Risk Of Musculoskeletal Injury Research Articles

Post-performance Recovery And Musculoskeletal Injury Risk In Collegiate Women’S Hockey Players

Post-performance Recovery And Musculoskeletal Injury Risk In Collegiate Women’S Hockey Players

Comparative Analysis of Kinetic Responses and Injury Risk During Landing from 45 cm Height: A Study of Barefoot vs. Sports Shoes Conditions

Jumping and landing biomechanics are closely related to the risk of acute injury due to prolonged exposure to high-ground reaction forces in basketball-like sports, which can lead to lower-limb musculoskeletal injuries in the hip, knee, and ankle. Footwear greatly impacts jumping mechanics, but going barefoot provides a unique perspective on how the human body interacts with the ground. This study aims to find out the kinetic responses during drop landing from 45 cm height with and without sports shoe conditions. Twenty-five healthy young adults were volunteers for this study. Kinetic parameters were recorded and processed by using Quattro Jump force plat and Mars Quarter performance analysis software. Data were presented as mean ± SD values and statistical analysis was performed using statistical software package SPSS-26. The drop landing data of with and without shoe shows scattered parameters with maximum forces of 4706.12N and 5393.04N at 45 cm height, indicating a 66% and 75% risk of metatarsal injury. The stabilization force was 632.64N and 623.64N at 45 cm, reached at 0.58s and 0.66s respectively. Time from Max Force to MFBS Regression analysis indicated a low R-squared value and a random fit plot. In barefoot (without shoe) conditions, the initial contact force, and maximum force were 85.71% and 13.60% higher (250N and 5393.04N respectively) compared to landing with shoes (100N and 4706.12N). However, the stabilization force was higher (632.64N) when landing with shoes compared to landing barefoot (623.64N). As a result, the risk of musculoskeletal injuries and joint stress was higher when landing barefoot due to the higher initial contact force and maximum force. On the other hand, landing with shoes enhances balance and stability due to the higher stabilization force.

Using accelerometers to identify a high risk of catastrophic musculoskeletal injury in three racing Thoroughbreds.

To describe the process whereby the screening of racing Thoroughbreds with accelerometer-based inertial measurement unit (IMU) sensors followed by clinical evaluation and advanced imaging identified potentially catastrophic musculoskeletal injuries in 3 horses. 3 Thoroughbred racehorses. All cases demonstrated an abnormal stride pattern either during racing (cases 1 and 2) or while breezing (case 3) and were identified as being at very high risk of catastrophic musculoskeletal injury by an algorithm derived from IMU sensor files from > 20,000 horses' race starts. Veterinary examination and 18F-sodium fluoride (18F-NaF) positron emission tomography were performed within 10 days of the respective race or breeze in each of the cases. The intensity and location of the 18F-NaF uptake in the condyles of the third metacarpal bone in cases 1 and 2 identified them as at potential increased risk of condylar fracture. The pattern and intensity of the 18F-NaF uptake in case 3 indicated that the third carpal bone was likely responsible for the horse's lameness, with an impending slab fracture subsequently identified on radiographs. Following periods of convalescence, cases 1 and 2 returned to racing and were identified by the sensor system as no longer being at high risk of catastrophic musculoskeletal injury. Case 3 returned to training but has yet to return to racing. When worn by Thoroughbreds while racing or breezing, these IMU sensors can identify horses at high risk of catastrophic musculoskeletal injury, allowing for veterinary intervention and the potential avoidance of such injuries.

HealthyTrailsBR – The prevalence of running-related injuries and cramps, and the description of personal and running characteristics in Brazilian trail runners: a cross-sectional study

BackgroundPhysical activity in natural environments, such as trail running, is a way to nurture physical and mental health. However, running has an inherent risk of musculoskeletal injuries. ObjectivesTo investigate the prevalence of running-related injuries (RRI) and cramps, and to describe the personal and training characteristics of Brazilian trail runners. MethodsA total of 1068 trail runners were included in this observational cross-sectional study. The participants had at least six months of trail running experience. The data were collected between April 2019 and February 2020 through an online and self-reported survey. ResultsThe point prevalence of RRIs was 39.2 % (95 % credible interval [CrI]: 36.3, 42.1). The body region with the highest point prevalence was the knee. The 12-month period prevalence of RRIs was 69.2 % (95 %CrI: 66.4, 72.0). The body region with the highest 12-month period prevalence was the lower leg. 1- and 12-month period prevalence of cramps was 19.5 % (95 %CrI: 17.1, 21.9) and 36.0 % (95 %CrI: 33.0, 38.8), respectively. Triceps surae was the muscle most affected by cramps. ConclusionsTwo in 5 (40 %) trail runners reported being injured at the time of data collection, and about 2 of 3 reported previous RRIs in the last 12 months. The most prevalent injured body regions were the knee and the lower leg. One in 5 trail runners reported cramps in the last month, increasing to 36 % in the last 12 months. Knowing better the characteristics of the population and the burden of health conditions may inform better decisions regarding implementation actions toward trail running practice.

The Impact of Sleep on Athletes Performance and Injury Risk

Introduction and purposeSleep is a critical component of an athlete's health, significantly influencing injury risk, performance, and recovery. It plays a vital role in the healing process, contributing to growth, repair, regeneration, and immunity. Current literature suggests that sleep quality impacts various aspects of athletic performance, including physical and cognitive abilities, recovery, injury risk, and mental well-being. This narrative review aims to explore the impact of sleep on the musculoskeletal system of athletes, particularly focusing on injury risk, performance, and recovery. It seeks to synthesize existing research to highlight the importance of sleep quality and duration in maintaining and enhancing athletic performance.Description of the state of knowledgeThe findings indicate that less than 7 hours of sleep is consistently associated with an increased risk of musculoskeletal injury, with athletes experiencing a 1.7 times higher risk if this sleep pattern persists for at least 14 days. Some studies also highlight that athletes obtaining fewer than 6 hours of sleep per day show significant performance declines and higher injury rates.SummaryWhile evidence clearly links certain sleep behaviors to increased musculoskeletal injury and pain, it is crucial to consider sleep as one aspect of an athlete's overall health and well-being. Adequate sleep is essential for optimal athletic performance, injury prevention, and recovery. Tailored sleep strategies should be integrated into training and recovery protocols to enhance the overall health and performance of athletes.

Inflammatory and Oxidant Responses to Arduous Military Training: Associations with Stress, Sleep, and Performance.

Arduous military training frequently consists of prolonged physical activity, sleep disturbance, and stress that increases musculoskeletal injury risk and performance decrements. Inflammatory and oxidative stress responses have been reported in response to arduous training, but with inconsistencies across markers and with under-representation of women. The purpose of the current report was to measure circulating inflammation and oxidative stress responses to military training and to correlate biomarkers with subjective measures of stress and sleep quality as well as military fitness test performance. Candidates undergoing the 10-week Marine Corps Officer Candidate School (OCS; 101 men; 62 women) were monitored, with demographic and questionnaire data collected, and blood drawn before and after OCS. Blood was analyzed for six markers of inflammation and three markers of oxidative stress. Associations between biomarkers and questionnaire and fitness test performance were tested. All measured inflammatory markers as well as plasma antioxidant capacity were elevated following OCS. The inflammatory increase was higher in women for several markers. Sleep disturbance and stress perception were associated with IL-6, IL-10 and CRP concentrations, suggesting that low sleep disturbance and stress perception were associated with low inflammatory load. Additionally, those with the highest inflammation at each time point performed worse on fitness tests than those with low inflammation. Following arduous military training, the circulating environment in a significant portion of officer candidates resembled chronic low-grade inflammation. This circulating inflammatory environment appeared worse with poor sleep, high stress perception, and poor fitness test performance, with utility observed for CRP, IL-6, and IL-10 as biomarkers of these responses. Since inflammation may contribute to musculoskeletal injury and performance decrements, minimizing chronic inflammation during military training should be explored.

Altered neural recruitment despite dual task performance recovery in athletes with repeat concussion.

Sports-related concussions (SRCs) pose significant challenges to college-aged athletes, eliciting both immediate symptoms and subacute cognitive and motor function impairment. While most symptoms and impairments resolve within weeks, athletes with repeat SRCs may experience heightened risk for prolonged recovery trajectories, future musculoskeletal injuries, and long-term neurocognitive deficits. This includes impaired dual task performance and altered neurophysiology that could persist across the lifespan and elicit future pathophysiology and neurodegeneration. Thus, it is imperative to improve our understanding of neurophysiology after SRC. This study aimed to investigate the impact of repeat SRCs on dual task performance and associated neural recruitment using functional near-infrared spectroscopy (fNIRS). A total of 37 college-aged athletes (ages 18-24) participated in this cross-sectional observational study. Among these athletes, 20 had a history of two or more SRCs, while 17 had never sustained a SRC and served as controls. Participants completed the Neuroimaging-Compatible Dual Task Screen (NC-DTS) while fNIRS measured neural recruitment in the frontoparietal attention network and the primary motor and sensory cortices. Behavioral analysis revealed that athletes with repeat SRCs exhibited comparable single task and dual task performance to control athletes. Additionally, dual task effects (DTE), which capture performance declines in dual tasks versus single tasks, did not significantly differ between groups. Notably, the cohort of athletes with repeat SRC in this study had a longer time since their last SRC (mean = 1.75 years) than majority of previous SRC studies. Neuroimaging results indicated altered neural recruitment patterns in athletes with multiple repeat SRCs during both single and dual tasks. Specifically, athletes with repeat SRCs demonstrated increased prefrontal cortex (PFC) activation during single motor tasks compared to controls (P < 0.001, d = 0.47). Conversely, during dual tasks, these same athletes exhibited reduced PFC activation (P < 0.001, d = 0.29) and primary motor cortex (M1) activation (P = 0.038, d = 0.16) compared to their single task activation. These findings emphasize the complex relationship between SRC history, dual task performance, and changes in neurophysiology. While athletes with repeat SRCs demonstrate recovery in behavioral dual task performance, persistent alterations in neural recruitment patterns suggest ongoing neurophysiological changes, possibly indicating compensatory neural strategies and inefficient neural resource allocation, even beyond symptom resolution and medical clearance. Understanding the compensatory neural recruitment strategies that support behavioral performance following repeat SRCs can inform return-to-play decisions, future musculoskeletal injury risk, and the long-term impact of SRCs on neurocognitive function.

Kinematics-Based Predictions of External Loads during Handcycling.

The increased risk of cardiovascular disease in people with spinal cord injuries motivates work to identify exercise options that improve health outcomes without causing risk of musculoskeletal injury. Handcycling is an exercise mode that may be beneficial for wheelchair users, but further work is needed to establish appropriate guidelines and requires assessment of the external loads. The goal of this research was to predict the six-degree-of-freedom external loads during handcycling from data similar to those which can be measured from inertial measurement units (segment accelerations and velocities) using machine learning. Five neural network models and two ensemble models were compared against a statistical model. A temporal convolutional network (TCN) yielded the best predictions. Predictions of forces and moments in-plane with the crank were the most accurate (r = 0.95-0.97). The TCN model could predict external loads during activities of different intensities, making it viable for different exercise protocols. The ability to predict the loads associated with forward propulsion using wearable-type data enables the development of informed exercise guidelines.

How boots affect the kinematics and kinetics of lower limb joints during walking compared to casual footwear

Boots are widely used by many people for various purposes, but their impact on gait biomechanics and injury risk is not well understood. This study investigated the effects of boots on walking biomechanics, compared to casual footwear. The lower limb joint kinematics and kinetics of 20 healthy male participants aged 20 to 30 years old were compared during self-paced walking with boots and shoes. The results showed that walking with boots is associated with greater hip extensor (P = 0.009) and ankle dorsiflexor (P < 0.001) moments in early stance, hip power generation (P < 0.001) and knee power absorption (P < 0.001) in early swing phase, hip abductor (P < 0.001) and knee adduction (P < 0.001) moments in the entire stance, net concentric work for the hip joint in sagittal (13.9%, P = 0.001) and frontal (21.7%, P = 0.002) planes. In contrast, the subtalar supinator moment in the entire stance (P < 0.001), ankle angular velocity in late stance (P < 0.001), and net concentric (− 42.7%, P < 0.001) and eccentric (− 44.6%, P = 0.004) works of subtalar joint were significantly lower in the boot condition. The compensatory adjustments in the hip and knee joints may result from ankle restrictions. While boots may aid those with ankle disorders, lower limb loading and the risk of musculoskeletal injuries and osteoarthritis could be increased. This study offers new perspectives on the biomechanical impact of boots on gait, potential prevention and treatment strategies of related injuries, and advancing footwear design.

Exploring Musculoskeletal Injuries Among Informal and Formal Carers of People With Dementia.

Carers of people with dementia manually handle the care recipients (eg, repetitive lifting, transferring, and pulling) as part of the care service, increasing the musculoskeletal injury risk to themselves. We aimed to determine the prevalence of musculoskeletal injuries among informal and formal carers of people with dementia and the perceived associated risk factors. Primary carers of people with dementia (26 males and 141 females) from Dementia Care Centers and Home Care programs completed a questionnaire providing information about (a) the carers' and their care recipients' characteristics, (b) musculoskeletal symptoms (via the Nordic Musculoskeletal Questionnaire) and related aspects, and (c) the caregiving activities exposing the carers to risk of musculoskeletal injury. Our results showed that 69.7% of informal and 86.7% of formal carers reported having more than 1 musculoskeletal injury, while 63.1% and 61.5%, respectively, reported having a musculoskeletal injury in the last year. Lower back had the highest injury prevalence (>10% for both groups). The 2 carer groups were not different in any of the variables. Our results reinforce calls for education and support of carers, regardless of their formal status, to enable injury-free and prolonged service provision.

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

IntroductionMusculoskeletal 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...

Movement Clearing Screens for Service Member Musculoskeletal Injury Risk Identification.

Pain during movement screens is a risk factor for musculoskeletal injury (MSKI). Movement screens often require specialized/clinical expertise and large amounts of time to administer. Evaluate if self-reported pain 1) with movement clearing screens is a risk factor for any MSKI, 2) with movement clearing screens is a risk factor for body region-specific MSKIs, and 3) with a greater number of movement clearing screens progressively increases MSKI risk. Retrospective cohort study. Field-based. Military Service members (n=4,222). Active-duty Service members self-reported pain during movement clearing screens (Shoulder Clearing, Spinal Extension, Squat-Jump-Land). MSKI data were abstracted up to 180-days post-screening. A Traffic Light Model grouped Service members if they self-reported pain during 0 (Green), 1 (Amber), 2 (Red), or 3 (Black) movement clearing screens. Cox proportional hazards models adjusted for age, gender, body mass index, and prior MSKI determined the relationships between pain during movement clearing screens with any and body region-specific MSKIs. Service members self-reporting pain during the Shoulder Clearing (adjusted-Hazard Ratio and 95% confidence interval (HRadj [95%CI]) =1.58 [1.37, 1.82]), Spinal Extension (HRadj=1.48 [1.28, 1.87]), or Squat- Jump-Land (HRadj=2.04 [1.79, 2.32]) tests were more likely to experience any MSKI compared to Service members reporting no pain. Service members with pain during the Shoulder Clearing (HRadj=3.28 [2.57, 4.19]), Spinal Extension (HRadj=2.80 [2.26, 3.49]), or Squat-Jump-Land (HRadj=2.07 [1.76, 2.43]) tests were more likely to experience an upper extremity, spine, back, and torso, or lower extremity MSKI, respectively, compared to Service members reporting no pain. The Amber (HRadj=1.69 [1.48, 1.93]), Red (HRadj=2.07 [1.73, 2.48]), and Black (HRadj=2.31 [1.81, 2.95]) cohorts were more likely to experience an MSKI compared to the Green cohort. Self-report movement clearing screens in combination with a Traffic Light Model provide clinician/non-clinician-friendly, expedient means to identify Service members at MSKI risk.

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

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

Risk Factors for Chronic Non-Communicable Diseases of Long-Haul Truck Drivers during the COVID-19 Pandemic: An Integrative Review.

Long-haul truck drivers are responsible for transporting goods valued at millions of dollars of the world economy, and may have their health affected by living and working conditions. This study analyzed and synthesized scientific findings about risk factors for the development of chronic non-communicable diseases in long-haul truck drivers. An integrative literature review was conducted. We identified 23 studies that met the inclusion criteria and evaluated the health of 7363 drivers. The biological risk factors identified were age, gender, race/ethnicity, genetics, and comorbidities, and were considered to be non-modifiable for chronic diseases. The behavioral risks considered to be modifiable were sedentary lifestyle, smoking, alcohol consumption, overweight, diet, stress, anxiety, and unfavorable socioeconomic conditions. Environmental risks involved working conditions such as the following: number of working hours per day, week, and month; time away from home; risk of musculoskeletal injury; and opportunities for rest, hours of sleep, and access to health services. The results were presented in two categories: (1) biological, behavioral, and environmental risks, and (2) general recommendations to promote physical, cognitive, and emotional health. Macro-structural changes are needed to reorganize work and rest, improve access to health services to control modifiable risk factors, and to support behavioral and environmental changes to reduce chronic non-communicable diseases and deaths.

Soulful Rhythm, Dancing Bodies: Spirituality, Pain Tolerance, and the Risk of Lower Extremity Musculoskeletal Injuries Among Classical Kathak Dancers of India

Background: Dance and dancers reflect happiness, sadness, passion, anger, and all other emotions as every single dancing movement carries a significant signal that goes beyond words. Kathak, an Indian classical dance form, requires a divine balance between the soul and the physical body. This balance allows for a high pain tolerance of the dancers, but the spiritual nature of this dance form also generates ignorance and disinterest in their health seeking behavior towards injuries. Objectives: This comprehensive narrative review is aimed at exploring and examining the prevalence of lower extremity musculoskeletal injuries among Kathak dancers and proposes management strategies for their prevention and treatment. Methods: This review is based on a search of relevant articles, research papers, books and book chapters conducted across a wide array of online sources, utilizing the search engines like PubMed, Medline, CrossRef; etc. Considering the inclusion criterion, the review process included three stages: initial assessment of papers through title and abstract review, a detailed examination of relevant items, and systematic compilation of pertinent information into a categorized table under topical headings. Results: The review finds that the majority of injuries were reported in the foot and ankle region of dancers practicing Kathak. Conclusion: There is a need to develop supplementary exercise training programs and also spread awareness among dancers regarding their physical health and seeking medical care in time to delay/prevent lower extremity injuries.

A - 51 Examining the Role of Cognition in Lower Extremity Musculoskeletal Injury and Concussion Risk in Elite Athletes

A - 51 Examining the Role of Cognition in Lower Extremity Musculoskeletal Injury and Concussion Risk in Elite Athletes

Trunk and Lower Extremity Biomechanics in Female Athletes With and Without a Concussion History.

Athletes with a history of concussion are at a greater risk for lower extremity musculoskeletal injury. Female athletes may be at an even greater risk than male athletes. Previous researchers on postconcussion landing biomechanics have focused on the lower extremities, but the trunk plays a crucial role as an injury risk factor. To compare lower extremity and trunk biomechanics during jump-landing and cutting maneuvers between female athletes with and those without a concussion history. Cross-sectional study. Biomechanics laboratory. A total of 26 athletes (mean ± SD age = 19.0 ± 1.3 years, height = 1.68 ± 0.07 m, mass = 64.02 ± 6.76 kg, body mass index = 22.58 ± 1.97 kg/m2; median [interquartile range] time since most recent concussion = 37.5 months [25.0 months, 65.8 months]) with a concussion history and 38 athletes (age = 19.0 ± 1.1 years, height = 1.71 ± 0.08 m, mass = 64.72 ± 9.45 kg, body mass index = 22.14 ± 1.80 kg/m2) without a concussion history. Peak kinetics (vertical ground reaction force, vertical loading rate, external knee-abduction moment, and external knee-flexion moment) and kinematics (trunk-flexion angle, trunk lateral-bending angle, ankle-dorsiflexion angle, knee-flexion angle, knee-abduction angle, and hip-flexion angle) were obtained during the eccentric portion of jump-landing and cutting tasks. Separate 2 (group) × 2 (limb) between- and within-factors analyses of covariance were used to compare outcomes between groups. We covaried for time since the most recent concussion and the limb that had a history of musculoskeletal injury. Athletes with a concussion history displayed a greater peak knee-abduction angle in their nondominant limb than their dominant limb (P = .01, ηp2 = 0.107) and the nondominant limb of athletes without a concussion history (P = .02, ηp2 = 0.083) during jump landing. They also had less trunk lateral bending during cutting compared with athletes without a concussion history (P = .005, ηp2 = 0.126). Our results indicated landing biomechanics are different between female athletes with and those without a concussion history. This finding may be due to impairments in neuromuscular control postconcussion that may ultimately increase the risk of subsequent lower extremity injury, although further research is warranted given the cross-sectional nature of our study.

Allostatic Load Is Associated with Overuse Musculoskeletal Injury during US Marine Corps Officer Candidates School.

Overuse musculoskeletal injuries (MSKIs) remain a significant medical challenge in military personnel undergoing military training courses; a further understanding of the biological process leading to overuse MSKI development and biological signatures for injury risk are warranted. The purpose of this study was to determine the association between overuse MSKI occurrence and physiological characteristics of allostatic load (AL) characterized as maladaptive biological responses to chronic stress measured by wearable devices in US Marine Corps officer candidates during a 10-week training course. Devices recorded energy expenditure (EE), daytime heart rate (HR), sleeping HR, and sleep architecture (time and percent of deep, light, REM sleep, awake time, total sleep). Flux was calculated as the raw or absolute difference in the average value for that day or night and the day or night beforehand. Linear mixed-effect model analysis accounting for cardiorespiratory fitness assessed the association between overuse MSKI occurrence and device metrics (α = 0.05). Sixty-nine participants (23 females) were included. Twenty-one participants (eight females) sustained an overuse MSKI. Overuse MSKI occurrence in male participants was positively associated with daytime HR (β = 5.316, p = 0.008), sleeping HR (β = 2.708, p = 0.032), relative EE (β = 8.968, p = 0.001), absolute flux in relative EE (β = 2.994, p = 0.002), absolute EE (β = 626.830, p = 0.001), and absolute flux in absolute EE (β = 204.062, p = 0.004). Overuse MSKI occurrence in female participants was positively associated with relative EE (β = 5.955, p = 0.026), deep sleep time (β = 0.664, p < 0.001), %deep sleep (β = 12.564, p < 0.001) and negatively associated with absolute flux in sleeping HR (β = -0.660, p = 0.009). Overuse MSKI occurrences were associated with physiological characteristics of AL including chronically elevated HR and EE and greater time in restorative sleep stages, which may serve as biological signatures for overuse MSKI risk.

Playing surface and sport contact status modulate time to lower extremity musculoskeletal injury at a greater level than concussion history among collegiate student-athletes

ObjectivesWhile previous investigations have demonstrated a positive correlation between previous concussion and risk of subsequent lower extremity musculoskeletal injury (LEMSKI), the effect of sport- and patient-specific factors on time to injury has not been thoroughly described. This study's main objective was to evaluate the relationship between prior concussion and time to LEMSKI among a population of collegiate student-athletes. Secondary objectives were to evaluate the relationship between playing surface, sport contact status, and biologic sex on time to LEMSKI. We hypothesized that those with previous concussions, those competing on synthetic surfaces, and those competing in collision sports would experience decreased latency to LEMSKI overall. MethodsA retrospective observational analysis of National Collegiate Athletic Association (NCAA) Division I student-athletes was conducted utilizing a mixed linear model analysis with contrasts. Inclusion criteria included participation in the Pac-12 Health Analytics Program with a documented LEMSKI between 2017 and 2020. Exclusion criteria included concurrent concussion and LEMSKI, injury resulting in serious morbidity or mortality, and incomplete medical record. Participants were classified by whether they sustained a concussion prior to LEMSKI in each athletic season. ResultsOf 1179 athletes included, 1140 had no previous concussion and 37 had a previous concussion. There was no observed effect of previous concussion (F ​= ​0.038; p ​= ​0.846) on time to LEMSKI overall. Student-athletes competing on constructed surfaces sustained a subsequent LEMSKI 14.5 days sooner (SE ​= ​5.255; p ​= ​0.045), and those competing on organic surfaces sustained a subsequent LEMSKI 23.5 days sooner (SE ​= ​4.018; p ​< ​0.001) in the season than those competing on synthetic surfaces. Contact sport student-athletes sustained a subsequent LEMSKI 52.1 days sooner than collision sport student-athletes (SE ​= ​5.248; p ​< ​0.001), and limited contact sport student-athletes sustained a subsequent LEMSKI 42.29 days sooner than collision sport student-athletes (SE ​= ​4.463; p ​< ​0.001). There was no observed effect of biologic sex (F ​= ​0.602; p ​= ​0.438) on time to LEMSKI overall. ConclusionThere was no observed impact of concussion on time on LEMSKI overall in this collegiate athletic population. Contact sports were associated with decreased time to LEMSK, while synthetic surfaces were associated with increased time to LEMSKI in this population. There was no observed impact of biologic sex on time to LEMSKI. Level of evidenceCase-control, level of evidence III.

A machine learning framework to classify musculoskeletal injury risk groups in military service members.

Musculoskeletal injuries (MSKIs) are endemic in military populations. Thus, it is essential to identify and mitigate MSKI risks. Time-to-event machine learning models utilizing self-reported questionnaires or existing data (e.g., electronic health records) may aid in creating efficient risk screening tools. A total of 4,222 U.S. Army Service members completed a self-report MSKI risk screen as part of their unit's standard in-processing. Additionally, participants' MSKI and demographic data were abstracted from electronic health record data. Survival machine learning models (Cox proportional hazard regression (COX), COX with splines, conditional inference trees, and random forest) were deployed to develop a predictive model on the training data (75%; n = 2,963) for MSKI risk over varying time horizons (30, 90, 180, and 365 days) and were evaluated on the testing data (25%; n = 987). Probability of predicted risk (0.00-1.00) from the final model stratified Service members into quartiles based on MSKI risk. The COX model demonstrated the best model performance over the time horizons. The time-dependent area under the curve ranged from 0.73 to 0.70 at 30 and 180 days. The index prediction accuracy (IPA) was 12% better at 180 days than the IPA of the null model (0 variables). Within the COX model, "other" race, more self-reported pain items during the movement screens, female gender, and prior MSKI demonstrated the largest hazard ratios. When predicted probability was binned into quartiles, at 180 days, the highest risk bin had an MSKI incidence rate of 2,130.82 ± 171.15 per 1,000 person-years and incidence rate ratio of 4.74 (95% confidence interval: 3.44, 6.54) compared to the lowest risk bin. Self-reported questionnaires and existing data can be used to create a machine learning algorithm to identify Service members' MSKI risk profiles. Further research should develop more granular Service member-specific MSKI screening tools and create MSKI risk mitigation strategies based on these screenings.