendon structure at the beginning of high-intensity activity or physical training program might be a risk factor for subsequent injury during the course. Soldiers and high-level athletes should be aware of the cutoff points for fiber types in tendon structure that might put them at high risk for future injury. At-risk soldiers/athletes should be provided with an intervention program before they start their training program, with the aim of improving the tendon structure and preventing subsequent injury.

Body mass index and waist-to-hip ratio misclassification of overweight and obesity in Chinese military personnel

BACKGROUND

The rising prevalence of obesity in military personnel has raised great concerns. Previous studies suggest that body mass index (BMI)- and waist-to-hip ratio (WHR)-based obesity classifications in US military personnel and firefighters have high false negative and subsequently cause obesity misclassification.

OBJECTIVE

To determine whether BMI and WHR could reflect the fat mass of Chinese military personnel.

METHODS

Three hundred fifty-three male Chinese military personnel and 380 age-matched male adults were recruited. Obesity classification was defined by BMI, WHR, and body fat percentage (BFP).

RESULTS

Chinese military personnel had extremely low obesity rate determined by either BFP (0.3%) or BMI (0.6%). By combining overweight and obese individuals, BMI- and WHR-determined prevalence of overweight/obesity was 22.4% and 17.0% compared to BFP-based standard (4.0%) (P < 0.05). In reference to BFP, BMI and WHR have high false-positive rate compared to the control group. Further analysis showed that Chinese military personnel consisted of high percentage of BFP^lowBMI^high and/or BFP^lowWHR^high subpopulations. Eighty-one percent of BMI^high and 78.3% of WHR^high of them were BFP low.

CONCLUSIONS

Chinese military personnel has extremely low obesity rate. BMI and WHR have high false-positive rates in reference to BFP, which cannot accurately reflect the mass of adipose tissue and leads to obesity misclassification.

Markers of Bone Health and Impact of Whey Protein Supplementation in Army Initial Entry Training Soldiers: A Double-Blind Placebo-Controlled Study

Training civilians to be soldiers is a challenging task often resulting in musculoskeletal injuries, especially bone stress injuries. This study evaluated bone health biomarkers (P1NP/CTX) and whey protein or carbohydrate supplementations before and after Army initial entry training (IET). Ninety male IET soldiers participated in this placebo-controlled, double-blind study assessing carbohydrate and whey protein supplementations. Age and fat mass predicted bone formation when controlling for ethnicity, explaining 44% (p < 0.01) of bone formation variations. Age was the only significant predictor of bone resorption (p = 0.02) when controlling for run, fat, and ethnicity, and these factors together explained 32% of the variance in bone resorption during week one (p < 0.01). Vitamin D increased across training (p < 0.01). There was no group by time interaction for supplementation and bone formation (p = 0.75), resorption (p = 0.73), Vitamin D (p = 0.36), or calcium (p = 0.64), indicating no influence of a supplementation on bone biomarkers across training. Age, fitness, fat mass, and ethnicity were important predictors of bone metabolism. The bone resorption/formation ratio suggests IET soldiers are at risk of stress injuries. Male IET soldiers are mildly to moderately deficient in vitamin D and slightly deficient in calcium throughout training. Whey protein or carbohydrate supplementations did not affect the markers of bone metabolism.

What is the impact of fitness on injury risk during police academy training? A retrospective cohort study

BACKGROUND

In the conduct of their daily duties, law enforcement officers (LEO) are often required to perform dynamic, physically demanding tasks with little or no notice, sometimes at maximal levels of exertion. Given these requirements, training for prospective LEOs must be rigorous enough to ensure that when trainees graduate, they are competent in their response to crisis and resilient enough to maintain this for the span of their career. Therefore, based on previously reported effectiveness of fitness testing in predicting injury risk in predominantly military settings, the aim of this study was to investigate relationships between a physical ability test (PAT) and risk of injury during police recruit training.

METHODS

Retrospective PAT results and trainee injury records were obtained from a national police department and Mann-Whitney U tests were performed to investigate fitness differences between trainees who were, or were not, injured. Significant results were tested for effect size using Cliff's delta (CD).

RESULTS

Significant differences in mean performance between groups existed for the following PAT components: pushups (injured mean 32.94 ± 8.66 reps, uninjured mean 35.67 ± 9.04 reps, p = 0.01 CD + 0.11) and right-hand grip strength (injured mean 49.61 ± 12.51 kg, uninjured mean 52.12 ± 11.17 kg, p = 0.042 CD + 0.22) for all injuries; vertical jump height (injured mean 51.75 ± 7.54 cm, uninjured mean 55.06 ± 8.19 cm, p = 0.032 CD + 0.41) for lower limb injuries, and all measures of grip strength for trunk injury.

CONCLUSIONS

The results of this study suggest that a significant relationship between some PAT fitness components and injury risk exists during police recruit training.

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.

The Association between Increased Body Mass Index and Overuse Injuries in Israel Defense Forces Conscripts

OBJECTIVES

To examine the association between body mass index (BMI) and overuse injuries (OI) among Israel Defense Forces soldiers, in different corps.

METHODS

Conscripts between 2003 and 2012, infantry, armored corps and intelligence corps (controls) were studied. OI data were taken from computerized patient records. The BMI was classified as underweight, low-normal (18.5-21.9), high-normal (22-24.9), overweight and obese. Multivariate analysis was performed using logistic regression.

RESULTS

There were 73,640 soldiers: 42,506 infantry, 20,781 armor and 10,353 intelligence. OI rates were 52.2, 51.6 and 27%, respectively. OI rate was directly proportional to BMI in all groups (relative risk compared to low-normal, underweight: 0.97, high-normal: 1.05, overweight: 1.11, obese: 1.19, p < 0.05 for all), increased height and younger age. By logistic regression, OI were significantly associated with training group, higher BMI, increased height, younger age, lower education, lower socioeconomic status and lower psychotechnical grading. Throughout the BMI range, each additional unit of BMI was associated with a 2% OI increase.

CONCLUSIONS

Higher BMI was associated with a higher rate of OI in all groups. Therefore there is no point in differentially assigning recruits based on BMI.

Incidence and Risk Factors of Upper Extremity Injuries in Young Adult Men: A Nationwide Registry-Based Study of 128,714 Conscripts

Introduction

Injuries are the major cause of morbidity and loss of active training days in military populations. Previous investigations have mainly focused on lower extremities. This study evaluated the incidence, diagnosis, and risk factors of upper extremity injuries requiring hospitalization in a large cohort of Finnish conscripts during a 5-year period.

Materials and Methods

A total of 128,714 male military conscripts, who served 6–12 months in compulsory military service, were studied. Injury hospitalization data were obtained from the National Hospital Discharge Register. The main outcome variables were hospitalization due to any injuries to the upper extremity and hospitalization due to traumatic shoulder dislocation. Background variables for risk factor analysis included length of military service, age, body height and weight, body mass index, and physical fitness.

Results

Overall person-based incidence rate for hospitalization due to upper extremity injury was 743 (95% confidence interval [CI]: 697–791) per 100,000 conscripts per year. Shoulder joint dislocation was the most common injury: incidence rate of 103 (95% CI: 86–122) per 100,000 conscripts per year. Trend during follow-up years 1998–2002 was decreasing concerning on any upper extremity injuries (odd ratios [OR] 0.90; 95% CI: 0.86–0.95, P &lt; 0.001). Body mass index &gt; 25 increased a risk for any injuries of the upper extremity (OR 1.29; CI 95%: 1.10–1.51) and, especially, for shoulder joint dislocation (OR 1.88; CI 95%: 1.26–2.80).

Conclusions

Overweight young men were at greater risk for upper extremity injuries. The incidence rate of traumatic shoulder joint dislocation was considerably higher than reported previously. In conclusion, preventive measures such as reducing the body weight of overweight young men should play an important role in reducing the incidence of upper extremity injuries.

The Association Between Fitness Test Scores and Musculoskeletal Injury in Police Officers

A police officer’s career is hazardous and physically demanding. In order to perform occupational tasks effectively and without injury, officers require adequate physical abilities. The aim of this study was to investigate the relationship between scores on several fitness tests and musculoskeletal injury in a group of municipal police officers. This retrospective study used existing data to examine the relationship between risk of injury and fitness test performance. Injured and uninjured police officers scored significantly differently on several fitness measures. A multivariate regression indicated that a combination of age, sex, number of pull ups completed and maximal oxygen consumption (VO_2max) best explained injury risk. Additionally, the findings indicated an interaction between sex and VO_2max, and so the effect of VO_2max on injury risk cannot be understood without accounting for sex.

Remarkable increase of musculoskeletal disorders among soldiers preparing for international missions - comparison between 2002 and 2012

Background

Musculoskeletal disorders (MSD) are common among soldiers and constitute the most common reason for discontinuing military service within different military populations worldwide. The aims of this study were to investigate the prevalence of musculoskeletal disorders in two cohorts, 10 years apart, in the Swedish Armed Forces, to explore differences between these cohorts and to determine associated factors with MSD.

Method

Comparative cross-sectional study. Participants were recruited from the Swedish Armed Forces, i.e. soldiers preparing for international missions in 2002 and 2012. A total of 961 soldiers, 7% women, participated in the study.

Data were collected using the Musculoskeletal Screening Protocol (MSP), which includes questions regarding prevalence of MSD in ten anatomical locations (neck, upper back, low back, shoulders, elbow, hand, hip, knee, lower limb and foot). An additional five questions concern perceived self-rated health, i.e. how the respondent perceives their own physical body, mental health, social environment, physical environment and work ability.

Results

Over a ten-year period, both point prevalence and one-year prevalence of MSD in any body part increased significantly, with point prevalence increasing from 7.1 to 35.2% (p < 0.001) and one-year prevalence from 27.9 to 67.9% (p < 0.001). The knee was the most common anatomic location for MSD in both cohorts. Across each anatomical location (neck, upper back, low back, shoulders, elbow, hand, hip, knee, lower leg and foot), both point prevalence (p < 0.039) and one-year prevalence (p < 0.005) increased significantly from 2002 to 2012.

Most soldiers reported good to excellent perceived health, i.e. self-perception of their physical body, mental health, physical and social environments, and work ability.

The odds of reporting one-year prevalence of MSD in any body part was 5.28 times higher for soldiers in Cohort 2012, 1.91 times higher in age group 31–40 and 2.84 times higher in age group 41 and above.

Conclusions

The prevalence of MSD increased remarkably over a ten-year period among Swedish soldiers preparing for international missions. With increasing age as one risk factor, systematic monitoring of MSD throughout the soldiers’ careers and implementation of targeted primary-to-tertiary preventive programs are thus important.

Systematic Review of the Association Between Physical Fitness and Musculoskeletal Injury Risk: Part 3-Flexibility, Power, Speed, Balance, and Agility

de la Motte, SJ, Lisman, P, Gribbin, TC, Murphy, K, and Deuster, PA. Systematic review of the association between physical fitness and musculoskeletal injury risk: part 3-flexibility, power, speed, balance, and agility. J Strength Cond Res 33(6): 1723-1735, 2019-We performed a systematic review and evaluation of the existing scientific literature on the association between flexibility, power, speed, balance, and agility, and musculoskeletal injury (MSK-I) risk in military and civilian populations. MEDLINE, EBSCO, EMBASE, and the Defense Technical Information Center were searched for original studies published from 1970 to 2015 that examined associations between these physical fitness measures (flexibility, power, speed, balance, and agility) and MSK-I. Methodological quality and strength of the evidence were determined after criteria adapted from previously published systematic reviews. Twenty-seven of 4,229 citations met our inclusion criteria. Primary findings indicate that there is (a) moderate evidence that hamstring flexibility, as measured by performance on a sit-and-reach test or active straight leg raise test assessed with goniometry, and ankle flexibility, assessed with goniometry, are associated with MSK-I risk; (b) moderate evidence that lower body power, as measured by performance on a standing broad jump or vertical jump with no countermovement, is associated with MSK-I risk; (c) moderate evidence that slow sprint speed is associated with MSK-I risk; (d) moderate evidence that poor performance on a single-leg balance test is associated with increased risk for ankle sprain; and (e) insufficient evidence that agility is associated with MSK-I risk. Several measures of flexibility, power, speed, and balance are risk factors for training-related MSK-I in military and civilian athletic populations. Importantly, these findings can be useful for military, first responder, and athletic communities who are seeking evidence-based metrics for assessing or stratifying populations for risk of MSK-I.

Ability of fitness testing to predict injury risk during initial tactical training: a systematic review and meta-analysis

Objective

Tactical personnel (Military, Law Enforcement, Emergency Responders) require physical fitness levels sufficient for training and occupational duty. Physical conditioning aimed at increasing fitness levels during training presents an injury risk, but unfit trainees may struggle to meet occupational performance standards, further increasing injury risk to themselvesor others. Therefore, the aim of this review was to determine if fitness, asquantified by tactical fitness tests, effectively predicts injury risk during training.

Methods

Literature databases were search and relevant articles extracted. 27 Publications were included for qualitative review and seven studies reporting a timed run were included in meta-analysis.

Results

The combined risk ratio was 2.34 (95% CI 2.02 to2.70). Muscular endurance tests were less conclusive in their predictive abilities. Functional strength or power tests were effective predictors, but few studies reported on strength or power, indicating a need for further study inthis area.

Conclusions

The meta-analysis results are supported by the occupational relevance of run tests; tactical trainees are required to perform frequent bouts of distance weight bearing activity. However, given the diverse physical requirements of tactical personnel, measures of strength and power should alsobe evaluated, especially given their effectiveness in the studies that included these measures.

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.

Management of acute musculoskeletal pain (excluding low back pain): protocol for a systematic review and network meta-analysis of randomised trials

INTRODUCTION

Acute, non-low back-related musculoskeletal pain is common and associated with significant socioeconomic costs. No review has evaluated all interventional studies for acute musculoskeletal pain, which limits attempts to make inferences regarding the relative effectiveness of treatments.

METHODS AND ANALYSIS

We will conduct a systematic review of all randomised controlled trials evaluating therapies for acute musculoskeletal pain (excluding low back pain). We will identify eligible, English-language, trials by a systematic search of the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Medline, Physiotherapy Evidence Database (PEDro) and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to February 2018. Eligible trials will: (1) enrol patients presenting with acute, non-low back-related musculoskeletal pain (duration of pain ≤4 weeks), and (2) randomise patients to alternative interventions or an intervention and a placebo/sham arm. Fractures will be considered ineligible, unless they are non-surgical and therapy is directed at pain relief. Pairs of reviewers will, independently and in duplicate, screen titles and abstracts of identified citations, review the full texts of potentially eligible trials and extract information from eligible trials. We will use a modified Cochrane instrument to evaluate risk of bias. Disagreements will be resolved through discussion to achieve consensus. We will use the Grading of Recommendations Assessment, Development and Evaluation approach to evaluate the quality of evidence supporting treatment effects. When possible, we will conduct: (1) in direct comparisons, a random-effect meta-analysis to establish the effectiveness of therapeutic interventions on patient-important outcomes; and (2) multiple treatment comparison meta-analysis to assess the relative effects of treatments. We will use a priori hypotheses to explain heterogeneity between studies. We will use STATA V.14.2 for all analyses.

ETHICS AND DISSEMINATION

No research ethics approval is required for this systematic review, as no confidential patient data will be used. The results of this systematic review will be disseminated through publication in a peer-reviewed journal, conference presentations and will inform a clinical practice guideline.

PROSPERO REGISTRATION NUMBER

CRD42018094412.

Physical and psychological predictors on pain intensity in conscripts with plantar fasciitis

BACKGROUND

Plantar fasciitis is commonly found among the physically active population, including conscripts. Some studies have reported that being overweight and having psychological symptoms contribute to pain from plantar fasciitis. However, there is a lack of information regarding the physical predictors, and more research is needed to determine the relationship between such predictors and pain intensity from plantar fasciitis in conscripts.

OBJECTIVE

To determine which physical and psychological variables act as predictors of pain intensity among Thai novice conscripts with plantar fasciitis.

METHODS

Two hundred and seventy Thai novice conscripts without musculoskeletal pain completed the Depression, Anxiety and Stress Scale short version and then received baseline assessment of ankle dorsiflexion angle, ankle plantarflexor strength, and quality of lower extremity movement from a physical therapist. After 10 weeks of military training, 71 of these Thai conscripts developed pain from plantar fasciitis. Multiple linear regression analysis with the forward stepwise method was used to explore the predictors of pain intensity due to plantar fasciitis.

RESULTS

Using a forward regression analysis, anxiety (B=0.13; 95% CI, 0.06-0.20; p<0.01) and quality of movement score (B=0.87; 95% CI, 0.28-1.47; p=0.01) were significant predictors of pain intensity. The regression model with these predictors explained 25% of the variability in pain intensity from plantar fasciitis.

CONCLUSION

Higher scores of anxiety and movement quality on the lateral step-down task were associated with pain intensity from plantar fasciitis after the completion of a 10-week military program. However, lower ankle dorsiflexion angle and ankle plantarflexor strength did not predict pain intensity.

Lean and mean? Associations of level of performance, chronic injuries and BMI in sport climbing

Objectives

To assess possible associations between performance level (achieved level of difficulty), chronic injuries and body mass index (BMI) in sport climbing.

Method

Retrospective survey.

Setting

Web-based questionnaire.

Participants

667 active climbers (385 reported having chronic injuries).

Outcome measure

BMI, performance level in sport climbing, onset of a climbing-related injury, preferred style of climbing, education, gender.

Statistics

Descriptive statistics and general linear model(GLM) performed with SPSS V.25 for windows.

Result

No associations were found between level of performance in sport climbing, onset of a climbing-related injury, preferred style of climbing, education, gender and BMI.

Conclusion

BMI is not associated with climbing-related chronic injury or level of performance in climbing. The average BMI of climbers up to the elite level is similar to that of a lower rate of performance.

Clinical relevance

The findings in this study suggest that there is no need for maintaining a low BMI to be able to reach elite levels in climbing.

The association between the functional movement screen outcome and the incidence of musculoskeletal injuries: A systematic review with meta-analysis

OBJECTIVE

To systematically review the literature investigating the association between the Functional Movement Screening (FMS™) score and musculoskeletal injuries in physical exercise based on relative risk (RR).

METHODS

A systematic literature search was carried out in July 2018 in MEDLINE, LILACS, SCOPUS, SPORTDiscus, CINAHL and Web of Science databases. Reference lists were explored to find studies that examined the association between FMS™ and injuries. The following data were extracted from the studies: the participants' profile, sample size, classification of musculoskeletal injuries, follow-up time and RR. Participants with FMS™ score <13-14 were considered as "high risk" depending on used cut-off. The Mantel-Haenszel Test with random-effect model and the RR measure was performed. The Begg Test was used to analyze the publication bias.

RESULTS

A total of 1658 studies were retrieved from the databases and 20 were selected. A meta-analysis of 964 injuries in 2227 high-risk participants and 1719 injuries in 5756 low-risk participants showed that individuals at "high risk" by FMS™ had a RR = 1.51 (95%CI = 1.35-1.69) of developing injuries.

CONCLUSIONS

Individuals classified as "high risk" by FMS™ are 51% more likely to be affected by injury than those classified as having low risk, but the level of evidence is very low.

Can anthropometric, body composition, and bone variables be considered risk factors for musculoskeletal injuries in Brazilian military students?

Background

Musculoskeletal injuries are the main cause of premature discharge from military service and can sometimes lead to permanent disabilities. Some intrinsic risk factors are well discussed in the literature. However, the relation between body composition variables and the risk for musculoskeletal injury is not well known or recognized.

Methods

This prospective study evaluated 205 Brazilian military students. At the beginning of military service, health status and sports experience prior to military service were registered. Anthropometric variables were evaluated, and bone and body composition variables were measured using dual-energy X-ray absorptiometry. The occurrence of musculoskeletal injuries throughout the year was registered at the military physiotherapy service. At the end of 1 year of follow-up, risk factors were analysed by comparing the variables between the injured and non-injured students.

Results

No difference in previous health status was found between injured and non-injured groups, whereas sports experience prior to military service was identified as a protective factor (Odds Ratio (OR) 0.323; 95% CI: 0.108–0.968; p = 0.044). Anthropometric, bone, and body composition variables could not be identified as risk factors for musculoskeletal injuries in Brazilian military students.

Conclusion

Anthropometric, bone, and body composition variables could not be considered risk factors for musculoskeletal injuries in Brazilian military students.

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.