Comparing the Drop Vertical Jump Tracking Performance of the Azure Kinect to the Kinect V2.

Traditional motion analysis systems are impractical for widespread screening of non-contact anterior cruciate ligament (ACL) injury risk. The Kinect V2 has been identified as a portable and reliable alternative but was replaced by the Azure Kinect. We hypothesize that the Azure Kinect will assess drop vertical jump (DVJ) parameters associated with ACL injury risk with similar accuracy to its predecessor, the Kinect V2. Sixty-nine participants performed DVJs while being recorded by both the Azure Kinect and the Kinect V2 simultaneously. Our software analyzed the data to identify initial coronal, peak coronal, and peak sagittal knee angles. Agreement between the two systems was evaluated using the intraclass correlation coefficient (ICC). There was poor agreement between the Azure Kinect and the Kinect V2 for initial and peak coronal angles (ICC values ranging from 0.135 to 0.446), and moderate agreement for peak sagittal angles (ICC = 0.608, 0.655 for left and right knees, respectively). At this point in time, the Azure Kinect system is not a reliable successor to the Kinect V2 system for assessment of initial coronal, peak coronal, and peak sagittal angles during a DVJ, despite demonstrating superior tracking of continuous knee angles. Alternative motion analysis systems should be explored.

Practitioners' perspective of non-contact injury risk factors and injury prevention programming in professional North American male soccer.

OBJECTIVE: To evaluate non-contact injury prevention strategies of professional men's soccer clubs in elite North American league soccer. To understand the application, perceived effectiveness and barriers to implementation. DESIGN: Online cross-Sectional Study. SETTING: North American elite soccer teams. PARTICIPANTS: 96 medical and performance support staff of elite North American teams. MAIN OUTCOME MEASURE: The survey consisted of 20 questions and captured 1) practitioners' demographics; 2) perceptions of risk factors; 3) the use of assessment and monitoring strategies; and 4) perceptions of the implementation of injury prevention programmes'. RESULTS: Injury prevention programmes were perceived as 'effective' (Median 4, Interquartile range 4-4) and reduced injury rates (n = 94, 98%, 95 CI% 93 to 99). A range of potential risk factors were rated as "very important" (4.58 ± 0.52 Likert scale points; mean ± standard deviation). A multi-disciplinary approach to the design, application and monitoring of programmes was generally adopted. Competing training priorities (n = 75, 78%, 95 CI% 69 to 85) and game schedules (n = 71, 74%, 95 CI% 64 to 82) were the most prevalent barriers to injury prevention implementation. CONCLUSIONS: Injury prevention programmes were perceived as effective in reducing non-contact injuries. Managing the conflicting priorities between scheduling training, tactical and conditioning goals were considered the key barriers to desired implementation.

Menstrual Cycle Hormone Relaxin and ACL Injuries in Female Athletes: A Systematic Review.

Background: Female athletes are at increased risk for anterior cruciate ligament (ACL) injuries. The influence of hormonal variation on female ACL injury risk remains ill-defined. Recent data suggests that the collagen-degrading menstrual hormone relaxin may cyclically impact female ACL tissue quality. This review aims to identify any correlation between menstrual relaxin peaks and rates of female ACL injury. Methods: A systematic review was performed, utilizing the MEDLINE, EMBASE, and CINAHL databases. Included studies had to directly address relaxin/female ACL interactions. The primary outcome variable was relaxin proteolysis of the ACL, at cellular, tissue, joint, and whole-organism levels. The secondary outcome variable was any discussed method of moderating relaxin levels, and the clinical results if available. Results: AllThe numerous relaxin receptors on female ACLs upregulate local collagenolysis and suppress local collagen production. Peak serum relaxin concentrations (SRC) occur during menstrual cycle days 21-24; a time phase associated with greater risk of ACL injury. Oral contraceptives (OCPs) reduce SRC, with a potential ACLprotective effect. Conclusion: A reasonable correlative and plausible causative relationship exists between peak relaxin levels and increased risk of ACL injury in females, and further investigation is warranted. Level of Evidence: III.

Child pedestrian safety training in virtual reality: How quickly do children achieve adult functioning and what individual differences impact learning efficiency?

INTRODUCTION: Pedestrian injuries represent a leading cause of child death globally. One prevention strategy is teaching children street-crossing skills. Virtual reality (VR) has emerged as a strategy to offer repeated street-crossing practice and overcome ethical barriers of training children in live traffic. This study addressed two questions pertinent to implementation of child pedestrian safety training within VR: (a) how much training do children require to achieve adult street-crossing competency, and (b) what individual differences might facilitate children to acquire that competency more efficiently? METHODS: Five hundred 7- and 8-year-olds were recruited. Children completed pedestrian safety training within VR for up to 25 thirty-minute training sessions until they achieved adult levels of mastery. At baseline, four cognitive-perceptual skills (visual memory, visual perception, processing speed, working memory) and parent-reported externalizing symptomatology were assessed. RESULTS: On average, children achieved adult pedestrian safety competency after 10.0 training sessions (SD = 4.8). Just one child (<1%) failed to achieve adult pedestrian functioning after 25 training sessions. In univariate analyses, boys took slightly longer than girls to achieve adult functioning, and visual memory, visual perception, processing speed, working memory, and fewer externalizing symptoms were all positively associated with shorter time to mastery. In a multivariable model, only child age was a statistically significant predictor. CONCLUSION: Almost all participants achieved adult street-crossing skills competency through VR training, although they required about 10 sessions on average. Analysis of predictor variables confirmed that nearly all 7- and 8-year-olds are trainable. PRACTICAL APPLICATION: Implementation of VR pedestrian safety training is recommended, but must be conducted cautiously to ensure children are not permitted to engage independently in traffic until they are assessed and demonstrate sufficient skills.

Child drowning mortality in Israel: Trends and measures for prevention.

INTRODUCTION: In this study, we use the media-based database of Beterem-Safe Kids Israel, to provide a 15-year review of unintentional fatal childhood drowning in Israel, between 2008 and 2022. METHOD: It total, we identified 257 cases of child mortality due to drowning during this period. RESULTS: Our results demonstrate a gradual rise in childhood mortality due to drowning, from 72 cases in 2008-2012, to 85 cases in 2013-2017, and to 100 cases in 2018-2022. Especially worth noting is the increase in childhood drowning in domestic swimming pools. We point to a link between low socioeconomic status and cases of drowning, showing that the risk of drowning extends beyond a mere matter of caregiver inattention. We recommend a series of regulatory and legislative steps to reduce fatal childhood drowning, including fencing built around domestic swimming pools, extending lifeguard activity hours, adding declared beaches, forming programs of safe behavior in water environments for adolescents, and establishing swimming lessons during the 2nd grade, for all populations. We further recommend that a special focus will be put in municipalities situated at the bottom of the socioeconomic index.

Age, sex, sensation-seeking, and road-crossing: How does risk context impact children's street-crossing?

OBJECTIVE: Child pedestrian injuries are a significant public health problem, largely because children have underdeveloped cognitive-perceptual capacity to judge traffic unsupervised. This study used a virtual reality (VR) environment to examine the impact of children's age, as well as sex and sensation-seeking personality, on pedestrian behavior in different risk contexts. METHODS: 405 Norwegian children (7-10-year-olds) engaged in street-crossing scenarios within a VR environment. Children crossed a bicycle path and urban roadway six times, each with increasing density and complexity of traffic. Hits and near hits were recorded. Self-reported sensation-seeking personality was assessed. RESULTS: Children were more likely to experience crashes in the tasks that offered higher probability risk. Overall, 106 children crossed safely in all tasks. Dangerous crossings were associated with male sex, higher thrill and intensity seeking personality, and denser traffic. Age was not related to any traffic safety outcomes. CONCLUSION: As expected, children were struck by vehicles more often in complex traffic contexts than in less complex ones. The results support previous findings and suggest that boys and sensation seekers have elevated risk of pedestrian injury, and that individual differences in children, rather than age alone, must be considered when determining if children are capable of safely negotiating traffic unsupervised.

Characterizing trauma encounters among patients with language other than English preference at a level 1 trauma center's emergency department.

Objectives: Injury-related visits constitute a sizeable portion of emergency department (ED) visits in the United States. Individuals with language other than English (LOE) preference face barriers to healthcare and visits for traumatic injury may be the first point of contact with the healthcare system. Yet, the prevalence of traumatic injuries in this population is relatively unknown. Our objective was to characterize the prevalence and purpose of trauma encounters, and healthcare utilization, among a LOE cohort. Methods: We conducted a retrospective chart review of LOE patients who presented for a trauma encounter at a level 1 trauma and emergency care center between January 1, 2019 and December 31, 2021. LOE participants were identified by utilization of video-based language interpretive services. Variables evaluated included injury patterns and primary and subspeciality healthcare utilization. Quantitative analysis of categorical and continuous variables was performed. Results: A total of 429 patients were included. Most patients presented for one trauma encounter and the majority spoke Spanish. The most common causes of injury were motor vehicle collisions (MVCs) (28.5%, n = 129), ground-level falls (15.9%, n = 72), and falls from heights (14.2%, n = 64). Occupational injuries made up 27.2% of trauma encounters (n = 123) and only 12.6% (n = 54) of patients had a primary care visit. Conclusion: Our findings highlight the need for increased research and attention to all causes of injury, especially MVCs and occupational injuries, among those with LOE preference. Results reaffirm an underutilization of healthcare among this population and the opportunity for trauma encounters as points of access to care.

Efficacy of multicomponent interventions on injury risk among ice and snow sports participants-a systematic review and meta-analysis.

BACKGROUND: Ice and snow sports, which are inherently high risk due to their physically demanding nature, pose significant challenges in terms of participant safety. These activities increase the likelihood of injuries, largely due to reduced bodily agility and responsiveness in cold, often unpredictable winter environments. The critical need for effective injury prevention in these sports is emphasized by the considerable impact injuries have on the health of participants, alongside the economic and social costs associated with medical and rehabilitative care. In the context of ice and snow sports environments, applying the E principles of injury prevention to evaluate intervention measures can guide the implementation of future sports safety and other health promotion intervention measures in this field. When well executed, this approach can substantially reduce both the frequency and severity of injuries, thereby significantly enhancing the safety and long-term viability of these challenging sports. OBJECTIVE: The objective of this study was to rigorously assess and statistically substantiate the efficacy of diverse injury prevention strategies in ice and snow sports, aiming to bolster future safety measures with solid empirical evidence. DESIGN: Systematic review and meta-analysis. METHODS: The overarching aim of this research was to meticulously aggregate and scrutinize a broad spectrum of scholarly literature, focusing on the quantifiable efficacy of diverse, multicomponent intervention strategies in mitigating the incidence of injuries within the realm of ice and snow sports. This endeavour entailed an exhaustive extraction of data from esteemed academic databases, encompassing publications up to September 30, 2023. In pursuit of methodological excellence and analytical rigor, the study employed advanced bias assessment methodologies, notably the AMSTAR 2 and GRADE approaches, alongside sophisticated random-effects statistical modelling. This comprehensive approach was designed to ensure the utmost validity, reliability, and scholarly integrity of the study's findings. RESULTS: Fifteen papers, including 9 randomized controlled trials, 3 case‒control studies, and 3 cohort studies with 26,123 participants and 4,382 injuries, were analysed. The findings showed a significant reduction in injury rates through various interventions: overall injury prevention (RR = 0.50, 95% CI 0.42-0.63), educational training (RR = 0.50, 95% CI 0.34-0.73), educational videos (RR = 0.53, 95% CI 0.34-0.81), protective equipment (RR = 0.64, 95% CI 0.46-0.87), and policy changes (RR = 0.28, 95% CI 0.16-0.49). Subgroup analysis revealed potential heterogeneity in compliance (p = 0.347). Compared to controls, multicomponent interventions effectively reduced injury rates. CONCLUSION: This systematic review and meta-analysis demonstrated that multicomponent interventions significantly prevent injuries in ice and snow sports. By applying the E principles of injury prevention and constructing a framework for practical injury prevention research in ice and snow sports, we can gradually shift towards a systemic paradigm for a better understanding of the development and prevention of sports injuries. Moreover, sports injury prevention is a complex and dynamic process. Therefore, high-quality experiments in different scenarios are needed in future research to provide more reliable evidence, offer valuable and relevant prevention information for practitioners and participants, and help formulate more effective preventive measures in practice.

Headgear use in girls' lacrosse-stakeholders not ready for change.

Purpose: Mandating headgear for field players in girls' lacrosse to reduce head injuries, including concussion, has been heavily debated. However, research regarding the need and effectiveness of mandated headgear use in girls' lacrosse is still developing. Therefore, this qualitative study aimed to identify the need for and barriers to the development of mandated headgear use policies in girls' lacrosse in Ohio. Methods: We conducted six virtual focus groups, three with concussion experts (clinicians and researchers) and three with girls' lacrosse stakeholders (high school players, parents, coaches, and officials). A focus group guide was developed to explore study participants' perceptions and opinions on concussion in girls' lacrosse, headgear use among players, and policies and policy development related to headgear use or a headgear mandate. We developed the codebook using an inductive and iterative approach based on focus group transcripts and used ATLAS.TI to code and analyze the transcript data. Results: Concussion experts and stakeholders understood the potential consequences of concussion but did not perceive concussion as a pervasive problem in girls' lacrosse. The prevention of head and facial injuries was regarded as a potential benefit of headgear use. However, stakeholders expressed that the myriad of arguments discussed opposing mandated headgear use including increased aggressive play and/or targeting, concerns over changes in the game, and cost strongly outweighed the benefits. Finally, both concussion experts and stakeholders identified multiple organizations, including USA Lacrosse, who could act as facilitators and/or barriers to developing, enacting, and implementing headgear policies. Conclusions: Concussion experts and stakeholders identified possible reasons for headgear use related to injury prevention but also identified several important barriers to the development of a headgear mandate for girls' lacrosse in Ohio.

Emergency Department Presentations for Injuries Following Agency-Notified Child Maltreatment: Results From the Childhood Adversity and Lifetime Morbidity (CALM) Study.

Child maltreatment (CM) is associated with negative health outcomes in adulthood, including deliberate self-harm (DSH), suicidal behaviours, and victimisation. It is unknown if associations extend to emergency department (ED) presentations for non-DSH related injuries. Birth cohort study data was linked to administrative health data, including ED presentations for non DSH related injuries and agency-reported and substantiated notifications for CM. Adjusted analyses (n = 6087) showed that any type of agency-reported notification for CM was significantly associated with increased odds of ED presentation for injuries (aOR = 1.57; 95% CI 1.32-1.87). In moderation analyses, women yielded significantly higher odds of notified and substantiated physical abuse, substantiated emotional abuse, and being subject to more than one type of substantiated abuse than males. ED presentations for injuries could be a proxy for risky behaviours, disguised DSH/suicidal behaviours, or physical abuse. The consistent findings in women may point to victimisation via interpersonal violence.

Identifying emerging hot spots of road traffic injury severity using spatiotemporal methods: longitudinal analyses on major roads in Ghana from 2005 to 2020.

BACKGROUND: Although road traffic injuries and deaths have decreased globally, there is substantial national and sub-national heterogeneity, particularly in low- and middle-income countries (LMICs). Ghana is one of few countries in Africa collecting comprehensive, spatially detailed data on motor vehicle collisions (MVCs). This data is a critical step towards improving roadway safety, as accurate and reliable information is essential for devising targeted countermeasures. METHODS: Here, we analyze 16 years of police-report data using emerging hot spot analysis in ArcGIS to identify hot spots with trends of increasing injury severity (a weighted composite measure of MVCs, minor injuries, severe injuries, and deaths), and counts of injuries, severe injuries, and deaths along major roads in urban and rural areas of Ghana. RESULTS: We find injury severity index sums and minor injury counts are significantly decreasing over time in Ghana while severe injury and death counts are not, indicating the latter should be the focus for road safety efforts. We identify new, consecutive, intensifying, and persistent hot spots on 2.65% of urban roads and 4.37% of rural roads. Hot spots are intensifying in terms of severity and frequency on major roads in rural areas. CONCLUSIONS: A few key road sections, particularly in rural areas, show elevated levels of road traffic injury severity, warranting targeted interventions. Our method for evaluating spatiotemporal trends in MVC, road traffic injuries, and deaths in a LMIC includes sufficient detail for replication and adaptation in other countries, which is useful for targeting countermeasures and tracking progress.

Development, validation and reliability of a questionnaire to evaluate coaches' and players' perceptions, learning, and resources regarding the ruck in rugby union.

Background: The lack of a reliable research tool for assessing the attitudes, behaviours, and learning resources of rugby coaches and players regarding the ruck event is a significant gap in rugby research. Objectives: This study aimed to adapt an existing questionnaire focused on the tackle event and to validate and establish the reliability of the instrument. The questionnaire explores the attitudes, behaviours, and learning resources of rugby coaches and players, with a focus on the ruck event and its impact on coach and player development, as well as coaching practices. Methods: A seven-step design process was followed to validate the questionnaire's content, construct, clarity, and relevance. A panel of 12 experts evaluated the questionnaire, followed by a test-retest procedure involving 15 coaches and 16 players, highlighting the effectiveness of this questionnaire, and emphasising its potential to generate data that can impact the field of rugby coaching and player development. Results: The questionnaire was deemed appropriate and clear by the expert panel, with an average completion time of 22 minutes. Moderate to good agreement was observed among players (ICC Agreement = 0.71) and coaches (ICC Agreement = 0.88), with high response consistency (ICC Consistency = 0.71 for players and 0.87 for coaches). Significant agreement was also found in Kendall's W scores (players = 0.85, coaches = 0.93, p<0.01). Conclusion: This study presents a developed questionnaire noted for its clarity, reliability, and consistency. It serves as a valuable tool for future rugby research, with the potential to impact coach and player development significantly.

Anterior Cruciate Ligament Injury Prevention Programs in Welsh Netball: A Survey of Knowledge, Implementation and Barriers Amongst Players and Coaches.

Background Anterior cruciate ligament (ACL) injury prevention programs can reduce injury risk in various sports. The perception of ACL injury prevention programs amongst professional netball players and coaches has not been studied. Purpose The aim of this study was to determine (1) the level of awareness and experience of ACL injury prevention programs, (2) the use of ACL injury prevention programs, and (3) barriers and potential facilitators to implementing a sustainable ACL injury prevention program in netball. Materials and methods Female netball players representing Welsh senior and under-21 teams and elite and amateur coaches were invited electronically to participate in this web-based cross-sectional observational study between 1st May and 31st July 2021. Information on ACL injury susceptibility and seriousness, knowledge, experience, and implementation of ACL injury prevention programs were ascertained. Results Twenty-eight players (78%) and 29 coaches (13%) completed the questionnaire. Seventeen (61%) players and 15 (52%) coaches reported that female athletes were at greater risk of sustaining ACL injuries. Over 90% of respondents identified netball as high-risk, whilst 89% (n=25) of players and 76% (n=22) of coaches reported these injuries to be preventable. Only two (7%) players and six (21%) coaches utilised an ACL injury prevention program with a lack of time and engagement from coaches and players identified. The majority of respondents indicated that their club has neither promoted, advocated the use nor demonstrated exercises for ACL injury prevention. Over 90% of respondents would utilise an ACL injury prevention program if it minimised players' risk with appropriate information and demonstration of exercises. Conclusion This study highlights limited knowledge of female athletes' increased susceptibility to ACL injuries amongst players and coaches with a lack of communication and education on ACL injury prevention programs between sporting associations, coaches, and players. However, the results demonstrate willingness amongst both players and coaches to implement an ACL injury prevention program in netball.

Traffic safety comprehensive evaluation of urban tunnel visual guiding system based on extension matter-element model: a case study in tunnel curves.

OBJECTIVE: The visual guiding system, as a tunnel traffic safety improvement method by using visual guiding facilities to actively guide driving safely, has been widely used in countries with many tunnels, in recent years. This paper aims to quantitatively study the comprehensive evaluation of traffic safety of the visual guiding system in tunnels, which has certain engineering application value and can provide support for the quantitative evaluation and optimal design of tunnel traffic safety. METHODS: Based on the analysis of the relevant factors of urban tunnel traffic safety, a multi-factor comprehensive evaluation system with 5 upper-level indicators and 12 basic-level indicators was proposed. Considering the independent and incompatible indicators, a comprehensive evaluation method of traffic safety of the visual guiding system in urban tunnels was constructed by using the extension matter-element model. Taking the scene of 4 types of tunnel curves, such as no facilities, horizontal stripe, chevron alignment sign, and LED arch, as examples, the comprehensive evaluation of various schemes were carried out by using simulation tests. RESULTS: The traffic safety comprehensive evaluation system of visual guiding system in urban tunnels can be analyzed from five aspects: perception reaction, guidance ability, driver factor, driving task, and facility appearance. The results demonstrated significant the comprehensive evaluation result of the target level of scene 1 was L4, scene 2 was L3, scene 3 was L2, and scene 4 was L1. That is, the final results of the comprehensive evaluation of the four scenes were poor, medium, good, and very good, respectively. CONCLUSIONS: In the scheme of visual guiding system for urban tunnel curves, the effectiveness of the three types of designs, from high to low, was the LED arch, chevron alignment sign, and horizontal stripe, and the safety of the scene without facilities was the lowest. Hence, setting the LED arch in the urban tunnel curve has a good effect in the aspects of guidance ability, sight distance, and sight zone, and is conducive to the driver's perception reaction and driving task.

Acute effects of Nordic hamstring exercise on hip and knee joints proprioception.

BACKGROUND AND OBJECTIVES: Nordic Hamstring Exercise (NHE) is one of the best exercises proposed for injury prevention of hamstring muscles. However, its effects on lower extremity proprioception are unclear. The aim of this study was to investigate the immediate effects of a single bout of NHE on hip and knee joints' proprioception. METHODS: Forty collegiate male soccer players participated in this study with a mean age of 22.85 ± 1.82 years and were randomized into either control (n = 20) or experimental (n = 20) groups. Each subject participated in pre-test measurements in which hip and knee active joints position sense (JPS) were assessed in standing and lying tasks using the image-capturing method. The experimental group then performed three sets of NHE with 10 repetitions in each set, while the control group rested for 10 min. Paired and independent t-tests were used for calculating the differences within and between groups on SPSS software, respectively. The level of significance was P ≤ 0.05. RESULTS: Hip JPS in the lying task and knee JPS in both of the standing and lying tasks were impaired significantly after performing a single bout of NHE (P ≤ 0.05). However, the effects of this exercise on hip JPS in the standing task were not significant (P ≥ 0.05). CONCLUSIONS: NHE performing with three sets of 10 repetitions can significantly impair hip and knee JPS immediately after exercise and reduce the proprioception acuity of the lower limbs. It is recommended to perform this exercise at a time rather than before training or match sessions.

Single-legged landing behavior of high school basketball players with chronic ankle instability.

OBJECTIVES: Anterior cruciate ligament injury is one of the most serious ligamentous injuries. The purpose is to compare the impact of the ankle joint on the knee during landing between athletes with chronic instability and a control group (coper group) and to verify the effects of the kinetic chain from other joints. DESIGN: Prospective study. SETTING: High school basketball. PARTICIPANTS: Participants were 62 female high school basketball players who had participated in team sports for >6 months. MAIN OUTCOME MEASURES: Player joint angles, movements, and moments. RESULTS: The knee valgus moment was significantly higher in the chronic ankle instability group than in the coper group (20%-60% [p < 0.01]; 80%-100% [p < 0.05]) during landing motion. The knee valgus moment was also significantly higher during the change from the maximum knee joint flexion position to the maximum extension (p < 0.05). In addition, the landing motions of the chronic instability group may have utilized suboptimal compensatory motor strategy on the sagittal plane, depending heavily on the knee joint's abduction moment. CONCLUSIONS: Our findings indicate that the chronic ankle instability group uses a different landing strategy pattern than the coper group by changing the joint moment and joint angle during landing, which may increase the risk of anterior cruciate ligament injury.

Application of Machine Learning Methods to Investigate Joint Load in Agility on the Football Field: Creating the Model, Part I.

Laboratory studies have limitations in screening for anterior cruciate ligament (ACL) injury risk due to their lack of ecological validity. Machine learning (ML) methods coupled with wearable sensors are state-of-art approaches for joint load estimation outside the laboratory in athletic tasks. The aim of this study was to investigate ML approaches in predicting knee joint loading during sport-specific agility tasks. We explored the possibility of predicting high and low knee abduction moments (KAMs) from kinematic data collected in a laboratory setting through wearable sensors and of predicting the actual KAM from kinematics. Xsens MVN Analyze and Vicon motion analysis, together with Bertec force plates, were used. Talented female football (soccer) players (n = 32, age 14.8 ± 1.0 y, height 167.9 ± 5.1 cm, mass 57.5 ± 8.0 kg) performed unanticipated sidestep cutting movements (number of trials analyzed = 1105). According to the findings of this technical note, classification models that aim to identify the players exhibiting high or low KAM are preferable to the ones that aim to predict the actual peak KAM magnitude. The possibility of classifying high versus low KAMs during agility with good approximation (AUC 0.81-0.85) represents a step towards testing in an ecologically valid environment.

Head Acceleration Events During Tackle, Ball-Carry, and Ruck Events in Professional Southern Hemisphere Men's Rugby Union Matches: A Study Using Instrumented Mouthguards.

OBJECTIVES: Describe head acceleration events (HAEs) experienced by professional male rugby union players during tackle, ball-carry, and ruck events using instrumented mouthguards (iMGs). DESIGN: Prospective observational cohort. METHODS: Players competing in the 2023 Currie Cup (141 players) and Super Rugby (66 players) seasons wore iMGs. The iMG-recorded peak linear acceleration (PLA) and peak angular acceleration (PAA) were used as in vivo HAE approximations and linked to contact-event data captured using video analysis. Using the maximum PLA and PAA per contact event (HAEmax), ordinal mixed-effects regression models estimated the probabilities of HAEmax magnitude ranges occurring, while accounting for the multilevel data structure. RESULTS: As HAEmax magnitude increased the probability of occurrence decreased. The probability of a HAEmax ≥15g was 0.461 (0.435-0.488) (approximately 1 in every 2) and ≥45g was 0.031 (0.025-0.037) (1 in every 32) during ball carries. The probability of a HAEmax >15g was 0.381 (0.360-0.404) (1 in every 3) and >45g 0.019 (0.015-0.023) (1 in every 53) during tackles. The probability of higher magnitude HAEmax occurring was greatest during ball carries, followed by tackles, defensive rucks and attacking rucks, with some ruck types having similar profiles to tackles and ball carries. No clear differences between positions were observed. CONCLUSION: Higher magnitude HAEmax were relatively infrequent in professional men's rugby union players. Contact events appear different, but no differences were found between positions. The occurrence of HAEmax was associated with roles players performed within contact events, not their actual playing position. Defending rucks may warrant greater consideration in injury prevention research.

Racial and Ethnic Differences in Time to Completion of Academic Enrichment Program Applications.

INTRODUCTION: Diversity in healthcare and research is integral to serving our increasingly diverse population. Access to academic enrichment programs, an important pathway to science, technology, engineering, and mathematics (STEM) careers promotes educational attainment through academic preparation and increased interest, useful strategies for improving diverse representation in higher learning. Given this important pathway to STEM fields, attention to equity in enrichment programs admissions is as important as the increasing focus on mitigating racial/ethnic disparities in undergraduate and graduate admissions.  Methods: In a retrospective cohort study at the University of Washington, we used descriptive and Chi-Square statistics to compare a hybrid competitive summer application program with stipend with an asynchronous first-come, first-served enrollment program in injury and violence prevention research. The three main outcomes were: 1) time to application, measured by number of days to apply/enroll after application or enrollment period start date, 2) percentage of application/enrollment period, measured by when application or enrollment occurred in relation to the total application or enrollment period, and 3) differences in Black, Hispanic, and Native American applicants and enrollees.  Results: In a study examining two injury and violence prevention programs, which reached educational institutions including Historically Black Colleges and Universities (HBCU) and Tribal Colleges: 1) Applicants were 9.6% and 6.4% Black (application vs enrollment programs; p<0.0001), 0.4% and 0% Native American to the application and enrollment programs, and 9.1% and 10.3% Hispanic (application vs enrollment programs; p=0.6), 2) Across all racial and ethnic groups, students applied later (last 15% percent of application period) in the competitive application program than to the first-come first-served enrollment program in which students enrolled throughout the enrollment period, and 3) Across both program types, there were racial and ethnic differences in time to application and enrollment start and completion. CONCLUSION: Findings show that free enrollment programs alone do not incentivize educational attainment for all groups and that application rolling admissions processes may not equally promote racial and ethnic diversity for all groups.

Jump performance and movement quality in 7- to 15-year-old competitive alpine skiers: a cross-sectional study.

INTRODUCTION: Injury rates in competitive alpine skiing are high. With current methods, identifying people at risk is expensive and thus often not feasible at the youth level. The aims of this study were (1) to describe the jump performance and movement quality of youth competitive alpine skiers according to age and sex, (2) to compare the jump distance among skiers of different sexes and movement quality grades, and (3) to assess the inter-rater grading reliability of the qualitative visual movement quality classification of such jumps and the agreement between live and video-based post-exercise grading. MATERIALS AND METHODS: This cross-sectional study is based on an anonymized dataset of 301 7- to 15-year-old competitive alpine skiers. The skiers performed two-legged forward triple jumps, whereby the jump distance was measured, and grades were assigned by experienced raters from the frontal and sagittal perspectives depending on the execution quality of the jumps. Furthermore, jumps were filmed and ultimately rated post-exercise. Differences in jump distance between various groups were assessed by multivariate analyses of variance (MANOVAs). Reliability was determined using Kendall's coefficient of concordance. RESULTS: The jump distance was significantly greater in U16 skiers than in U11 skiers of both sexes and in skiers with good execution quality than in those with reduced or poor execution quality. Overall, jump distance in U16 skiers significantly differed between female (5.37 m with 95% CI [5.21, 5.53]) and male skiers (5.90 m with 95%CI [5.69, 6.10]). Slightly better inter-rater grading reliability was observed for video-based post-exercise (strong agreement) ratings than for live ratings (moderate agreement). CONCLUSION: In competitive alpine skiers aged 7 to 15 years, jump performance increases with age, and around puberty, sex differences start to manifest. Our results highlight the importance of evaluating both jump distance and movement quality in youth skiers. To improve test-retest reliability, however, a video-based post-exercise evaluation is recommended.

In youth competitive alpine skiers, jump performance and movement quality matter, and both should be trained and tested.A qualitative assessment of movement quality while jumping by experts is a highly scalable and cost-effective approach; however, to ensure sufficient test-retest reliability, the assessment criteria need to be standardised and an additional video-based post-exercise assessment is recommended.