Sex Differences in Postinjury Health Profiles Among U.S. Military Personnel Following Deployment-Related Concussion.

Background: Women in the U.S. military are now authorized to serve in direct combat occupations. This may increase their risk of combat injuries, such as concussion, in future conflicts. Knowledge of sex differences in health profiles after concussion is paramount for military medical planning efforts. The purpose of this study was to assess sex-related differences in health profiles among U.S. military personnel following deployment-related concussion. Materials and Methods: We conducted a retrospective study of service members who sustained a concussion during combat deployment between 2004 and 2013. Postinjury diagnoses were abstracted from outpatient encounters in electronic health records for 24 months after concussion. We used hierarchical clustering to identify clusters, termed "health profiles," and logistic regression to determine whether sex predicted membership in the health profiles. Results: The study sample included 346 women and 4536 men with deployment-related concussion. Five postinjury health profiles were identified and classified as no morbidity, back pain, tinnitus/memory loss, posttraumatic stress disorder/postconcussion syndrome, and multimorbidity. Women relative to men had higher odds of membership in the back pain (odds ratio [OR] = 1.32; 95% confidence interval [CI] = 1.05-1.67) and multimorbidity profiles (OR = 1.44; 95% CI = 1.03-2.00) and lower odds than men in the tinnitus/memory loss profile (OR = 0.62; 95% CI = 0.42-0.91). Conclusions: Postinjury health profiles among U.S. service members differ by sex following deployment-related concussion, particularly with a higher burden of multimorbidity among women than men, which may require interdisciplinary care. Women also had higher odds of membership in the back pain profile and lower odds in the tinnitus/memory loss profile than men. To prepare for future military operations where women may have greater exposure to combat, continued research elucidating health-related sex differences after deployment-related concussion is imperative.

Burden and risk factors for Achilles tendinopathy in the military population from 2006 to 2015. A retrospective cohort study.

CONTEXT: Ankle-foot injuries are ubiquitous in the US military, with Achilles tendinopathy (AT) a common condition that affects function and health-related quality of life. OBJECTIVE: To evaluate the burden and associated factors of AT. DESIGN: Descriptive Epidemiology Study. SETTING: The Defense Medical Epidemiological Database was utilized to identify relevant healthcare encounters. PATIENTS OR OTHER PARTICIPANTS: All active duty and reserve military members who served between 2006 to 2015 (officers: n= 2 149 887; enlisted: n= 9 503 995). MAIN OUTCOME MEASURES: Multi-year prevalence of AT care episodes were calculated and compared by year, service branch, and military rank. Unadjusted and adjusted assessment of injury burden were calculated. RESULTS: Officers incurred 37,939 episodes at a prevalence of 17.65 per 1000 servicemembers (male officers: 18.20 per 1000 servicemembers; female officers: 14.80 per 1000 servicemembers). Among enlisted personnel, there were 116,122 episodes of AT that occurred in 12.22 per 1000 servicemembers (male enlisted: 12.07 per 1000 servicemembers; female enlisted: 13.22 per 1000 servicemembers). All officer specialties had significantly higher burden of AT episodes compared to the ground and naval gunfire officers (prevalence ratio [PR]: 1.04-1.43), except for aviation that demonstrated a significantly lower burden (PR: 0.65). Among enlisted occupations, maritime/naval specialties had lower burden of AT compared to infantry (PR: 0.82) and all other specialties, except for aviation, had significantly higher burden (PR: 1.07-1.71). There were multiple associated factors identified, to include sex, age, rank, military occupation, and service branch. CONCLUSION: AT was ubiquitous in the US military, with a progressive increase in prevalence during the study epoch. There were multiple associated factors identified, to include sex, age, rank, military occupation, and service branch. These findings highlight both the need for prophylactic interventions and identification of the populations with the greatest need.

Barriers and facilitators to implementation of musculoskeletal injury mitigation programmes for military service members around the world: a scoping review.

INTRODUCTION: Musculoskeletal injury (MSK-I) mitigation and prevention programmes (MSK-IMPPs) have been developed and implemented across militaries worldwide. Although programme efficacy is often reported, development and implementation details are often overlooked, limiting their scalability, sustainability and effectiveness. This scoping review aimed to identify the following in military populations: (1) barriers and facilitators to implementing and scaling MSK-IMPPs; (2) gaps in MSK-IMPP research and (3) future research priorities. METHODS: A scoping review assessed literature from inception to April 2022 that included studies on MSK-IMPP implementation and/or effectiveness in military populations. Barriers and facilitators to implementing these programmes were identified. RESULTS: From 132 articles, most were primary research studies (90; 68.2%); the remainder were review papers (42; 31.8%). Among primary studies, 3 (3.3%) investigated only women, 62 (69%) only men and 25 (27.8%) both. Barriers included limited resources, lack of stakeholder engagement, competing military priorities and equipment-related factors. Facilitators included strong stakeholder engagement, targeted programme design, involvement/proximity of MSK-I experts, providing MSK-I mitigation education, low burden on resources and emphasising end-user acceptability. Research gaps included variability in reported MSK-I outcomes and no consensus on relevant surveillance metrics and definitions. CONCLUSION: Despite a robust body of literature, there is a dearth of information about programme implementation; specifically, barriers or facilitators to success. Additionally, variability in outcomes and lack of consensus on MSK-I definitions may affect the development, implementation evaluation and comparison of MSK-IMPPs. There is a need for international consensus on definitions and optimal data reporting elements when conducting injury risk mitigation research in the military.

Effects of foot intensive rehabilitation (FIRE) on clinical outcomes for patients with chronic ankle instability: a randomized controlled trial protocol.

BACKGROUND: Lateral ankle sprains account for a large proportion of musculoskeletal injuries among civilians and military service members, with up to 40% of patients developing chronic ankle instability (CAI). Although foot function is compromised in patients with CAI, these impairments are not routinely addressed by current standard of care (SOC) rehabilitation protocols, potentially limiting their effectiveness. The purpose of this randomized controlled trial is to determine if a Foot Intensive REhabilitation (FIRE) protocol is more effective compared to SOC rehabilitation for patients with CAI. METHODS: This study will use a three-site, single-blind, randomized controlled trial design with data collected over four data collection points (baseline and post-intervention with 6-, 12-, and 24-month follow-ups) to assess variables related to recurrent injury, sensorimotor function, and self-reported function. A total of 150 CAI patients (50 per site) will be randomly assigned to one of two rehabilitation groups (FIRE or SOC). Rehabilitation will consist of a 6-week intervention composed of supervised and home exercises. Patients assigned to SOC will complete exercises focused on ankle strengthening, balance training, and range of motion, while patients assigned to FIRE will complete a modified SOC program along with additional exercises focused on intrinsic foot muscle activation, dynamic foot stability, and plantar cutaneous stimulation. DISCUSSION: The overall goal of this trial is to compare the effectiveness of a FIRE program versus a SOC program on near- and long-term functional outcomes in patients with CAI. We hypothesize the FIRE program will reduce the occurrence of future ankle sprains and ankle giving way episodes while creating clinically relevant improvements in sensorimotor function and self-reported disability beyond the SOC program alone. This study will also provide longitudinal outcome findings for both FIRE and SOC for up to two years. Enhancing the current SOC for CAI will improve the ability of rehabilitation to reduce subsequent ankle injuries, diminish CAI-related impairments, and improve patient-oriented measures of health, which are critical for the immediate and long-term health of civilians and service members with this condition. Trial Registration Clinicaltrials.gov Registry: NCT #NCT04493645 (7/29/20).

Deployment-related concussion and long-term health-related quality of life among US military personnel.

PURPOSE: To examine the relationship between deployment-related concussion and long-term health-related quality of life (HRQoL) among injured US military personnel. METHODS: The study sample included 810 service members with deployment-related injuries between 2008 and 2012 who responded to a web-based longitudinal health survey. Participants were categorized into three injury groups: concussion with loss of consciousness (LOC; n = 247), concussion without LOC (n = 317), or no concussion (n = 246). HRQoL was measured using the 36-Item Short Form Health Survey physical and mental component summary (PCS and MCS) scores. Current post-traumatic stress disorder (PTSD) and depression symptoms were examined. Multivariable linear regression models assessed the effects of concussion on PCS and MCS scores, while controlling for covariates. RESULTS: A lower PCS score was observed in participants with concussion with LOC (B = - 2.65, p = 0.003) compared with those with no history of concussion. Symptoms of PTSD (PCS: B = - 4.84, p < 0.001; MCS: B = - 10.53, p < 0.001) and depression (PCS: B = - 2.85, p < 0.001; MCS: B = - 10.24, p < 0.001) were the strongest statistically significant predictors of lower HRQoL. CONCLUSION: Concussion with LOC was significantly associated with lower HRQoL in the physical domain. These findings affirm that concussion management should integrate physical and psychological care to improve long-term HRQoL and warrant a more detailed examination of causal and mediating mechanisms. Future research should continue to incorporate patient-reported outcomes and long-term follow-up of military service members to further define the lifelong impact of deployment-related concussion.

Research Letter: Prevalence of Spine Injuries Among US Military Personnel With Combat-Related Concussion.

OBJECTIVE: To describe the prevalence of spine injuries among US service members with combat-related concussion. DESIGN AND PARTICIPANTS: A retrospective review of medical records for US service members injured during combat operations in Iraq and Afghanistan between 2002 and 2020. The study sample included 27 897 service members categorized into 3 groups: concussion with loss of consciousness (LOC, n = 4631), concussion non-LOC ( n = 5533), and non-concussion ( n = 17 333). MAIN MEASURES: Spine injuries were identified by International Classification of Diseases, Ninth Revision, Clinical Modification ( ICD-9-CM ) codes and classified by body region and nature of injury using the Barell injury diagnosis matrix. Differences in prevalence of spine injuries by concussion group were evaluated using χ 2 tests. RESULTS: Spine injuries were most prevalent among service members with concussion LOC (31.1%), followed by concussion non-LOC (18.3%), and non-concussion (10.0%, P < .001). Sprains and strains were the most prevalent spine injury category, with injuries to the cervical, thoracic, and lumbar regions significantly more prevalent in the concussion groups ( P values < .001), particularly individuals with LOC compared with non-concussion. CONCLUSION: The US military personnel with combat-related concussion, especially individuals with LOC, may also have spine injuries. Routine assessment for spine injury is recommended during concussion screening because this may impact clinical management and rehabilitation.

Consistency and applicability of return to function guidelines in tactical-athletes with exertional heat illness. A systematic review.

OBJECTIVE: To assess the consistency of return to sport and occupation recommendations following EHI provided in published clinical practice guidelines, consensus statements, position statements, and practice alerts. The agreement between medical policies governing the return to duty following EHI between the branches of the United States Armed Forces and published recommendations was assessed. METHODS: Ovid MEDLINE, Web of Science, and CINAHL databases were searched for clinical practice guidelines and position statements published at any time that guided return to activity in individuals with EHI. Methodological quality was assessed, and the specific recommendations for clinical management were extracted. Consistency of recommendations was evaluated. Agreement between published guidelines and the policies governing return to activity in military tactical athletes with heat injury were also evaluated. RESULTS: Guidelines developed by two civilian sports medicine societies in the United States detailing recommendations for return to function following EHI were identified. There was consistency between guidelines regarding recommendations that addressed abstinence from activity; medical follow-up; graded resumption of activity; and return to function. Pertaining military policy, contemporary regulations published in recent years reflected the recommendations provided in the professional guidelines. The greatest incongruence was noted in older military policies. CONCLUSIONS: This systematic review highlights the need for consistent recommendations across all branches of the military and medical specialties pertaining to returning servicemembers to duty after EHI .

Participant-Level Analysis of the Effects of Interventions on Patient-Reported Outcomes in Patients With Chronic Ankle Instability.

CONTEXT: Intervention studies for chronic ankle instability (CAI) often focus on improving physical impairments of the ankle complex. However, using an impairments-focused approach may miss psychological factors that may mediate function and recovery. Patient-reported outcome (PRO) measures can be used to assess several dimensions of the health-related quality of life (HRQoL) and deliver enhanced patient-centered care. Therefore, the purpose of this investigation was to evaluate group-level improvements in HRQoL and treatment response rates following various interventions in patients with CAI. DESIGN: Cross-sectional. METHODS: Data from 7 previous studies were pooled by the chronic ankle instability outcomes network for participant-level analysis, resulting in 136 patients with CAI. Several interventions were assessed including balance training, gait biofeedback, joint mobilizations, stretching, and strengthening, with treatment volume ranging from 1 to 4 weeks. Outcome measures were PROs that assessed ankle-specific function (Foot and Ankle Ability Measure), injury-related fear (Tampa Scale of Kinesiophobia and Fear Avoidance Belief Questionnaire), and global well-being (Disablement in the Physically Active); the PROs assessed varied between studies. Preintervention to postintervention changes were evaluated using separate Wilcoxon signed-rank tests and effect sizes, and a responder analysis was conducted for each PRO. RESULTS: Significant, moderate to large improvements were observed in PROs that assessed ankle-specific function, injury-related fear, and global well-being following intervention (P < .001). Responder rates ranged from 39.0% to 53.3%, 12.8% to 51.4%, and 37.8% for ankle specific function, injury-related fear, and global well-being, respectively. CONCLUSIONS: Various interventions can lead to positive improvements in HRQoL in patients with CAI. Treatment response rates at improving HRQoL are similar to response rates at improving impairments such as balance, further reinforcing the need for individualized treatment approaches when treating a patient with CAI.

The Influence of Therapeutic Exercise after Ankle Sprain on the Incidence of Subsequent Knee, Hip, and Lumbar Spine Injury.

PURPOSE: This study aimed to investigate the burden of knee, hip, and lumbar spine disorders occurring in the year after an ankle sprain and the influence therapeutic exercise (TE) has on this burden. METHODS: A total of 33,361 individuals diagnosed with ankle sprain in the Military Health System between 2010 and 2011 were followed for 1 yr. The prevalence of knee, hip, and lumbar care-seeking injuries sustained after sprain was identified. Relationships between demographic groups, ankle sprain type, and use of TE with rate of proximal injuries were evaluated using Cox proportional hazard models to determine hazard rate effect modification by attribute. The observed effect of TE for ankle sprain on rate of injury to proximal joints was evaluated using Kaplan-Meier survival analyses. RESULTS: Of the total cohort, 20.5% ( n = 6848) of patients sustained a proximal injury. Specifically, 10.1% of the cohort sustained a knee ( n = 3356), 2.9% a hip ( n = 973), and 10.3% a lumbar injury ( n = 3452). Less than half of the cohort received TE after initial sprain. Patients that did were less likely to have subsequent knee (HR = 0.87, 95% confidence interval [CI] = 0.80-0.94), hip (HR = 0.68, 95% CI = 0.58-0.79), or lumbar (HR = 0.82, 95% CI = 0.76-0.89) injuries. CONCLUSIONS: One in five individuals that sought care for an ankle sprain experienced a proximal joint injury in the following year. TE for the management of the initial ankle sprain reduced the likelihood of proximal injury diagnosis and should be considered in treatment plans for return to work and sport protocols after ankle sprains.

Macrotraumatic Fractures of the Multisegmented Ankle-Foot Complex in Military Tactical Athletes: A Cohort Study.

BACKGROUND: Ankle-foot injuries are common in military personnel and substantially degrade function and force readiness. The purpose of this retrospective cohort study was to assess the incidence and contributing factors of traumatic ankle-foot fractures in the US military. METHODS: A population-based study of all service members in the US military was performed assessing the factors of sex, occupation, service branch, rank, and year on segmental tibia-fibula, rearfoot, and forefoot fracture incidence between 2006 and 2015. The Defense Medical Epidemiology Database was queried for the number of individuals with fractures of the tibia-fibula, rearfoot, and forefoot using International Classification of Diseases, Ninth Revision, Clinical Modification on the initial medical encounter. Unadjusted relative risk (RR) calculations were performed assessing sex and occupation. A negative binomial regression assessed the adjusted factors of sex, branch, rank, and year. RESULTS: During this study, 95,540 enlisted service members (8.4 per 1,000 person-years) and 13,318 military officers (5.8 per 1,000 person-years) were diagnosed with ankle-foot fractures. In the adjusted analysis, sex was found to only be a significant factor in forefoot fractures (RR, 1.54), with female service members having a significantly higher risk. There were no significant sex-related differences observed in tibia-fibula or rearfoot fractures. US Navy and Air Force personnel had significantly lower risk of tibia-fibula fractures (RR range, 0.76-0.84) compared with the US Army. Forefoot fracture risk was significantly higher in the US Marine Corps (RR, 1.47) compared with the US Army. Officers had consistently lower risk for fractures in each segment (RR range, 0.68-0.77) compared with enlisted personnel. Enlisted engineers, aviation, and artillery/gunnery compared to infantry, and ground/naval gunfire officers had the greatest relative risk compared all other officer fields (RR range, 1.11-3.67). CONCLUSIONS: Sex, occupation, branch, and rank were salient factors for macrotraumatic ankle-foot fractures. These findings can be used to inform and increase precision in medical planning and in the targeted development of preventive interventions.

Factors Associated With Neuromusculoskeletal Injury and Disability in Navy and Marine Corps Personnel.

INTRODUCTION: Neuromusculoskeletal injuries (NMSKI) are very common in the military, which contribute to short- and long-term disability. MATERIALS AND METHODS: Population-level NMSKI, limited duty (LIMDU), and long-term disability episode counts in the U.S. Navy (USN) and U.S. Marine Corps (USMC) from December 2016 to August 2021 were extracted from the Musculoskeletal Naval Epidemiological Surveillance Tool. The incidence of NMSKI, LIMDU, and long-term disability was calculated. A hurdle negative binomial regression evaluated the association of body region, sex, age, rank, age by rank, and service branch on NMSKI, LIMDU, and long-term disability incidence. RESULTS: From December 2016 to August 2021, there were 2,004,196 NMSKI episodes (USN: 3,285/1,000 Sailors; USMC: 4,418/1,000 Marines), 16,791 LIMDU episodes (USN: 32/1,000 Sailors; USMC: 29/1,000 Marines), and 2,783 long-term disability episodes (USN: 5/1,000 Sailors; USMC: 5/1,000 Marines). There was a large-magnitude protective effect on NMSKI during the pandemic (relative risk, USN: 0.70; USMC: 0.75). Low back and ankle-foot were the most common, primarily affecting female personnel, aged 25-44 years, senior enlisted, in the USMC. Shoulder, arm, pelvis-hip, and knee conditions had the greatest rates of disability, with female sex, enlisted ranks, aged 18-24 years, and service in the USMC having the most salient risk factors. CONCLUSION: Body region, sex, age, rank, and branch were the salient factors for NMSKI. The significant protective effect during the pandemic was likely a function of reduced physical exposure and limited access to nonurgent care. Geographically accessible specialized care, aligned with communities with the greatest risk, is needed for timely NMSKI prevention, assessment, and treatment.

The Neuromusculoskeletal Epidemiological Outcome (NEO) matrix: An innovative injury classification based on anatomical location and primary tissue type.

INTRODUCTION: The purpose of this paper is to propose the Neuromusculoskeletal Epidemiological Outcome (NEO) Matrix, an injury classification based on anatomical location and primary tissue type to classify NMSKI of the trunk and extremities in orthopaedic and sports medicine epidemiological research. MATERIALS AND METHODS: In the proposed NEO matrix, NMSKI diagnosis (International Classification of Disease) codes are classified by the anatomical complex affected. These regional anatomical complexes are frequently employed in orthopaedic and sports medicine disciplines in biomechanical and clinical research. The complexes are arranged from distal to proximal in the lower extremity, inferior to superior in the trunk and head, and proximal to distal in the upper extremity. Injuries are characterized by the primary tissue type affected (Osseous; Articular; Musculotendinous; Neural; Non-specific) based on classified using International Classification of Disease codes. DISCUSSION: The expected patterns of impairment and healing rates of bone, cartilage, ligaments, muscles, tendons, and neural structures vary considerably by the tissue type based on the differences in function, perfusion, and metabolic physiology. Using knowledge of the function of the tissues, expected minimum healing times, and expected sequelae of residual body system impairments, an estimation of morbidity and expected recovery times can be made. While heterogeneity is certainly expected due to varying pathomechanics involved and intrinsic and environmental factors, the NEO matrix classifies the ICD diagnosis codes in framework that qualifies the expected patterns of impairment based on the body system type. CONCLUSION: The NEO matrix provides an alternative approach for characterizing NMSKI in epidemiological research.

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.

Muscle Engagement Monitoring Using Self-Adhesive Elastic Nanocomposite Fabrics.

Insight into, and measurements of, muscle contraction during movement may help improve the assessment of muscle function, quantification of athletic performance, and understanding of muscle behavior, prior to and during rehabilitation following neuromusculoskeletal injury. A self-adhesive, elastic fabric, nanocomposite, skin-strain sensor was developed and validated for human movement monitoring. We hypothesized that skin-strain measurements from these wearables would reveal different degrees of muscle engagement during functional movements. To test this hypothesis, the strain sensing properties of the elastic fabric sensors, especially their linearity, stability, repeatability, and sensitivity, were first verified using load frame tests. Human subject tests conducted in parallel with optical motion capture confirmed that they can reliably measure tensile and compressive skin-strains across the calf and tibialis anterior. Then, a pilot study was conducted to assess the correlation of skin-strain measurements with surface electromyography (sEMG) signals. Subjects did biceps curls with different weights, and the responses of the elastic fabric sensors worn over the biceps brachii and flexor carpi radialis (i.e., forearm) were well-correlated with sEMG muscle engagement measures. These nanocomposite fabric sensors were validated for monitoring muscle engagement during functional activities and did not suffer from the motion artifacts typically observed when using sEMGs in free-living community settings.

Effects of Midfoot Joint Mobilization on Perceived Ankle-Foot Function in Chronic Ankle Instability: A Crossover Clinical Trial.

CONTEXT: To investigate the effects of midfoot joint mobilization and a 1-week home exercise program, compared with a sham intervention, and home exercise program on pain, patient-reported outcomes, ankle-foot joint mobility, and neuromotor function in young adults with chronic ankle instability. DESIGN: Crossover clinical trial. METHODS: Twenty participants with chronic ankle instability were instructed in a stretching, strengthening, and balance home exercise program and were randomized a priori to receive either midfoot joint mobilizations (forefoot supination, cuboid glide, and plantar first tarsometatarsal) or a sham laying of hands on the initial visit. Changes in foot morphology, joint mobility, strength, dynamic balance, and patient-reported outcomes assessing pain, physical, and psychological function were assessed pre to post treatment and 1 week following post treatment. Participants crossed over to receive the alternate treatment and were assessed pre to post treatment and 1 week following. Linear modeling was used to assess changes in outcomes. RESULTS: Participants demonstrated significantly greater perceived improvement immediately following midfoot mobilization in the single assessment numeric evaluation (sham: 5.0% [10.2%]; mobilization: 43.9% [26.2%]; ß: 6.8; P < .001; adj R2: .17; Hedge g: 2.09), and global rating of change (sham: -0.1 [1.1]; mobilization: 1.1 [3.0]; ß: 1.8; P = .01; adj R2: .12; Hedge g: 0.54), and greater improved 1-week outcomes in rearfoot inversion mobility (sham: 4.4° [8.4°]; mobilization: -1.6° [6.1°]; ß: -6.37; P = .01; adj R2: .19; Hedge g: 0.81), plantar flexion mobility (sham: 2.7° [6.4°]; mobilization: -1.7° [4.3°]; ß: -4.36; P = .02; adj R2: .07; Hedge g: 0.80), and posteromedial dynamic balance (sham: 2.4% [5.9%]; mobilization: 6.0% [5.4%]; ß: 3.88; P = .04; adj R2: .10; Hedge g: 0.59) compared to the sham intervention. CONCLUSION: Greater perceived improvement and physical signs were observed following midfoot joint mobilization.

Uneven Treadmill Training for Rehabilitation of Lateral Ankle Sprains and Chronic Ankle Instability: Protocol for a Pragmatic Randomized Controlled Trial.

BACKGROUND: Lateral ankle sprains (LASs) are common injuries among military service members. Approximately 40% of individuals with an LAS progress to develop chronic ankle instability (CAI), a condition that results in substantial mechanical and neurophysiological impairment and activity limitation. Since proprioceptive and balance training improve functional outcomes and prevent secondary injury following LAS, they are recommended in clinical practice. Uneven treadmills are an innovative modality that challenge the sensorimotor system while performing an ecologically valid task simulating environments frequently encountered by service members with LAS and CAI. OBJECTIVE: The aim of this study is to evaluate whether the inclusion of uneven treadmill training in standard rehabilitation can improve clinical, functional, biomechanical, and patient-reported outcomes compared with the standard of care alone in service members with LAS and CAI. The prophylactic effects of treatment on secondary injury and identification of any contributing or mediating factors that influence outcomes following treatment will also be evaluated. We hypothesize that service members receiving uneven treadmill training will demonstrate greater improvements in clinical and instrumented measures of impairment, patient-reported function, and lower risk of injury recurrence than the control group immediately post and 18 months following treatment. METHODS: A multisite, parallel randomized clinical trial will be performed among service members aged 18-49 years being treated for LAS and CAI in military treatment facilities in the United States. Participants randomly assigned and allocated to receive the experimental intervention will be provided up to 12 sessions of training on an uneven terrain treadmill over a 6-week treatment course to supplement standard rehabilitation care. Treatment intensity of the rehabilitation exercises and treadmill training will be progressed on the basis of patient-perceived intensity and treatment responses. Outcome measures will include patient-reported outcomes, functional assessments, performance measures, and biomechanical measures. Investigators collecting outcome measures will be blinded to treatment allocation. Reinjury rates and patient-reported outcomes of function will be tracked over 18 months following treatment. RESULTS: The project was funded in September 2020. Patient recruitment began in November 2021, with 3 participants enrolled as of February 2022. Dissemination of the main study findings is anticipated in 2024. CONCLUSIONS: This study will assess the impact of an innovative uneven-terrain treadmill on treatment outcomes in the rehabilitation of service members with LAS and CAI. The results of this study will be used to inform rehabilitation practices and to potentially improve functional outcomes and secondary prevention in this patient population. TRIAL REGISTRATION: ClinicalTrials.gov NCT04999904; https://clinicaltrials.gov/ct2/show/NCT04999904?term=NCT04999904. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/38442.

Association of Ankle Sprain Frequency With Body Mass and Self-Reported Function: A Pooled Multisite Analysis.

CONTEXT: Ankle sprains result in pain and disability. While factors such as body mass and prior injury contribute to subsequent injury, the association of the number of ankle sprains on body anthropometrics and self-reported function are unclear in this population. Therefore, the purpose of this investigation was to assess differences in anthropometric measurements and self-reported function between the number of ankle sprains utilizing a large, pooled data set. DESIGN: Cross-sectional. METHODS: Data were pooled from 14 studies (total N = 412) collected by the Chronic Ankle Instability Outcomes Network. Participants were categorized by the number of self-reported sprains. Anthropometric data and self-reported function were compared between those who reported a single versus >1 ankle sprain as well as among groups of those who had 1, 2, 3, 4, and ≥5 ankle sprains, respectively. RESULTS: Those who had >1 ankle sprain had higher mass (P = .001, d = 0.33) and body mass index (P = .002, d = 0.32) and lower Foot and Ankle Ability Measure-Activities of Daily Living (P < .001, r = .22), Foot and Ankle Ability Measure-Sport (P < .001, r = .33), and Cumberland Ankle Instability Tool (P < .001, r = .34) scores compared to the single ankle sprain group. Those who had a single ankle sprain weighed less than those who reported ≥5 sprains (P = .008, d = 0.42) and had a lower body mass index than those who reported 2 sprains (P = .031, d = 0.45). CONCLUSIONS: Some individuals with a history of multiple ankle sprains had higher body mass and self-reported disability compared to those with a single sprain, factors that are likely interrelated. Due to the potential for long-term health concerns associated with ankle sprains, clinicians should incorporate patient education and interventions that promote physical activity, healthy dietary intake, and optimize function as part of comprehensive patient-centered care.

Sex Differences in the Incidence and Risk of Ankle-Foot Complex Stress Fractures Among U.S. Military Personnel.

Background: The objective of this study was to evaluate sex differences in the incidence and risk of ankle-foot complex (AFC) stress fractures among U.S. military personnel, which could assist in developing management strategies as females assume a greater role in U.S. military operations. Materials and Methods: The Defense Medical Epidemiology Database was used to identify all diagnosed AFC stress fractures in military personnel from 2006 to 2015. Cumulative incidence of AFC stress fractures was calculated and compared by year, service branch, and military rank. Sex differences in the risk of AFC stress fractures by occupation were examined, and integrated (i.e., male and female) occupations were compared with nonintegrated (i.e., male only) occupations. Results: A total of 43,990 AFC stress fractures were identified. The overall incidence rate was 2.76 per 1,000 person-years (p-y) for males and 5.78 per 1,000 p-y for females. Females consistently had higher incidence of AFC stress fractures across all subgroups, particularly among enlisted personnel. Female enlisted service members had the highest risk of AFC stress fractures in aviation (relative risk [RR] = 5.74; 95% confidence interval [CI]: 4.80-6.87) and artillery/gunnery (RR = 5.15; 95% CI: 4.62-5.75) occupations. Females in integrated occupations had significantly higher rates of AFC stress fractures than males in both integrated and nonintegrated occupations (i.e., special forces, infantry, and mechanized/armor). Conclusions: Females in the U.S. military have a higher risk of AFC stress fractures than males. As integration of females into previously sex-restricted occupations continues, focused prevention efforts may be needed to reduce injury burden and maximize medical readiness.