Gender differences in musculoskeletal injury rates: a function of symptom reporting?

Sex Differences in the Prevalence of Meibomian Gland Dysfunction: A Mini Review

PURPOSE

In this review, we aimed to investigate the literature on sex-specific prevalence of meibomian gland dysfunction (MGD) and to determine whether women or men are more at risk for MGD.

METHODS

A search was conducted on PubMed using the terms: (Sex OR Gender OR prevalence) AND (Meibomian gland).

RESULTS

Twenty-four relevant studies on MGD prevalence were identified, including 10 population-based and 14 hospital-based studies. Among the population-based studies, five studies reported higher rates among men, three studies found no differences, and one study observed higher rates among women. In the hospital-based studies, 10 studies reported no difference, two found higher rates among men, and one found higher among women. In the reviewed literature, there was a considerable variation between studies in terms of quality, sample size, age ranges, diagnostic criteria.

CONCLUSIONS

While most of the population-based studies suggest a higher prevalence among men, the majority of clinic-based studies show no significant difference. Further research with larger samples and standardized criteria is needed to determine whether men are indeed more susceptible to MGD.

Determinants of Intention to Disclose Musculoskeletal Injury in Adolescent Athletes

CONTEXT

Although research indicates that the key to minimizing the effect of musculoskeletal injury, improving care, and mitigating long-term effects is to improve early injury care seeking, little is known about barriers to early musculoskeletal injury disclosure and care seeking.

OBJECTIVE

To identify which determinants predicted sport-related musculoskeletal (MSK) injury disclosure by adolescent athletes.

DESIGN

Cross-sectional study.

SETTING

Online survey.

PATIENTS OR OTHER PARTICIPANTS

A total of 564 adolescent athletes (58% male, age = 15.81 ± 1.8 years).

MAIN OUTCOME MEASURE(S)

Online survey exploring determinants of age, gender, race, socioeconomic status, injury knowledge, attitudes, perceived social norms, and perceived behavioral control surrounding MSK injury disclosure, intention to disclose MSK injury, and actual behavior of disclosing MSK injury.

RESULTS

Of the respondents, 457 (80.2%) reported having sustained ≥1 (mean = 3.2 ± 2.2; range = 1-10) MSK injuries related to sport. Those who endorsed having experienced an MSK injury disclosed not reporting or purposefully hiding 77% of their suspected MSK injuries. Several factors influenced a high intention to disclose MSK injury. Specifically, for each unit increase in total MSK injury knowledge (Exp[β] = 1.061, β=0.054, P = .020, 95% CI = 1.031, 1.221) and attitude (Exp[β] = 1.070, β = 0.064, P < .001, 95% CI = 1.027, 1.115) score, 6% and 7% increases in the likelihood of a high intention to disclose an MSK injury, respectively, were observed. Moreover, for each unit increase in the social norm score (Exp[β] = 1.178, β=0.164, P < .001, 95% CI = 1.119, 1.241), an 18% increase in the likelihood of a high intention to disclose an MSK injury was noted.

CONCLUSIONS

Designing interventions geared toward increasing the knowledge of signs and symptoms of MSK injury, improving attitudes surrounding disclosure, and better understanding the social context of disclosing MSK injuries may improve MSK injury disclosure behavior and reduce the associated social and economic burdens of these injuries.

Hip Range of Motion During Passive and 1-Leg Exercises Is Greater in Women: A Meta-analysis and Systematic Review

PURPOSE

To summarize sex-related differences in hip range of motion (ROM), including flexion, extension, abduction, adduction, internal rotation, and external rotation.

METHODS

We performed a systematic search of 3 databases (PubMed, CINAHL [Cumulative Index to Nursing and Allied Health Literature], and Embase). The search terms were as follows: hip, pelvis, range of motion, kinematic, men, and women. Included studies reported sex-specific data on hip ROM in healthy, uninjured adults. To generate hip ROM mean differences, a DerSimonian-Laird random-effects model was used. Effect sizes were pooled for each exercise. Subgroup analyses compared hip ROM by physical activity group: passive ROM, 1-leg hop or jump, 2-leg hop or jump, 2-leg drop or landing, 1-leg squat, 2-leg squat, walking, and jogging/running. Positive effect sizes represent greater ROM in women.

RESULTS

Thirty-eight studies with 3,234 total subjects were included; of these subjects, 1,639 were women (50.1%). The mean age was 25.3 years. An effect difference was considered statistically significant if P < .05 and clinically significant if the mean difference was greater than 4.0°. Women showed statistically and clinically significantly greater hip flexion in passive ROM (mean difference, 6.4°) and during the 1-leg hop or jump exercise (mean difference, 6.5°). Women also showed statistically and clinically significantly greater hip adduction during the 1-leg hop or jump (mean difference, 4.5°) and 1-leg squat (mean difference, 4.4°) exercises, as well as statistically and clinically significantly greater hip internal rotation in passive ROM (mean difference, 8.2°). In contrast, men showed statistically and clinically significantly greater flexion during the 2-leg hop or jump exercise (mean difference, -9.1°). No clinically significant differences in extension, abduction, or external rotation were found between women and men.

CONCLUSIONS

On average, women showed statistically and clinically significantly greater flexion, adduction, and internal rotation during passive and 1-leg exercises whereas men showed statistically and clinically significantly greater flexion during the 2-leg hop or jump exercise.

LEVEL OF EVIDENCE

Level IV, meta-analysis and systematic review of Level II-IV studies.

Quantification of daily workload, energy expenditure, and sleep of US Marine recruits throughout a 10-week boot camp

BACKGROUND

During periods of high-volume vigorous exercise, United States Marine Corps recruits often experience musculoskeletal injuries. While the program of instruction (POI) for basic training is a defined training volume, the total workload of boot camp, including movements around the base, is unknown.

OBJECTIVE

The present study aimed to quantify the daily total workload, energy expenditure, and sleep during basic recruit training at Marine Corps Recruit Depot (MCRD) San Diego.

METHODS

Eighty-four male recruits from MCRD San Diego wore wrist wearable physiological monitors to capture their complete workload (mileage from steps), energy expenditure, and sleep throughout the 10-week boot camp.

RESULTS

Marine recruits traveled an average of 11.5±3.4 miles per day (M±SD), expended 4105±823 kcal per day, and slept an average of 5 : 48±1 : 06 hours and minutes per night. While the POI designates a total of 46.3 miles of running and hiking, the actual daily average miles yielded approximately 657.6±107.2 miles over the 10-week boot camp.

CONCLUSION

Recruit training requires high physical demand and time under tension due to the cumulative volume of movements around base in addition to the POI planned physical training.

Externally validated machine learning algorithm accurately predicts medial tibial stress syndrome in military trainees: a multicohort study

Objectives

Medial tibial stress syndrome (MTSS) is a common musculoskeletal injury in both sporting and military settings. No reliable treatments exist, and reoccurrence rates are high. Prevention of MTSS is critical to reducing operational burden. Therefore, this study aimed to build a decision-making model to predict the individual risk of MTSS within officer cadets and test the external validity of the model on a separate military population.

Design

Prospective cohort study.

Methods

This study collected a suite of key variables previously established for predicting MTSS. Data were obtained from 107 cadets (34 women and 73 men). A follow-up survey was conducted at 3 months to determine MTSS diagnoses. Six ensemble learning algorithms were deployed and trained five times on random stratified samples of 75% of the dataset. The resultant algorithms were tested on the remaining 25% of the dataset, with models then compared for accuracy. The most accurate new algorithm was tested on an unrelated data sample of 123 Australian Navy recruits to establish external validity of the model.

Results

Calibrated random forest modelling was the most accurate in identifying a diagnosis of MTSS; (area under curve (AUC)=98%, classification accuracy (CA)=96%). External validation on a sample of Navy recruits resulted in comparable accuracy; (AUC=95%, CA=94%). When the model was tested on the combined datasets, similar accuracy was achieved; (AUC=92%, CA=91%).

Conclusion

This model is highly accurate in predicting those who will develop MTSS. The model provides important preventive capacity which should be trialled as a risk management intervention.

The Identification and Comparison of Factors Affecting Musculoskeletal and Concussion Injury Disclosure

CONTEXT

Despite the increased risk of musculoskeletal (MSK) injury after a concussion, little is known about the determinants of such a risk. Moreover, the authors of previous reports of increased risk of MSK injury after a concussion have neglected to account for the high level of undisclosed concussions.

OBJECTIVE

To explore the association between the intention to disclose a possible concussion and the intention to disclose an MSK injury.

DESIGN

Cross-sectional study.

SETTING

Online survey.

PATIENTS OR OTHER PARTICIPANTS

One hundred seven National Collegiate Athletic Association Division I athletes (females = 79%, age = 19.4 ± 1.4 years).

MAIN OUTCOME MEASURE(S)

Online survey exploring determinants such as injury knowledge, attitudes, perceived social norms, and perceived behavioral control surrounding concussive and MSK injury disclosure.

RESULTS

A significant association between high intention to disclose a concussion and high intention to disclose an MSK injury (χ2 = 19.276, P < .001, Cramer V = 0.482) was observed. Spearman rank correlations suggested no correlation between concussion nondisclosure (25%) and MSK injury nondisclosure (52%). Multivariate binomial regressions indicated that perceived social norms were the strongest determinant (β = 1.365, P = .002) of high intention to disclose concussion, while attitudes toward MSK injury (β = 1.067, P = .005) and perceived social norms (β = 1.099, P = .013) were the strongest determinants of high intention to report MSK injury.

CONCLUSIONS

Individuals with high intention to report concussion symptoms also demonstrated high intention to report MSK injury. Strong positive associations were seen between known determinants of intention to disclose concussion and adapted versions of those same determinant domains in intention to disclose MSK injury. As those with high intention to disclose concussion also displayed high intention to disclose MSK injury, intention to disclose injuries generally may play a role in explaining the increase in MSK injury after a concussion.

Injuries and Health Issues Occurring During Offshore Transoceanic Sailing: A Survey of Recreational Sailors and Cruisers

INTRODUCTION

Most of the literature on sailing injuries is centered on competitive sailing, often involving a single regatta. The aims of this study were to provide a description of the types of injuries and illnesses sustained during amateur offshore cruising events, estimate their incidence, and investigate potential risk factors for injuries.

METHODS

We conducted a cross-sectional survey of self-reported sailing-related injuries and health issues during 4 different events organized by the World Cruising Club between 2014 and 2015. Prior to departure, sailors received an injury or health issue report form to complete during their sailing event. Questionnaires were then collected at the end of each event. Bivariable (Student's t tests and χ2 tests) and mutilvariable logistic regression were used to study the associations among injuries, health issues, and the characteristics of sailors or sailboats.

RESULTS

The incidence of injuries and health issues among the respondents was 1.08 and 1.01 per 10,000 nautical miles, respectively. Smaller boats (P<0.001) and crews with less experience with the current boat (P<0.001) were associated with reporting of more injuries. Most of the injuries were reported during favorable weather conditions. Health issues were more frequent on smaller boats and with women (P=0.008), who reported significantly more seasickness (P<0.001), anxiety (P=0.037), and skin rash/fungal infection (P=0.021).

CONCLUSIONS

Injuries and health issues are relatively common among amateur offshore recreational sailors, but severe injuries are rare. Smaller boats and having less experience in sailing with the current boat were associated with more injuries. Preventive strategies should include a sailing experience requirement on the boat being sailed for all crew members, increasing the minimum boat size requirement for sailing events, and mandatory first-aid training prior to a cruising event for all crew members.

Diagnostic Imaging for Distal Extremity Injuries in Direct Access Physical Therapy: An Observational Study

Background

Military physical therapists practicing direct-access routinely utilize diagnostic imaging and numerous published case reports demonstrate the ability of physical therapists to diagnose and appropriately disposition patients with foot/ankle and wrist/hand fractures. However, no larger cohort studies have explored the utilization of diagnostic imaging by physical therapists to detect fractures.

Hypothesis/Purpose

To describe the utilization of diagnostic imaging in foot/ankle and wrist/hand injuries by physical therapists in a direct-access sports physical therapy clinic.

Study Design

Retrospective cohort study.

Methods

The Agfa Impax Client 6 image viewing software (IMPAX) was searched from 2014 to 2018 for patients with diagnostic imaging ordered for foot/ankle and wrist/hand injuries. The Armed Forces Health Longitudinal Technology Application (AHLTA) electronic medical record was independently reviewed by the principal and co-investigator physical therapists. Data extracted were demographics and elements from the patient history and physical examination.

Results

In foot/ankle injuries, physical therapists diagnosed a fracture in 16% of the 177 cases and waited for an average of 3.9 days and 1.3 visits before ordering imaging. In wrist/hand injuries, physical therapists diagnosed a fracture in 24% of the 178 cases and waited for an average of 3.7 days and 1.2 visits before ordering imaging. The time to definitive care from the initial physical therapy evaluation was significantly different (p = 0.04) for foot/ankle fractures (0.6 days) compared to wrist/hand fractures (5.0 days). The Ottawa Ankle Rules demonstrated a negative likelihood ratio (-LR) of 0.11 (0.02, 0.72) and a positive likelihood ratio (+LR) of 1.99 (1.62, 2.44) for the diagnosis of foot/ankle fracture.

Conclusions

Physical therapists utilizing diagnostic imaging in a direct-access sports physical therapy clinic diagnosed fractures in similar proportions for foot/ankle and wrist/hand injuries and quickly dispositioned patients to definitive care for those fractures. The diagnostic accuracy of the Ottawa Ankle Rules was similar to previously reported values.

Level of Evidence

Level 3.

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

Background

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

Methods

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

Results

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

Conclusion

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

Health differences by entry stream among Canadian Armed Forces officer cadets

LAY SUMMARY

This study compared the baseline physical and mental health of officer candidates attending military college and officer training programs (i.e., non-direct-entry officer or non-DEO stream) with those of officers entering through a direct stream (direct-entry officer or DEO stream). Overall, DEO candidates had better health than non-DEO candidates. Female DEO and non-DEO candidates also reported more physical activity than male DEO and non-DEO candidates, and female non-DEO candidates had more symptoms of mental illness than male non-DEO candidates. A better understanding of these groups may lead to opportunities to customize health screening and supports depending on officer entry stream and sex; however, more research is needed to inform policy.

Epidemiology of Ankle Sprain in the Active-Duty Military Population

»

Ankle sprain is one of the most prevalent injuries within the military population, resulting in health-care costs, time away from active duty, and negative impacts on overall readiness.

»

Female service members appear to be more likely to sustain ankle sprains than male service members.

»

There is a need for additional research on prevention methods and rehabilitation programs for ankle sprains in the military population because the rate of ankle sprain in this population exceeds that in populations with less physically demanding lifestyles. Consequently, low-cost prevention strategies could yield substantial benefits.

Is Kinesio Taping Effective for Sport Performance and Ankle Function of Athletes with Chronic Ankle Instability (CAI)? A Systematic Review and Meta-Analysis

Background and Objectives: Ankle injuries are the most common type of injury in healthy active individuals. If not treated properly, recurrent sprains can lead to a condition of chronic ankle instability (CAI). The aim of the present review is to evaluate the effects of Kinesio Taping (or KT) on sports performances and ankle functions in athletes with CAI. Materials and Methods: This systematic review with meta-analysis was carried out following the criteria of the Prisma Statement system (registered on Open Science Framework, number: 10.17605/OSF.IO/D8QN5). For the selection of the studies, PubMed, Scopus and Web of Science were used as databases in which the following string was used: (“kinesiology tape” OR “tape” OR “taping” OR “elastic taping” OR “kinesio taping” OR “neuro taping”) AND (unstable OR instability) AND (ankle OR (ankle OR “ankle sprain” OR “injured ankle” OR “ankle injury”)). The Downs and Black Scale was used for the quality analysis. The outcomes considered were gait functions, ROM, muscle activation, postural sway, dynamic balance, lateral landing from a monopodalic drop and agility. Effect sizes (ESs) were synthesised as standardized mean differences between the control and intervention groups. Calculation of the 95% confidence interval (CI) for each ES was conducted according to Hedges and Olkin. Results: In total, 1448 articles were identified and 8 studies were included, with a total of 270 athletes. The application of the tape had a significant effect size on gait functions, ROM, muscle activation and postural sway. Conclusions: The meta-analysis showed a significant improvement in gait functions (step velocity, step and stride length and reduction in the base of support in dynamics), reduction in the joint ROM in inversion and eversion, decrease in the muscle activation of the long peroneus and decrease in the postural sway in movement in the mid-lateral direction. It is possible to conclude that KT provides a moderate stabilising effect on the ankles of the athletes of most popular contact sports with CAI.

Risk factors for injuries in female soldiers: a systematic review

Background

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

Methods

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

Results

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

Conclusion

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

A Longitudinal Study of Prevalence Ratios for Musculoskeletal Back Injury Among U.S. Navy and Marine Corps Personnel, 2009-2015

INTRODUCTION

Medical readiness to deploy is an increasingly important issue within the military. Musculoskeletal back pain is one of the most common medical problems that affects service members. This study demonstrates the associations between risk factors and the prevalence of musculoskeletal back pain among active duty sailors and Marines within the Department of the Navy (DoN).

MATERIALS AND METHODS

Utilizing the Military Health System Data Repository, we conducted a retrospective cross-sectional review of administrative healthcare claim data for all active duty DoN personnel with at least one medical encounter during fiscal years 2009-2015. For each fiscal year, we identified all claims with an ICD-9 code for back pain and calculated prevalence. We compared those with and without back pain across all variables (age, gender, rank, race, body mass index, tobacco use, occupation, and branch of service) using chi-square analysis. Unadjusted and adjusted log-binomial regressions were used to calculate prevalence ratios and examine associated risk factors for back pain.

RESULTS

The number of active duty subjects per fiscal year ranged from 424,460 to 437,053. The prevalence of back pain showed an upward trend, ranging from 9.99% in 2009 to 12.09% in 2015. Personnel aged 35 years and older had the strongest adjusted prevalence ration (APR) for back pain (APR 2.59; 95% CI, 2.53-2.66). There were also strong associations with obese body mass index (APR 1.76; 95% CI, 1.66-1.86), overweight body mass index (APR 1.29; 95% CI, 1.27-1.32), and tobacco use (APR 1.39; 95% CI, 1.36-1.42). Females were more likely to have back pain than males (APR 1.43; 95% CI, 1.40-1.47) and Marines more likely than sailors (APR 1.39; 95% CI, 1.36-1.42). The occupation with the highest prevalence ratio was healthcare (APR 1.34; 95% CI, 1.29-1.40) when compared to the reference group of combat specialists.

CONCLUSIONS

There was an increasing prevalence of back pain across the DoN from 2009 to 2015. Different occupational categories demonstrate different prevalence of back pain. Surprisingly, combat occupations and aviators were among the groups with the lowest prevalence. Lifestyle factors such as excess body weight and use of tobacco products are clearly associated with increased prevalence. These results could inform military leaders with regard to setting policies that could increase medical readiness.

Musculoskeletal Injuries Among Females in the Military: A Scoping Review

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Prevalence and Risk Factors for Musculoskeletal Back Injury Among U.S. Army Personnel

INTRODUCTION

Physical and medical readiness have emerged as a top priority in the army over the last decade. With this emphasis on deployment readiness, it is important to understand key risk factors attributed to common medical problems that arise in our soldiers, including low back pain. The purpose of this study is to elucidate demographic and lifestyle risk factors which would result in seeking medical care for musculoskeletal low back pain among active duty army personnel.

MATERIALS AND METHODS

A cross-sectional retrospective study investigating all active duty soldiers between October 1, 2016 and September 30, 2018 was performed using the existing Military Health System Data Repository to retrospectively review administrative claims data. Our study queried 39 unique International Classification of Disease codes, 10th Revision codes for low back pain to determine a positive case. We compared those with and without back pain across all variables using a chi-square analysis in SAS. Multivariate logistic analysis was performed to adjust for confounding within any single proposed risk factor and the six other proposed risk factors.

RESULTS

Six hundred fifty seven thousand and six thirty soldiers met inclusion criteria; 228,184 of whom had a medical encounter for low back pain (34.7%). All of the proposed risk factors included statistically significant unadjusted and adjusted odds ratios (ORs) with age conferring the greatest risk in soldiers aged 50-59 with an OR of 2.89 (2.73-3.05) compared to those aged 20-29. Obesity-adjusted OR was 1.77 (1.74-1.80) compared to those who were normal weight. Senior Enlisted status-adjusted OR was 1.34 (1.32-1.36). Females were 66% more likely to have low back pain compared to males with an OR of 1.66 (1.63-1.68).

CONCLUSION

Disease burden for low back pain tends to be high in the U.S. Army with 34.7% of service members experiencing low back pain. Older age, obesity, and being an enlisted, female service member are risk factors for these musculoskeletal injuries, which is in agreement with previously reported literature on the topic. To mitigate the burden of low back pain, policies and incentives to encourage healthy body mass index and lifestyle are needed. The results of this work inform future studies aimed at further delineating the risk factors found in this study.

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.

Worldwide epidemiology of foot and ankle injuries during military training: a systematic review

INTRODUCTION

Musculoskeletal foot and ankle injuries are commonly experienced by soldiers during military training. We performed a systematic review to assess epidemiological patterns of foot and ankle injuries occurring during military training.

METHODS

A review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search, done on 14 February 2019, resulted in 1603 reports on PubMed, 565 on Embase and 3 on the Cochrane Library. After reading the remaining full-text articles, we included 91 studies.

RESULTS

Among a population of 8 092 281 soldiers from 15 countries, 788 469 (9.74%) foot and ankle injuries were recorded. Among the 49 studies that reported on length of training, there were 36 770/295 040 (18.17%) injuries recorded among women and 248 660/1 501 672 (16.56%) injuries recorded among men over a pooled mean (±SD) training period of 4.51±2.34 months. Ankle injuries were roughly 7 times more common than foot injuries, and acute injuries were roughly 24 times more common than non-acute injuries. Our findings indicated that, during a 3-month training period, soldiers have a 3.14% chance of sustaining a foot and ankle injury. The incidence of foot or ankle injury during military parachutist training was 3.1 injuries per thousand jumps.

CONCLUSIONS

Our findings provide an overview of epidemiological patterns of foot and ankle injuries during military training. These data can be used to compare incidence rates of foot and ankle injuries due to acute or non-acute mechanisms during training. Cost-effective methods of preventing acute ankle injuries and non-acute foot injuries are needed to address this problem.

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.

Listening to music while running alters ground reaction forces: a study of acute exposure to varying speed and loudness levels in young women and men

PURPOSE

Music listening while running enhances physiological and psychological features, resulting in a more enjoyable experience. The possible influence of music on ground reaction forces (GRF) during running, however, is unknown. Considering the 'distracting' role of music on runner's attention, we hypothesized that music would cover foot impacts against the ground. This study verified such hypothesis by testing the effects of different music volumes while running at different velocities.

METHODS

Fifty fit volunteers (F:M = 22:8; 23 ± 2 years) performed 2-min running stints over 3 random conditions (80-dB, 85-dB music; 'no music'), at 3 velocities (8, 10, 12 km/h). Participants ran on a sensorized treadmill that recorded GRF during all experiments.

RESULTS

Listening to 85-dB music resulted in greater GRF at 8 (p = 0.0005) and 10 km/h (p = 0.04) but not 12 km/h (p = 0.35) and not with 80-dB volume. Gender-based analyses revealed significant Condition × gender interactions only for 85-dB music vs. 'no music'. Bonferroni-adjusted comparisons revealed significant music-induced increases in GRF only in men at 8 km/h (+ 4.1 kg/cm², p < 0.0005; women: + 0.8 kg/cm², p = 0.47) and 10 km/h (+ 3.3 kg/cm², p = 0.004; women: + 0.8 kg/cm², p = 0.51) but not at 12 km/h.

CONCLUSION

In active men, listening to loud music while running results in increased GRF, whereas no effect was observed in women. The lack of music effect in women may be related to structural factors, such as larger hip width-to-femoral length ratio, possibly resulting in different loading patterns. The present preliminary findings introduce high-volume music listening as a new potential risk factor for injury in young runners.

Foot and Ankle Related Sex-Specific Analysis Within High-Impact Journals

BACKGROUND

The impact of patient sex on the prevalence of foot and ankle injuries has been established. Reporting of differences on treatment outcomes is lacking. The purpose of this study was to identify trends in sex-specific outcomes across high-impact journals over a 5-year time period.

METHODS

Two independent investigators reviewed journal issues published during 2 calendar years (2011 and 2016) in the 5 highest-impact orthopedic foot and ankle/sports subspecialty journals (Foot & Ankle International [FAI], Foot and Ankle Surgery [FAS], American Journal of Sports Medicine [AJSM], Arthroscopy, and Knee Surgery, Sports Traumatology, Arthroscopy [KSSTA]). Studies were stratified into those that involved sex-specific analysis (SSA), where sex was a variable in a multifactorial statistical model, and those that only reported sex as a demographic characteristic or utilized sex-matched cohorts.

RESULTS

A total of 473 studies evaluating a total of 273 128 patients met criteria. An average of 43.9% (119 967 patients) of the population were female. Only 16.7% (79/473) of studies included sex as variable in a statistical model. Thirteen percent (25/193) and 19.3% (54/280) of studies reported SSA in 2011 and 2016, respectively. FAI was the only journal demonstrating a significant improvement of reporting SSA from 2011 to 2016 (P < .002). Thirty percent (24/79) of studies that performed SSA demonstrated significant differences between male and female outcomes.

CONCLUSION

Reporting of SSA in the orthopedic literature continued to be lacking. Only 16.7% of all articles evaluated in 2011 and 2016 performed SSA, with 30% of this subset reporting a statistically significant difference in outcomes.

LEVEL OF EVIDENCE

Level III, comparative study.

Surveyed Reasons for Not Seeking Medical Care Regarding Musculoskeletal Injury Symptoms in US Army Trainees

INTRODUCTION

Musculoskeletal injuries (MSKIs) pose a significant threat to military readiness and are difficult to monitor due to Soldiers' reluctance to seek medical treatment. There is high risk of developing MSKIs while going through initial entry training (IET), many of which go unreported. The purposes of this study were to identify the contributing factors that influence US Army trainees to not seek medical care for self-reported symptoms of musculoskeletal injury (SMSKI) and establish how those factors may differ by sex, training school, and installation site.

MATERIALS AND METHODS

Data were collected from 739 trainees (607 males, 132 females) completing IET at either Fort Benning, GA, Fort Sill, OK or Fort Leonard-Wood, MO, USA. Male trainees were in combat arms jobs while female trainees were from both combat arms and other physically demanding jobs. All surveys were completed within 5 weeks of graduation from Advanced Individual Training and One Station Unit Training. Trainees answered a series of questions about SMSKIs sustained during IET that lasted seven or more days. Using a Likert-type scale (1-strongly disagree through 5-strongly agree), trainees rated the influence that each of the following seven statements contributed to their decision not to seek medical care: "graduating on time," "avoiding negative perceptions associated with injuries," "avoiding profile," "inconvenience in seeing a provider," "self-managing the injury based on past experience," "severity of the injury," and "prior negative experiences seeking medical care in the military." Pearson's Chi-square test was used to assess significant relationships among SMSKI reporting across sex, training school and training installation.

RESULTS

Overall, SMSKI incidence was 36.1% and 58.3% among IET male and female trainees, respectively (40% overall). Nearly two-thirds (64%) of all trainees injured during IET had a SMSKI that they did not report to leadership or a medical provider. Across sex, female trainees were more likely to report SMSKIs than male trainees (p < 0.01), but there was no difference in SMSKI reporting rates by sex (p = 0.48). There was a difference in SMSKI rates by training school (p < 0.01), where infantry had higher SMSKI rates than field artillery (p < 0.01). There were no differences across training schools in how often trainees sought medical care (p = 0.58). The most common reasons selected for not reporting SMSKIs (i.e., not seeking medical care) included "I wanted to graduate on time" and "I wanted to avoid a profile." "I had prior negative experiences seeking medical care in the military" was consistently rated as the least important reason. Female trainees were more likely to not report SMSKIs in order "to avoid a profile" than male trainees (p < 0.05).

CONCLUSION

Over 64% of trainees' did not seek medical care for their SMSKI during IET. As early detection, better reporting and timely treatment may result in reductions in SMSKI severity, reduced IET attrition, and lower medical expenses, trainees should be encouraged to report SMSKIs for proper early stage treatment. These study findings could be used to assist military leadership to create a positive environment for reporting and seeking care for SMSKIs.

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.

Fit for fight - self-reported health in military women: a cross-sectional study

Background

Substantial research has found that women assess their health as poor relative to men, but the reasons for this are not fully understood. Military women are characterised by good health and the ability to work in an archetypically male culture. Thus, studies on the gender pattern of self-reported health in military personnel could generate hypotheses for future research on the possible associations between gender and health. However, such studies are rare and limited to a few countries. The aim of this study was to examine self-reported physical and mental health in Norwegian military women.

Methods

We compared responses on self-reported health of 1068 active duty military women in Norway to those of active duty military men (n = 8100). Further, we compared the military women to civilian women working in the Norwegian Armed Forces (n = 1081). Participants were stratified into three age groups: 20–29; 30–39; and 40–60 years. We used Pearson Chi-square tests, Students t-tests and regression models to assess differences between the groups.

Results

The military women in our study reported physical illness and injuries equal to those of military men, but more military women used pain relieving and psychotropic drugs. More military women aged 20–29 and 30–39 years reported mental health issues than military men of the same age. In the age group 30–39 years, twice as many military women assessed their health as poor compared to military men. In the age group 40–60 years, more military women than men reported musculoskeletal pain. Military women used less smokeless tobacco than military men, but there were few differences in alcohol consumption and smoking. Military women appeared to be more physically healthy than civilian women, but we found few differences in mental health between these two groups.

Conclusion

Most military women reported physical symptoms equal to those of military men, but there were differences between the genders in mental health and drug use. More favourable health compared to civilian women was most evident in the youngest age group and did not apply to mental health.

Injury Fear, Stigma, and Reporting in Professional Dancers

Background

Professional dance is a physically demanding career path with a high injury prevalence, yet an ingrained culture of hiding or pushing through injuries. Developing better knowledge surrounding the cultural beliefs and behaviors related to injury reporting is critical to understand their incidence and burden. Therefore, the aim of this study was to investigate injury fear and injury reporting behaviors in professional dancers in Australia.

Methods

This study utilized data collected in a cross-sectional survey of professional dancers in Australia. Descriptive analysis of injury fear and reporting stigma are presented with comparisons between subgroups (full-time versus part-time dancers; men versus women) conducted using two-sided Fisher's exact tests.

Results

A total of 146 professional dancers were included. Over half (63%) of the respondents reported that they fear sustaining a dance-related injury, that they believe there is still a stigma surrounding injuries in dance (62%), and that this stigma has led to a delay in reporting or seeking care for an injury (51%). A lower proportion of part-time than full-time dancers reported that they would usually tell someone within their dance employment about an injury (35.1% vs. 59.6%, p = 0.006).

Conclusion

Professional dancers are at risk of losing contracts or roles if they are injured, and therefore, it is common to dance through their occurrence. Many dancers, particularly those dancing part-time, are unwilling to tell their employers about their injuries. Action is required to improve this culture regarding injury reporting and help seeking for more effective injury understanding, prevention, and management in dance.

Testing a strength and conditioning program to prevent common manipulative technique training injuries in chiropractic students: a study protocol for a randomised controlled trial

Background

Spinal manipulation is the primary therapy utilised by chiropractors in the management of their patients. The skills required may feel foreign to chiropractic students as they need strength and endurance in movement patterns they may not have otherwise been exposed to. This may lead to injury while learning manipulative techniques. It is plausible to suggest that the implementation of a strength and conditioning program early in a practitioner’s career could reduce the incidence and progression of injuries. The study aims to test the effectiveness of a strength and conditioning program in reducing the risk of chiropractic students’ acquiring injuries while learning the skill of spinal manipulation.

Methods

This study will involve a prospective cohort of chiropractic students who are currently learning manual therapy at an undergraduate level. Participants will be eligible for inclusion if they are enrolled in 3rd or 4th-year chiropractic manual therapy units at Murdoch University chiropractic course. The intervention group will follow a 12-week strength and conditioning program comprised of preventative exercises that address each body region previously identified as being prone to injury. The control group will complete a 12-week walking program. The primary outcome is injury rate, measured via a short questionnaire. The secondary outcome will be strength, measured via submaximal strength tests.

Discussion

The prescribed exercises are aimed at improving the strength and endurance of those muscle groups involved in commonly taught manual therapy tasks. The resistance bands have been chosen as they are inexpensive, simple to implement for the purposes of the study, and acceptably safe. A video format was selected to allow ease of access for participants, provide a detailed description and a visual representation of the exercises to be performed. A questionnaire was designed as a means to assess the influence of the strength and conditioning program on injury rate and the impact this may have on the students’ ability to continue practicing. The International Physical Activity Questionnaire has been chosen to measure the participants level of activity before beginning the exercise program.

Conclusion

This research protocol will be the first large-scale study to investigate the effectiveness of a strength and conditioning program to reduce injuries within chiropractic students learning manual therapy.

Trial registration

Australia New Zealand Clinical Trials Registry (ACTRN12617001638325p).

Electronic supplementary material

The online version of this article (10.1186/s12998-018-0192-0) contains supplementary material, which is available to authorized users.

Validation of the Nasal Mucus Index, a novel measurement of acute respiratory infection severity

BACKGROUND

To assess the concurrent and predictive validity of the Nasal Mucus Index (NMI), a novel measurement of acute respiratory infection (ARI) severity.

OBJECTIVE

ARI, including the common cold and influenza, imposes a great burden on individuals and society. Previous research has attempted to assess the severity of ARI with self-reported and laboratory-based measurements. Self-reported measurements may introduce bias. Laboratory-based metrics are often expensive. Therefore, there is a need for non-self-reported, affordable, and validated ARI severity tests.

METHODS

Participants (N = 719) with an ARI episode underwent nasal lavage on days 1 and 3. The samples were visually assessed for the amount of mucus present in the sample and were given a subsequent NMI score. Collected samples were further assessed for interleukin (IL) 8 values (in pg/mL) and polymorphonuclear neutrophils (PMN) per high-power field. The participants rated episode severity and nasal symptoms daily by using the validated Wisconsin Upper Respiratory Symptom Survey-21 (WURSS-21). A subset of nasal symptoms was used as an additional comparator. NMI scores were compared with same-day IL-8 level, PMN count, and WURSS-21 scores for concurrent validation purposes by using the Spearman ρ as the index of correlation. NMI scores were correlated with overall episode severity measurements to assess predictive validity. Overall episode severity was measured as the WURSS-21 area under the curve, nasal symptoms area under the curve, and episode duration.

RESULTS

The NMI score correlated significantly with the same-day IL-8 level (ρ = 0.443, p < 0.001), PMN count (ρ = 0.498, p < 0.001), WURSS-21 score (ρ = 0.098, p = 0.004), and nasal symptom score (ρ = 0.162, p < 0.001). No significant predictive correlations were found.

CONCLUSION

Associations with inflammatory biomarkers and self-reported severity measurements provided evidence of concurrent validity for the novel NMI score. The NMI can be used in future research as a simple, inexpensive, non-self-reported indicator of ARI severity.

Underreporting of Musculoskeletal Injuries in the US Army: Findings From an Infantry Brigade Combat Team Survey Study

Background:

Musculoskeletal injury is a significant threat to readiness in the US Army. Current injury surveillance methods are constrained by accurate injury reporting. Input into electronic medical records or databases therefore may not accurately reflect injury incidence. The purpose of this study was to evaluate injury reporting among active-duty US Army soldiers to explore potential limitations of surveillance approaches.

Hypothesis:

A significant number of injuries go unreported to medical personnel.

Study Design:

Cross-sectional study.

Level of Evidence:

Level 4.

Methods:

Surveys were completed by soldiers assigned to an Army Infantry Brigade Combat Team. Survey questions inquired about injuries sustained in the previous 12 months, injury onset, and whether injuries were reported to a medical provider. Participants were asked to rank reasons for accurately reporting, underreporting, and/or exaggerating injuries. Chi-square analyses were used to compare differences among underreported injuries in terms of injury onset (gradual vs acute) and sex.

Results:

A total of 1388 soldiers reported 3202 injuries that had occurred in the previous 12-month period, including 1636 (51%) that were reported and 1566 (49%) that were identified as not reported to medical personnel. More than 49% of reported injuries were described as acute and 51% were described as chronic. Injury exaggeration was reported by 6% of soldiers. The most common reasons for not reporting injuries were fear that an injury might affect future career opportunities and avoidance of military “profiles” (mandated physical restrictions).

Conclusion:

Approximately half of musculoskeletal injuries in a Brigade Combat Team were not reported.

Clinical Relevance:

Unreported and untreated injuries can lead to reinjury, chronic pain, performance decrements, and increased costs associated with disability benefits. Additionally, unreported injuries can undermine injury surveillance efforts aimed at reducing the musculoskeletal injury problem in the military.

Soldier-relevant body borne loads increase knee joint contact force during a run-to-stop maneuver

The purpose of this study was to understand the effects of load carriage on human performance, specifically during a run-to-stop (RTS) task. Using OpenSim analysis tools, knee joint contact force, grounds reaction force, leg stiffness and lower extremity joint angles and moments were determined for nine male military personnel performing a RTS under three load configurations (light, ~6kg, medium, ~20kg, and heavy, ~40kg). Subject-based means for each biomechanical variable were submitted to repeated measures ANOVA to test the effects of load. During the RTS, body borne load significantly increased peak knee joint contact force by 1.2 BW (p<0.001) and peak vertical (p<0.001) and anterior-posterior (p=0.002) ground reaction forces by 0.6 BW and 0.3 BW, respectively. Body borne load also had a significant effect on hip (p=0.026) posture with the medium load and knee (p=0.046) posture with the heavy load. With the heavy load, participants exhibited a substantial, albeit non-significant increase in leg stiffness (p=0.073 and d=0.615). Increases in joint contact force exhibited during the RTS were primarily due to greater GRFs that impact the soldier with each incremental addition of body borne load. The stiff leg, extended knee and large braking force the soldiers exhibited with the heavy load suggests their injury risk may be greatest with that specific load configuration. Further work is needed to determine if the biomechanical profile exhibited with the heavy load configuration translates to unsafe shear forces at the knee joint and consequently, a higher likelihood of injury.

Nature and risk factors of injury hospitalization in young adults: A follow-up of 135,987 military conscripts

Aims: This study attempted to investigate the nature and risk factors of injury hospitalization among Finnish conscripts in 1998—2002. Methods: Altogether 135,987 military conscripts, including 2,044 (1.5%) women, were followed during their 6-to 12-month service in 1998—2002. Data on injury hospitalizations were obtained from the National Hospital Discharge Register. Outcome variables were injury hospitalization, multiple injury hospitalization, and hospitalization due to lower limb injury. Background variables consisted of conscripts' service and physical fitness data. Results: Injury hospitalization occurred among 6,059 (4.5%) conscripts, in 530 (0.4%) of them more than once. The total number of hospitalizations was 7,187, of which 50% were due to lower limb injuries. Most injuries (57%) were dislocations and sprains of joints and ligaments. The strongest risk factors for injury hospitalization in the multivariate logistic regression models were female sex (OR 2.3, 95% CI 1.9—2.7), and overweight (OR 1.4, 95% CI 1.2—1.7). These odds ratios increased when multiple injuries were investigated separately. Excellent aerobic fitness was a specific risk factor for lower limb injury (OR 1.3; 95% CI 1.1— 1.5). Conclusions: Women were markedly more likely than men to be hospitalized for injury. Moreover, overweight predicted an increased injury risk. Generalizable to the young adult population, the findings should be considered when identifying targets for injury prevention measures.

Association of Injury History and Incident Injury in Cadet Basic Military Training

PURPOSE

This study aimed to determine the association between injury history at enrollment and incident lower extremity (LE) injury during cadet basic training among first-year military cadets.

METHODS

Medically treated LE injuries during cadet basic training documented in the Defense Medical Surveillance System were ascertained in a prospective cohort study of three large US military academies from 2005 to 2008. Both acute injuries (International Classification of Disease, Ninth Revision, codes in the 800-900s, including fracture, dislocations, and sprains/strains) and injury-related musculoskeletal injuries (International Classification of Disease, Ninth Revision, codes in the 700s, including inflammation and pain, joint derangement, stress fracture, sprain/strain/rupture, and dislocation) were included. Risk ratio (RR) and 95% confidence interval (CI) were computed using multivariate log-binomial models stratified by gender.

RESULTS

During basic training, there were 1438 medically treated acute and 1719 musculoskeletal-related LE injuries in the 9811 cadets. The most frequent LE injuries were sprains/strains (73.6% of acute injuries) and inflammation and pain (89.6% of musculoskeletal-related injuries). The overall risk of incident LE injury was 23.2% (95% CI = 22.3%-24.0%). Cadets with a history of LE injury were at increased risk for incident LE injury. This association was identical in males (RR = 1.74, 95% CI = 1.55-1.94) and females (RR = 1.74, 95% CI = 1.52-1.99). In site-specific analyses, strong associations between injury history and incident injury were observed for hip, knee ligament, stress fracture, and ankle sprain. Injury risk was greater (P < 0.01) for females (39.1%) compared with males (18.0%). The elevated injury risk in females (RR = 2.19, 95% CI = 2.04-2.36) was independent of injury history (adjusted RR = 2.09, 95% CI = 1.95-2.24).

CONCLUSION

Injury history upon entry to the military is associated with the incidence of LE injuries sustained during cadet basic training. Prevention programs targeted at modifiable factors in cadets with a history of LE injury should be considered.

The incidence and prevalence of ankle sprain injury: a systematic review and meta-analysis of prospective epidemiological studies

BACKGROUND

Ankle sprain is one of the most common musculoskeletal injuries, yet a contemporary review and meta-analysis of prospective epidemiological studies investigating ankle sprain does not exist.

OBJECTIVE

Our aim is to provide an up-to-date account of the incidence rate and prevalence period of ankle sprain injury unlimited by timeframe or context activity.

METHODS

We conducted a systematic review and meta-analyses of English articles using relevant computerised databases. Search terms included Medical Search Headings for the ankle joint, injury and epidemiology. The following inclusion criteria were used: the study must report epidemiology findings of injuries sustained in an observed sample; the study must report ankle sprain injury with either incidence rate or prevalence period among the surveyed sample, or provide sufficient data from which these figures could be calculated; the study design must be prospective. Independent extraction of articles was performed by two authors using pre-determined data fields.

RESULTS

One-hundred and eighty-one prospective epidemiology studies from 144 separate papers were included. The average rating of all the included studies was 6.67/11, based on an adapted version of the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) guidelines for rating observational studies. 116 studies were considered high quality and 65 were considered low quality. The main findings of the meta-analysis demonstrated a higher incidence of ankle sprain in females compared with males (13.6 vs 6.94 per 1,000 exposures), in children compared with adolescents (2.85 vs 1.94 per 1,000 exposures) and adolescents compared with adults (1.94 vs 0.72 per 1,000 exposures). The sport category with the highest incidence of ankle sprain was indoor/court sports, with a cumulative incidence rate of 7 per 1,000 exposures or 1.37 per 1,000 athlete exposures and 4.9 per 1,000 h. Low-quality studies tended to underestimate the incidence of ankle sprain when compared with high-quality studies (0.54 vs 11.55 per 1,000 exposures). Ankle sprain prevalence period estimates were similar across sub-groups. Lateral ankle sprain was the most commonly observed type of ankle sprain.

CONCLUSIONS

Females were at a higher risk of sustaining an ankle sprain compared with males and children compared with adolescents and adults, with indoor and court sports the highest risk activity. Studies at a greater risk of bias were more likely to underestimate the risk of ankle sprain. Participants were at a significantly higher risk of sustaining a lateral ankle sprain compared with syndesmotic and medial ankle sprains.

Higher incidence of bone stress injuries with increasing female athlete triad-related risk factors: a prospective multisite study of exercising girls and women

BACKGROUND

Identifying the risk factors associated with a bone stress injury (BSI), including stress reactions and stress fractures, may aid in targeting those at increased risk and in formulating prevention guidelines for exercising girls and women.

PURPOSE

To evaluate the effect of single or combined risk factors as defined by the female athlete triad-a syndrome involving 3 interrelated spectrums consisting of energy availability, menstrual function, and bone mass-with the incidence of BSIs in a multicenter prospective sample of 4 cohorts of physically active girls and women.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

At baseline, participants' (N = 259; mean age, 18.1 ± 0.3 years) anthropometric characteristics, eating attitudes and behaviors, menstrual function, sports participation or exercise activity, and pathological weight control behaviors were assessed. Dual-energy x-ray absorptiometry (DXA) measured the bone mass of the whole body, total hip, femoral neck, lumbar spine, and body composition. Participants were followed prospectively for the occurrence of injuries; those injuries confirmed by a physician were recorded.

RESULTS

Twenty-eight participants (10.8%) incurred a BSI. Forty-six percent of those who had ≥12 h/wk of purposeful exercise, a bone mineral density (BMD) Z score <-1.0, and who exhibited 3 to 4 of the following: BMI <21.0 kg/m2, oligo- or amenorrhea, elevated dietary restraint, and/or participation in a leanness sport exercise/activity at baseline, incurred a BSI during the prospective study period. Single factors significantly (P < .05) associated with the development of a BSI included ≥12 h/wk of purposeful exercise (14.7%), BMI <21.0 kg/m2 (15.3%), and low bone mass (BMD Z score <-1.0; 21.0%). The strongest 2- and 3-variable combined risk factors were low BMD (Z score <-1.0) + ≥12 h/wk of exercise, with 29.7% incurring a BSI (odds ratio [OR], 5.1; 95% CI, 2.2-12.1), and ≥12 h/wk of exercise + leanness sport/activity + dietary restraint, with 46.2% incurring a BSI (OR, 8.7; 95% CI, 2.7-28.3).

CONCLUSION

In the sample, which included female adolescents and young adults participating in competitive or recreational exercise activities, the risk of BSIs increased from approximately 15% to 20% for significant single risk factors to 30% to 50% for significant combined female athlete triad-related risk factor variables. These data support the notion that the cumulative risk for BSIs increases as the number of Triad-related risk factors accumulates.

The outcome of a novel biomechanical therapy for patients suffering from anterior knee pain

BACKGROUND

This study was devised to examine the effect of a novel biomechanical therapy for patients suffering from anterior knee pain (AKP).

METHODS

A retrospective analysis of 48 patients suffering from AKP was performed. Patients underwent a gait evaluation, using an electronic walkway mat, and completed the SF-36 health survey and the WOMAC questionnaire at baseline and after 3 and 6months of therapy. A special biomechanical device was individually calibrated for each patient. AposTherapy is a functional, non-invasive rehabilitation therapy consisting of a biomechanical foot-worn device that is used during activities of daily living. Repeated measures analyses were performed to compare gait parameters and self-evaluation questionnaires between baseline, 3months and 6months.

RESULTS

Walking velocity significantly increased by 5.7cm/s, cadence increased by 1.6 steps/minute, and stride length increased by 3.4cm in relation to pretreatment testing (p<0.001 for all). End-point evaluation revealed additional improvement of these parameters; however these did not significantly differ from that of mid-treatment. Pain decreased by 36.6% and 49.2% following 13 and 26 weeks of treatment, respectively (P<0.01) and function improved by 25.2% and 41.7% following 13 and 26 weeks of treatment, respectively (P=0.01).

CONCLUSIONS

Based on the current study's results it may be concluded that this therapy might have a positive effect for patients with AKP.

Correlation of MRI grading of bone stress injuries with clinical risk factors and return to play: a 5-year prospective study in collegiate track and field athletes

BACKGROUND

Bone stress injuries are common in track and field athletes. Knowledge of risk factors and correlation of these to magnetic resonance imaging (MRI) grading could be helpful in determining recovery time.

PURPOSE

To examine the relationships between MRI grading of bone stress injuries with clinical risk factors and time to return to sport in collegiate track and field athletes.

STUDY DESIGN

Cohort study (prognosis); Level of evidence, 2.

METHODS

A total of 211 male and female collegiate track and field and cross-country athletes were followed prospectively through their competitive seasons. All athletes had preparticipation history, physical examination, and anthropometric measurements obtained annually. An additional questionnaire was completed regarding nutritional behaviors, menstrual patterns, and prior injuries, as well as a 3-day diet record. Dual-energy X-ray absorptiometry was performed at baseline and each year of participation in the study. Athletes with clinical evidence of bone stress injuries had plain radiographs. If radiograph findings were negative, MRI was performed. Bone stress injuries were evaluated by 2 independent radiologists utilizing an MRI grading system. The MRI grading and risk factors were evaluated to identify predictors of time to return to sport.

RESULTS

Thirty-four of the athletes (12 men, 22 women) sustained 61 bone stress injuries during the 5-year study period. The mean prospective assessment for participants was 2.7 years. In the multiple regression model, MRI grade and total-body bone mineral density (BMD) emerged as significant and independent predictors of time to return to sport. Specifically, the higher the MRI grade (P = .004) and lower the BMD (P = .030), the longer the recovery time. Location of the bone injury at predominantly trabecular sites of the femoral neck, pubic bone, and sacrum was also associated with a prolonged time to return to sport. Female athletes with oligomenorrhea and amenorrhea had bone stress injuries of higher MRI grades compared with eumenorrheic athletes (P = .009).

CONCLUSION

Higher MRI grade, lower BMD, and skeletal sites of predominant trabecular bone structures were associated with a delayed recovery of bone stress injuries in track and field athletes. Knowledge of these risk factors, as well as nutritional and menstrual factors, can be clinically useful in determining injury severity and time to return to sport.

Twenty years of work-related injury and illness among union carpenters in Washington State

BACKGROUND

Individuals who work in the construction industry are at high risk of occupational injury. Robust surveillance systems are needed to monitor the experiences of these workers over time.

METHODS

We updated important surveillance data for a unique occupational cohort of union construction workers to provide information on long-term trends in their reported work-related injuries and conditions. Combining administrative data sources, we identified a dynamic cohort of union carpenters who worked in Washington State from 1989 through 2008, their hours worked by month, and their workers' compensation claims. Incidence rates of reported work-related injuries and illnesses were examined. Poisson regression was used to assess risk by categories of age, gender, time in the union, and calendar time contrasting medical only and paid lost time claims.

RESULTS

Over the 20-year study period, 24,830 carpenters worked 192.4 million work hours. Work-related injuries resulting in medical care or paid lost time (PLT) from work occurred at a rate of 24.3 per 200,000 hr worked (95% CI: 23.5-25.0). Medical only claims declined 62% and PLT claims declined 77%; more substantive declines were seen for injuries resulting from being struck and falls to a lower level than from overexertion with lifting. Differences in risk based on union tenure and age diminished over time as well.

CONCLUSIONS

Significant declines in rates of reported work-related injuries and illnesses were observed over the 20-year period among these union carpenters. Greater declines were observed among workers with less union tenure and for claims resulting in PLT.

The relationship between foot motion and lumbopelvic-hip function: a review of the literature

Excessive pronation has been implicated in the development of numerous overuse injuries of the lower limb and is suggested to cause more proximal biomechanical dysfunction. Functional foot orthoses (FFO) are frequently prescribed for lower limb injury associated with excessive foot pronation and have been demonstrated to have efficacy with specific conditions. However, the mechanism of action of FFO is largely unknown. Research investigating the kinematic and kinetic changes associated with FFO use is inconclusive. Furthermore there is a growing body of evidence suggesting that changes to muscle activity patterns in response to FFO may be responsible for their therapeutic effect. Additionally, current research suggests dysfunction of musculature of the lumbopelvic-hip complex is involved in lower extremity functional changes and is related to the development some pathologies traditionally attributed to excessive foot pronation. Evidence of temporal coupling between the hip and the foot and changes in hip muscle activity associated with FFO use further suggest a relationship between proximal and distal lower limb function. The aim of this review is to discuss the association between foot and lumbopelvic-hip complex dysfunction and injury, assess the evidence for functional changes to lower limb and lumbopelvic-hip function with FFO use and finally to discuss the potential for changes to hip musculature activation with FFO use to influence distal mechanics and produce a therapeutic benefit.

The prevalence of patellofemoral joint disorders with surgical endpoint

The frequency of exercise-related injuries for physical activities and sports that have specifically lead to surgical intervention are rarely reported, especially regarding the patellofemoral articulation. Medical records from 1992 to 2005 of a multisite, urban-based hospital serving both large urban and rural populations were analyzed retrospectively. Injury data were presented by age, gender, and sport of choice. Significant (χ² = (6,519) = 31.097, p < .001) differences were found between age categories (adolescent, teenage, and adult) for the injuries leading to surgery. Significant gender (χ² (3,519) = 18.064, p < .001) differences were also found. This study presented a 13-year retrospective analysis of injuries to the patellofemoral joint leading to surgical endpoint, and found age and gender to significantly influence the frequency of injuries. Studies suggest that gender differences have not declined in response to the increasing number and experience of female athletes.

American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise

The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.

The role of patellar alignment and tracking in vivo: the potential mechanism of patellofemoral pain syndrome

PURPOSE AND METHOD

Lateral patellar malalignment and maltracking are commonly believed to be associated with patellofemoral pain. In the current review, a computerized and manual search of English-language articles was performed using multiple combinations of the following keywords: 'patellofemoral pain syndrome' or 'patellofemoral pain', and 'patellar alignment' or 'patellar tracking'. The role of patellar alignment and tracking in vivo is discussed via a review of papers regarding the differences in asymptomatic and symptomatic patella. An attempt is made to identify the potential mechanism of patellofemoral pain syndrome (PFPS).

CONCLUSION

Evidence suggests that symptomatic patella do not consistently demonstrate lateral malalignment or tracking in patellar tilt and translation. Abnormal patellar alignment and tracking may be potential risk factors that are associated with patellofemoral pain. Other contributing factors should be considered in dealing with patellofemoral pain syndrome. Further studies are required to determine what normal patella alignment and tracking is before going on to define how these are altered in subjects with patellofemoral pain. Furthermore, prospective studies are needed to identify the alteration of patellofemoral kinematics, if any, and whether these are the causative factor or the consequence of the patellofemoral pain syndrome, as well as to determine the risk of development of patellofemoral pain syndrome in individuals with and without abnormal patellar tracking.

Gender differences in the incidence and prevalence of patellofemoral pain syndrome

The purpose of this investigation was to determine the association between gender and the prevalence and incidence of patellofemoral pain syndrome (PFPS). One thousand five hundred and twenty-five participants from the United States Naval Academy (USNA) were followed for up to 2.5 years for the development of PFPS. Physicians and certified athletic trainers documented the cases of PFPS. PFPS was defined as retropatellar pain during at least two of the following activities: ascending/descending stairs, hopping/jogging, prolonged sitting, kneeling, and squatting, negative findings on examination of knee ligament, menisci, bursa, and synovial plica, and pain on palpation of either the patellar facets or femoral condyles. Poisson and logistic regressions were performed to determine the association between gender and the incidence and prevalence of PFPS, respectively. The incidence rate for PFPS was 22/1000 person-years. Females were 2.23 times (95% CI: 1.19, 4.20) more likely to develop PFPS compared with males. While not statistically significant, the prevalence of PFPS at study enrollment tended to be higher in females (15%) than in males (12%) (P=0.09). Females at the USNA are significantly more likely to develop PFPS than males. Additionally, at the time of admission to the academy, the prevalence of PFPS was not significantly different between genders.

Individuals with patellofemoral pain exhibit greater patellofemoral joint stress: a finite element analysis study

OBJECTIVE

To test the hypothesis that individuals with patellofemoral pain (PFP) exhibit greater patellofemoral joint stress profiles compared to persons who are pain-free.

METHODS

Ten females with PFP and ten gender, age, and activity-matched pain-free controls participated. Patella and femur stress profiles were quantified utilizing subject-specific finite element (FE) models of the patellofemoral joint at 15° and 45° of knee flexion. Input parameters for the FE model included: (1) joint geometry, (2) quadriceps muscle forces, and (3) weight-bearing patellofemoral joint kinematics. Using a nonlinear FE solver, quasi-static loading simulations were performed to quantify each subject's patellofemoral joint stress profile during a static squatting maneuver. The patella and femur peak and mean hydrostatic pressure as well as the peak and mean octahedral shear stress for the elements representing the chondro-osseous interface were quantified.

RESULTS

Compared to the pain-free controls, individuals with PFP consistently exhibited greater peak and mean hydrostatic pressure as well as peak and mean octahedral shear stress for the elements representing the patella and femur chondro-osseous interface across the two knee flexion angles tested (15° and 45°).

CONCLUSIONS

The combined finding of elevated hydrostatic pressure and octahedral shear stress across the two knee flexion angles supports the premise that PFP may be associated with elevated joint stress. Therefore, treatments aimed at decreasing patellofemoral joint stress may be indicated in this patient population.

Incidence of ankle sprains among active-duty members of the United States Armed Services from 1998 through 2006

CONTEXT

Ankle sprains have been reported as one of the most common injuries sustained by members of the US Armed Services. However, little is known about the incidence rate and injury patterns associated with ankle sprains in this population.

OBJECTIVE

To examine the incidence of ankle sprains among active-duty members of the US Armed Services from 1998 through 2006. A secondary objective was to describe the sex, age, and service-specific injury patterns in this young, physically active population.

DESIGN

Cohort study.

PATIENTS OR OTHER PARTICIPANTS

All active-duty service members from the day they enter military service until the day they leave military service and US Army Reserve and National Guard service members during periods of active duty and mobilization.

MAIN OUTCOME MEASURE(S)

Injury data were extracted from the Defense Medical Epidemiological Database from 1998 through 2006. All data for ankle sprains, coded according to the International Classification of Diseases (9th revision), were included. Cases were limited to those injuries reported as first occurrences. Incidence rates (IRs) were calculated per 1000 person-years by sex, age, and service. Incidence rate ratios (IRRs) and 95% confidence intervals (95% CIs) were used to assess the strength of association between the incidence of ankle sprain and the independent variables of sex, age, and service.

RESULTS

From 1998 through 2006, 423 581 service members sustained ankle sprains and 12 118 863 person-years at risk to injury were documented in this population. The incidence rate was 34.95 (95% CI = 34.85, 35.06) per 1000 person-years at risk. Females were 21% more likely (IRR = 1.21, 95% CI = 1.21, 1.23) to sustain an ankle sprain than males. Sex-specific IR varied by age and service. Differences in the rate of ankle sprains were also noted by age and service.

CONCLUSIONS

The incidence of ankle sprains among US service members was 5 times greater than that previously reported in civilian population studies. Sex, age, and branch of military service are important factors related to the incidence of ankle sprains in this population.

A proximal strengthening program improves pain, function, and biomechanics in women with patellofemoral pain syndrome

BACKGROUND

It is hypothesized that patients with patellofemoral pain syndrome (PFPS) have hip and core muscle weakness leading to dynamic malalignment of the lower extremity. Thus, hip strengthening is a common PFPS treatment approach.

PURPOSE

To determine changes in hip strength, core endurance, lower extremity biomechanics, and patient outcomes after proximally focused rehabilitation for PFPS patients.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Nineteen women (age, 22.68 ± 7.19 years; height, 1.64 ± 0.07 m; mass, 60.2 ± 7.35 kg) with PFPS participated in an 8-week program to strengthen the hip and core muscles and improve dynamic malalignment. Paired t tests were used to compare the dependent variables between prerehabilitation and postrehabilitation. The dependent variables were pain; functional ability; isometric hip abduction and external rotation strength; anterior, lateral, and posterior core endurance; joint range of motion (ROM; rearfoot eversion, knee abduction and internal rotation, and hip adduction and internal rotation); and peak internal joint moments (rearfoot inversion, knee abduction, and hip abduction and external rotation) during the stance phase of running.

RESULTS

Significant improvements in pain, functional ability, lateral core endurance, hip abduction, and hip external rotation strength were observed. There was also a significant reduction in the knee abduction moment during running, although there were no significant changes in joint ROM.

CONCLUSION

An 8-week rehabilitation program focusing on strengthening and improving neuromuscular control of the hip and core musculature produces positive patient outcomes, improves hip and core muscle strength, and reduces the knee abduction moment, which is associated with developing PFPS.