Building CapaCITY/É for sustainable transportation: protocol for an implementation science research program in healthy cities.

INTRODUCTION: Improving sustainable transportation options will help cities tackle growing challenges related to population health, congestion, climate change and inequity. Interventions supporting active transportation face many practical and political hurdles. Implementation science aims to understand how interventions or policies arise, how they can be translated to new contexts or scales and who benefits. Sustainable transportation interventions are complex, and existing implementation science frameworks may not be suitable. To apply and adapt implementation science for healthy cities, we have launched our mixed-methods research programme, CapaCITY/É. We aim to understand how, why and for whom sustainable transportation interventions are successful and when they are not. METHODS AND ANALYSIS: Across nine Canadian municipalities and the State of Victoria (Australia), our research will focus on two types of sustainable transportation interventions: all ages and abilities bicycle networks and motor vehicle speed management interventions. We will (1) document the implementation process and outcomes of both types of sustainable transportation interventions; (2) examine equity, health and mobility impacts of these interventions; (3) advance implementation science by developing a novel sustainable transportation implementation science framework and (4) develop tools for scaling up and scaling out sustainable transportation interventions. Training activities will develop interdisciplinary scholars and practitioners able to work at the nexus of academia and sustainable cities. ETHICS AND DISSEMINATION: This study received approval from the Simon Fraser University Office of Ethics Research (H22-03469). A Knowledge Mobilization Hub will coordinate dissemination of findings via a website; presentations to academic, community organisations and practitioner audiences; and through peer-reviewed articles.

Correction: Currie et al. Reality Check 2: The Cost-Effectiveness of Policy Disallowing Body Checking in Non-Elite 13- to 14-Year-Old Ice Hockey Players. Int. J. Environ. Res. Public Health 2021, 18, 6322.

There was an error in our original publication [...].

Youth Injury Knowledge and Beliefs following Neuromuscular Training Warm-up Implementation in Schools.

Neuromuscular training warm-up programs can reduce injury rates in youth sports, but they often have poor uptake and adherence. Delivering such programs in school physical education classes may provide greater public health benefit, particularly if they promote improved injury knowledge and prevention beliefs amongst students. The purpose of this secondary analysis of a large cluster-randomized controlled trial was to understand how students' (age 11-15 years) knowledge and beliefs change after exposure to an evidence-informed neuromuscular training warm-up program. Six schools delivered the program for a 12-week period in the initial study year (n=566) and two continued to use it in a subsequent "maintenance" year (n=255). Students completed a knowledge and beliefs questionnaire at baseline, 6-week, and 12-week timepoints. Knowledge scores ranged from 7/10 to 8/10 at all timepoints and students generally believed that injuries are preventable. On average, there was less than a one-point change in knowledge between timepoints and there was no change in the median belief scores. There were no meaningful differences between sexes, grades, or previous injury. These findings highlight that knowledge and beliefs are unlikely to change passively through program exposure. More active strategies are needed to improve injury prevention perceptions in this population.

Differences in injury and concussion rates in a cohort of Canadian female and male youth Rugby Union: a step towards targeted prevention strategies.

OBJECTIVE: To examine differences in match and training musculoskeletal injury and concussion rates and describe mechanisms of concussion while considering previous playing experience in female and male Canadian high school Rugby Union ('rugby') players. METHODS: A 2-year prospective cohort study was completed in a high school league (n=361 females, 421 player-seasons; n=429 males, 481 player-seasons) in Calgary, Canada over the 2018 and 2019 rugby playing seasons. Baseline testing was completed at the start of each season and injury surveillance and individual player participation through session attendance was documented to quantify individual-level player exposure hours. Injury incidence rates (IRs) and incidence rate ratios (IRRs) were calculated using Poisson regression, offset by player exposure hours and clustered by team. RESULTS: Overall match IR for females was 62% higher than males (overall IRR=1.62, 95% CI: 1.20 to 2.18) and the overall training IR was twice as high for females (overall IRR=2.15, 95% CI: 1.40 to 3.32). The female match concussion IR was 70% higher than the males (concussion IRR=1.70, 95% CI: 1.08 to 2.69). Females had a 75% greater tackle-related IR compared with males (IRR=1.75, 95% CI: 1.20 to 2.56). Additionally, female tacklers had a twofold greater rate of injury compared with male tacklers (IRR=2.17, 95% CI: 1.14 to 4.14). Previous playing experience was not associated with tackle-related injury or concussion IRs. CONCLUSION: The rate of injury and concussion was significantly higher in females within this Canadian high school cohort. These results emphasise the need for development, implementation and evaluation of female-specific injury and concussion prevention strategies to reduce injury and concussion in female youth rugby.

How to harness and improve on video analysis for youth rugby player safety: a narrative review.

Video analysis is a useful tool for injury surveillance in rugby union. There are few video analysis studies in the professional female game, with most studies published in the male elite/professional settings. Moreover, there is a sparsity of literature in youth rugby settings. The following narrative review outlines the strengths and limitations of the current video analysis literature for injury surveillance in youth rugby union, highlights the importance of video analysis for youth rugby player safety and welfare, and discusses recommendations for using video analysis to inform player safety in youth rugby.

Effectiveness of an injury prevention video on risky behaviours in youth snow sports: A randomized controlled trial.

Objectives: Ski and snowboard-related injuries are common among Canadian youth. Analyzing the role of risky behaviours that contribute to injury risk is essential for gaining an understanding of injury prevention opportunities. The objective was to determine if rates of risky behaviour seen at the ski hill were lower for children and adolescents exposed to an educational injury prevention video. Methods: This single-blinded cluster randomized controlled trial included students (ages 7-16) from 18 Calgary schools who were enrolled in novice levelled school-sanctioned ski and snowboard programs. Consenting schools were randomly assigned to the intervention or control. The control group followed standard preparation including watching a general ski hill orientation video that was created by the ski hill. The intervention group viewed the intervention video focussed on injury prevention. The Risky Behaviour and Actions Assessment Tool was used by blinded research assistants to observe and record students' risky behaviours at an Alberta ski hill. Results: In total, 407 observations estimated the rate of risky behaviour. The overall rate of risky behaviour was 23.31/100 person runs in the control group and 22.95/100 person runs in the intervention group. The most commonly observed risky behaviours in both groups were skiing too close to other skiers/snowboarders and near collision with an object/person. Conclusions: Both groups showed similar rates of risky behaviour and demonstrated the same most common type of behaviour. Practical applications: future work should focus on mitigating common risky behaviours.

Psychosocial Factors Associated With Time to Recovery After Concussion in Adolescent Ice Hockey Players.

OBJECTIVE: To investigate the association between psychosocial factors and physician clearance to return to play (RTP) in youth ice hockey players after sport-related concussion. DESIGN: Prospective cohort study, Safe to Play (2013-2018). SETTING: Youth hockey leagues in Alberta and British Columbia, Canada. PARTICIPANTS: Three hundred fifty-three ice hockey players (aged 11-18 years) who sustained a total of 397 physician-diagnosed concussions. INDEPENDENT VARIABLES: Psychosocial variables. MAIN OUTCOME MEASURES: Players and parents completed psychosocial questionnaires preinjury. Players with a suspected concussion were referred for a study physician visit, during which they completed the Sport Concussion Assessment Tool (SCAT3/SCAT5) and single question ratings of distress and expectations of recovery. Time to recovery (TTR) was measured as days between concussion and physician clearance to RTP. Accelerated failure time models estimated the association of psychosocial factors with TTR, summarized with time ratios (TRs). Covariates included age, sex, body checking policy, days from concussion to the initial physician visit, and symptom severity at the initial physician visit. RESULTS: Self-report of increased peer-related problems on the Strengths and Difficulties Questionnaire (TR, 1.10 [95% CI, 1.02-1.19]), higher ratings of distress about concussion outcomes by participants (TR, 1.06 [95% CI, 1.01-1.11]) and parents (TR, 1.05 [95% CI, 1.01-1.09]), and higher parent ratings of distress about their child's well-being at the time of injury (TR, 1.06 [95% CI, 1.02-1.09]) were associated with longer recovery. CONCLUSIONS: Greater pre-existing peer-related problems and acute distress about concussion outcomes and youth well-being predicted longer TTR. Treatment targeting these psychosocial factors after concussion may promote recovery.

Factors Associated With Concussion Rates in Youth Ice Hockey Players: Data From the Largest Longitudinal Cohort Study in Canadian Youth Ice Hockey.

OBJECTIVES: To examine factors associated with rates of game and practice-related concussion in youth ice hockey. DESIGN: Five-year prospective cohort (Safe2Play). SETTING: Community arenas (2013-2018). PARTICIPANTS: Four thousand eighteen male and 405 female ice hockey players (6584 player-seasons) participating in Under-13 (ages 11-12), Under-15 (ages 13-14), and Under-18 (ages 15-17) age groups. ASSESSMENT OF RISK FACTORS: Bodychecking policy, age group, year of play, level of play, previous injury in the previous year, lifetime concussion history, sex, player weight, and playing position. MAIN OUTCOME MEASUREMENTS: All game-related concussions were identified using validated injury surveillance methodology. Players with a suspected concussion were referred to a study sport medicine physician for diagnosis and management. Multilevel Poisson regression analysis including multiple imputation of missing covariates estimated incidence rate ratios (IRRs). MAIN RESULTS: A total of 554 game and 63 practice-related concussions were sustained over the 5 years. Female players (IRR Female/Male = 1.79; 95% CI: 1.26-2.53), playing in lower levels of play (IRR = 1.40; 95% CI: 1.10-1.77), and those with a previous injury (IRR = 1.46; 95% CI: 1.13, 1.88) or lifetime concussion history (IRR = 1.64; 95% CI: 1.34-2.00) had higher rates of game-related concussion. Policy disallowing bodychecking in games (IRR = 0.54; 95% CI: 0.40-0.72) and being a goaltender (IRR Goaltenders/Forwards = 0.57; 95% CI: 0.38-0.87) were protective against game-related concussion. Female sex was also associated with a higher practice-related concussion rate (IRR Female/Male = 2.63; 95% CI: 1.24-5.59). CONCLUSIONS: In the largest Canadian youth ice hockey longitudinal cohort to date, female players (despite policy disallowing bodychecking), players participating in lower levels of play, and those with an injury or concussion history had higher rates of concussion. Goalies and players in leagues that disallowed bodychecking had lower rates. Policy prohibiting bodychecking remains an effective concussion prevention strategy in youth ice hockey.

Traffic-Calming Measures and Road Traffic Collisions and Injuries: a Spatiotemporal Analysis.

Traffic-calming measures (TCMs) are physical modifications to the road network aimed at making the roads safer. Although studies have reported reductions in road crashes and injuries tied to the presence of TCMs, they have been criticized for their pre-post designs. This study aims to complement our knowledge of TCMs effectiveness by assessing their impact using a longitudinal design. The implementation of eight TCMs, including curb extensions and speed humps, was evaluated at the intersections and census tract levels in Montreal, Canada from 2012 to 2019. The primary outcome was fatal or serious collisions among all road users. Inference was performed using a Bayesian implementation of Conditional Poisson regression in which random effects were used to account for the spatiotemporal variation in collisions. TCMs were generally implemented on local roads, although most collisions occurred on arterial roads. Overall, there was weak evidence that TCMs were associated with study outcomes. However, subgroup analyses of intersections on local roads suggested a reduction in collision rates due to TCMs (median IRR: 0.31; 95% Credible Interval: 0.12 - 0.86). To improve road safety, effective counterparts of TCMs on arterial roads must be identified and implemented.

Blame attribution analysis of police motor vehicle collision reports involving child bicyclists.

BACKGROUND: Injuries resulting from collisions between a bicyclist and driver are preventable and have high economic, personal and societal costs. Studying the language choices used by police officers to describe factors responsible for child bicyclist-motor vehicle collisions may help shift prevention efforts away from vulnerable road users to motorists and the environment. The overall aim was to investigate how police officers attribute blame in child (≤18 years) bicycle-motor vehicle collision scenarios. METHODS: A document analysis approach was used to analyse Alberta Transportation police collision reports from Calgary and Edmonton (2016-2017). Collision reports were categorised by the research team according to perceived blame (child, driver, both, neither, unsure). Content analysis was then used to examine police officer language choices. A narrative thematic analysis of the individual, behavioural, structural and environmental factors leading to collision blame was then conducted. RESULTS: Of 171 police collision reports included, child bicyclists were perceived to be at fault in 78 reports (45.6%) and adult drivers were perceived at fault in 85 reports (49.7%). Child bicyclists were portrayed through language choices as being irresponsible and irrational, leading to interactions with drivers and collisions. Risk perception issues were also mentioned frequently in relation to poor decisions made by child bicyclists. Most police officer reports discussed road user behaviours, and children were frequently blamed for collisions. CONCLUSIONS: This work provides an opportunity to re-examine perceptions of factors related to motor vehicle and child bicyclist collisions with a view to prevention.

Is higher school neighbourhood Walk Score associated with greater child pedestrian safety near schools?

Walk Score is a common index used to estimate how suitable the built environment is for walking. Although Walk Score has been extensively validated as a measure of walkability and walking, there are limited studies examining whether commonly used constructs of walkability are associated with traffic safety in children. This study examined the association between Walk Score and child pedestrian injury controlling for observed walking exposure in school zones in Calgary, Toronto and Montreal, Canada. Results indicate that a higher Walk Score was associated with more child pedestrian injuries in all three cities, even after controlling for walking exposure. School travel planning should consider established individual pedestrian collision risk and individual factors rather than assuming a highly walkable environment is also a safe pedestrian environment.

Prevention strategies and modifiable risk factors for sport-related concussions and head impacts: a systematic review and meta-analysis.

OBJECTIVES: To evaluate prevention strategies, their unintended consequences and modifiable risk factors for sport-related concussion (SRC) and/or head impact risk. DESIGN: This systematic review and meta-analysis was registered on PROSPERO (CRD42019152982) and conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. DATA SOURCES: Eight databases (MEDLINE, CINAHL, APA PsycINFO, Cochrane (Systematic Review and Controlled Trails Registry), SPORTDiscus, EMBASE, ERIC0 were searched in October 2019 and updated in March 2022, and references searched from any identified systematic review. ELIGIBILITY CRITERIA: Study inclusion criteria were as follows: (1) original data human research studies, (2) investigated SRC or head impacts, (3) evaluated an SRC prevention intervention, unintended consequence or modifiable risk factor, (4) participants competing in any sport, (5) analytic study design, (6) systematic reviews and meta-analyses were included to identify original data manuscripts in reference search and (7) peer-reviewed. Exclusion criteria were as follows: (1) review articles, pre-experimental, ecological, case series or case studies and (2) not written in English. RESULTS: In total, 220 studies were eligible for inclusion and 192 studies were included in the results based on methodological criteria as assessed through the Scottish Intercollegiate Guidelines Network high ('++') or acceptable ('+') quality. Evidence was available examining protective gear (eg, helmets, headgear, mouthguards) (n=39), policy and rule changes (n=38), training strategies (n=34), SRC management strategies (n=12), unintended consequences (n=5) and modifiable risk factors (n=64). Meta-analyses demonstrated a protective effect of mouthguards in collision sports (incidence rate ratio, IRR 0.74; 95% CI 0.64 to 0.89). Policy disallowing bodychecking in child and adolescent ice hockey was associated with a 58% lower concussion rate compared with bodychecking leagues (IRR 0.42; 95% CI 0.33 to 0.53), and evidence supports no unintended injury consequences of policy disallowing bodychecking. In American football, strategies limiting contact in practices were associated with a 64% lower practice-related concussion rate (IRR 0.36; 95% CI 0.16 to 0.80). Some evidence also supports up to 60% lower concussion rates with implementation of a neuromuscular training warm-up programme in rugby. More research examining potentially modifiable risk factors (eg, neck strength, optimal tackle technique) are needed to inform concussion prevention strategies. CONCLUSIONS: Policy and rule modifications, personal protective equipment, and neuromuscular training strategies may help to prevent SRC. PROSPERO REGISTRATION NUMBER: CRD42019152982.

Road safety, health equity, and the built environment: perspectives of transport and injury prevention professionals in five Canadian municipalities.

BACKGROUND: Concerns regarding health equity (HE) and the built environment (BE) are well established in the Canadian urban context. Transport and injury prevention professionals across sectors, such as transportation and public health, are involved in designing and implementing BE interventions that enhance the safety of vulnerable road users (VRUs). Results from a larger study examining barriers and facilitators to BE change are used to illustrate how transport and injury prevention professionals perceive HE concerns in their work in five Canadian municipalities. Broadening our understanding of how HE influences the professional BE change context is crucial when advocating for modifications that enhance the safety of equity-deserving VRUs and groups who experience marginalization. METHODS: Interview and focus group data were gathered from transport and injury prevention professionals working in policy/decision-making, transport, police services, public health, non-profit organizations, schools/school boards, community associations, and private sectors across five Canadian urban municipalities: Vancouver, Calgary, Peel Region, Toronto, and Montréal. Data were analyzed using thematic analysis (TA) to illustrate how equity considerations were perceived and applied in participants' BE change work. RESULTS: The results of this study illustrate transport and injury prevention professionals' awareness of the varying needs of VRUs, as well as the inadequacies of current BEs in the Canadian urban context and consultation processes utilized to guide change. Participants emphasized the importance of equitable community consultation strategies, as well as specific BE changes that would support the health and safety of VRUs. Overall, the results highlight how HE concerns inform transport and injury prevention professionals' BE change work in the Canadian urban context. CONCLUSION: For professionals working in urban Canadian transport and injury prevention sectors HE concerns influenced their perspectives of the BE and BE change. These results illustrate a growing need for HE to guide BE change work and consultation processes. Further, these results contribute to ongoing efforts in the Canadian urban context to ensure that HE is at the forefront of BE policy change and decision-making, while promoting existing strategies to ensure that the BE, and related decision-making processes, are accessible and informed by a HE lens.

Injury Rates, Mechanisms, Risk Factors and Prevention Strategies in Youth Rugby Union: What's All the Ruck-Us About? A Systematic Review and Meta-analysis.

BACKGROUND: Rugby Union is a collision team sport played globally. Despite this, significant concerns have been raised regarding the sport's safety, particularly in youth players. Given this, a review of injury rates, risk factors and prevention strategies is required across different youth age groups as well as in males and females. OBJECTIVE: The objective of this systematic review (SR) and meta-analysis was to investigate injury and concussion rates, risk factors and primary prevention strategies in youth rugby. METHODS: To be included, studies were required to report either rates, risk factors or prevention strategies in youth rugby and to have a randomised controlled trial, quasi-experimental, cohort, case control, or ecological study design. Exclusion criteria included non-peer-reviewed grey literature, conference abstracts, case studies, previous systematic reviews and studies not written in English. Nine databases were searched. The full search strategy and list of sources are available and pre-registered on PROSPERO (Ref: CRD42020208343). Each study was assessed for risk of bias using the Downs and Black quality assessment tool. Meta-analyses were conducted using a DerSimonian Laird random effect model for each age group and sex. RESULTS: Sixty-nine studies were included in this SR. The match injury rates (using a 24-h time-loss definition) were 40.2/1000 match hours (95% CI 13.9-66.5) in males and 69.0/1000 match hours (95% CI 46.8-91.2) in females. Concussion rates were 6.2/1000 player-hours (95% CI 5.0-7.4) for males and 33.9/1000 player-hours (95% CI: 24.1-43.7) for females. The most common injury site was lower extremity (males) and the head/neck (females). The most common injury type was ligament sprain (males) and concussion (females). The tackle was the most common event associated with injury in matches (55% male, 71% females). Median time loss was 21 days for males and 17 days for females. Twenty-three risk factors were reported. The risk factors with the strongest evidence were higher levels of play and increasing age. Primary injury prevention strategies were the focus of only eight studies and included law changes (n = 2), equipment (n = 4), education (n = 1) and training (n = 1). The prevention strategy with the most promising evidence was neuromuscular training. The primary limitations included a broad range of injury definitions (n = 9) and rate denominators (n = 11) used, as well as a limited number of studies which could be included in the meta-analysis for females (n = 2). CONCLUSION: A focus on high-quality risk factor and primary prevention evaluation should be considered in future studies. Targeting primary prevention and stakeholder education remain key strategies in the prevention, recognition and management of injuries and concussions in youth rugby.

Between paradigms: Comparing experiences for adolescents treated at pediatric and adult trauma centres.

INTRODUCTION: Injured adolescents may be treated at pediatric trauma centres (PTCs) or adult trauma centres (ATCs). Patient and parent experiences are an integral component of high-quality health care and can influence patient clinical trajectory. Despite this knowledge, there is little research on differences between PTCs and ATCs with respect to patient and caregiver-reported experience. We sought to identify differences in patient and parent-reported experiences between the regional PTC and ATC using a recently developed Patient and Parent-Reported Experience Measure. METHODS: We prospectively enrolled patients (caregivers) aged 15-17 (inclusive), admitted to the local PTC and ATC for injury management (01/01/2020 - 31/05/2021) We provided a survey 8-weeks post-discharge to query acute care and follow-up experience. Patient and parent experiences were compared between the PTC and ATC using descriptive statistics, chi-square tests for categorical and independent t-tests for continuous variables. RESULTS: We identified 90 patients for inclusion (51 PTC, and 39 ATC). From this population, we had 77 surveys (32 patient and 35 caregiver) completed at the PTC, and 41 (20 patient and 21 caregiver) at the ATC. ATC patients tended to be more severely injured. We identified few differences in reported experience on the patient measure but identified lower ratings from caregivers of adolescents treated in ATCs for the domains of information and communication, follow-up care, and overall hospital scores. Patients and parents reported poorer family accommodation at the ATC. CONCLUSION: Patient experiences were similar between centres. However, caregivers report poorer experiences at the ATC in several domains. These differences are multifaceted, and may reflect differing patient volumes, effects of COVID-19, and healthcare paradigms. However, further work should target information and communication improvement in adult paradigms given its impact on other domains of care.

Physical Contact and Suspected Injury Rates in Female versus Male Youth Ice Hockey: A Video-Analysis Study.

OBJECTIVE: Canada's national winter sport of ice hockey has high youth participation; however, research surrounding female ice hockey is limited and the injury burden remains high. This study compared rates of head contact (HC), body checking (BC; high-intensity player-to-player contact), and suspected concussion between female and male youth ice hockey. DESIGN: Cross-sectional. SETTING: Game video-recordings captured in Calgary, Canada. PARTICIPANTS: Ten female (BC prohibited) and 10 male (BC permitted) U15 elite AA (13-14-year-old) game video-recordings collected in the 2021 to 22 seasons and 2020 to 21, respectively. ASSESSMENT OF RISK FACTORS: An analysis of player-to-player physical contact and injury mechanisms using video-analysis. MAIN OUTCOME MEASURES: Videos were analyzed in Dartfish video-analysis software and all physical contacts were coded based on validated criteria, including HCs (direct [HC1], indirect [HC2]), BC (levels 4-5 on a 5-point intensity scale), and video-identified suspected concussions. Univariate Poisson regression clustering by team-game offset by game-length (minutes) were used to estimate incidence rates and incidence rate ratios (IRR, 95% confidence intervals). RESULTS: The female game had a 13% lower rate of total physical contacts (IRR = 0.87, 0.79-0.96) and 70% lower rate of BC (IRR = 0.30, 0.23-0.39). There were however no differences in the rates of direct HC (IRR = 1.04, 0.77-1.42) or suspected concussion (IRR = 0.42, 0.12-1.42) between the cohorts. Although prohibited in the female game, only 5.4% of HC1s and 18.6% of BC resulted in a penalty. CONCLUSIONS: The rates of HC1s and suspected concussions were similar across youth ice hockey. BC rates were lower in the female game, yet still prevalent despite being prohibited.

Protective equipment in youth ice hockey: are mouthguards and helmet age relevant to concussion risk?

OBJECTIVES: To compare the incidence rates and odds of concussion between youth ice hockey players based on mouthguard use and helmet age. MATERIALS AND METHODS: Within a 5-year longitudinal cohort (2013/2014 to 2017/2018) of male and female ice hockey players (ages 11-18; n=3330 players) in Alberta (Canada), we analysed the relationship of equipment and concussion in both a prospective cohort and nested case (concussion) control (acute musculoskeletal injury) approach. The prospective cohort included baseline assessments documenting reported mouthguard use (yes/sometimes, no use), helmet age (newer/<2 years old, older/≥2 years old) and important covariables (weight, level of play, position of play, concussion history, body checking policy), with weekly player participation throughout the season. The nested case-control component used injury reports to document equipment (mouthguard use, helmet age) and other information (eg, mechanism and type of injury) for the injury event. Multivariable mixed effects negative binomial regression (prospective cohort, incidence rate ratios (IRRs)) and multivariable mixed effects logistic regression (nested case-control, odds ratios (OR)) examined the association between equipment and concussion. RESULTS: Players who reported wearing a mouthguard had a 28% lower concussion rate (IRR=0.72, 95% CI 0.56 to 0.93) and 57% lower odds of concussion (OR=0.43, 95% CI 0.27 to 0.70) compared with non-wearers. There were no associations in the concussion rate (IRR=0.94, 95% CI 0.75 to 1.15) and odds (OR=1.16, 95% CI 0.73 to 1.86) between newer and older helmets. CONCLUSIONS: Wearing a mouthguard was associated with a lower concussion rate and odds. Policy mandating use should be considered in youth ice hockey. More research is needed to identify other helmet characteristics (eg, quality, fit) that could lower concussion risk.

Can Referees Assess Head Contact Penalties Correctly in Canadian Youth Ice Hockey? A Video Analysis Study.

OBJECTIVE: To help address the high concussion burden in Canadian youth ice hockey, our primary objective was to examine the concurrent validity of youth ice hockey referees' ability to assess head contacts (HCs) and associated penalties using video analysis methods after implementation of the "zero tolerance for HC" policy by Hockey Canada. STUDY DESIGN: Cross-sectional study. PARTICIPANTS: Certified Level II-III referees in Alberta, Canada. INTERVENTION: A secured online survey with 60 videos (10 to 15 seconds) containing a player-to-player physical contact with or without a HC from elite U15 (ages 13 to 14) youth ice hockey games. OUTCOME MEASURES: Survey questions were completed by all referees for each video, including (1). 'Did you see a player-to-player contact?', (2). 'Should a penalty be assessed?', and if yes, (3). 'Which player, penalty type, and penalty intensity?' Referee assessments were compared with a consensus agreement from 2 national and member (top level) gold standard referees for concurrent validity through percent agreement and sensitivity/specificity measures. RESULTS: Complete-case analysis of 100 referees (131 recruited) showed an overall median agreement of 83.5% (sensitivity = 0.74; specificity = 0.69) with the gold standard. Agreement with the gold standard was highest for HC infractions [85.1% (sensitivity = 0.80; specificity = 0.69)], followed by HC penalty type (81.5%) and penalty intensity (53.7%). CONCLUSIONS: Concurrent validity through percent agreement was high (>80%) compared with the gold standard for identifying both HC and other infractions; however, it was moderate for penalty intensity. Although knowledge of identifying HCs and penalties in this survey was acceptable, this study suggests in-game factors (eg, game management and positioning) may be a primary limitation for HC enforcement.

High Sport Specialization Is Associated With More Musculoskeletal Injuries in Canadian High School Students.

OBJECTIVE: To describe levels of sport specialization in Canadian high school students and investigate whether sport specialization and/or sport participation volume is associated with the history of musculoskeletal injury and/or concussion. DESIGN: Cross-sectional study. SETTING: High schools, Alberta, Canada. PARTICIPANTS: High school students (14-19 years) participating in various sports. INDEPENDENT VARIABLES: Level of sport specialization (high, moderate, low) and sport participation volume (hours per week and months per year). MAIN OUTCOME MEASURES: Twelve-month injury history (musculoskeletal and concussion). RESULTS: Of the 1504 students who completed the survey, 31% were categorized as highly specialized (7.5% before the age of 12 years). Using multivariable, negative, binomial regression (adjusted for sex, age, total yearly training hours, and clustering by school), highly specialized students had a significantly higher musculoskeletal injury rate [incidence rate ratio (IRR) = 1.36, 95% confidence interval (CI), 1.07-1.73] but not lower extremity injury or concussion rate, compared with low specialization students. Participating in one sport for more than 8 months of the year significantly increased the musculoskeletal injury rate (IRR = 1.27, 95% CI, 1.02-1.58). Increased training hours significantly increased the musculoskeletal injury rate (IRR = 1.18, 95% CI, 1.13-1.25), lower extremity injury rate (IRR = 1.16, 95% CI, 1.09-1.24), and concussion rate (IRR = 1.31, 95% CI, 1.24-1.39). CONCLUSIONS: Approximately one-third of Canadian high school students playing sports were categorized as highly specialized. The musculoskeletal injury rate was higher for high sport specialization students compared with low sport specialization students. Musculoskeletal injuries and concussion were also more common in students who train more and spend greater than 8 months per year in one sport.

It Takes Two to Tango: High Rates of Injury and Concussion in Ball Carriers and Tacklers in High School Boys' Rugby.

OBJECTIVE: To examine injury and concussion rates, mechanisms, locations, and types of injury in Canadian high school male rugby. DESIGN: Prospective cohort study. SETTING: High school male rugby. PARTICIPANTS: A total of 429 high school players (2018: n = 225, 2019: n = 256) were recruited from 12 teams in 7 schools in Calgary, Canada. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Injury surveillance included baseline questionnaires, weekly exposure, and injury reports. Injuries included those requiring medical attention, resulted in time loss and/or inability to complete a session. Concussion was defined as per the fifth Consensus on Concussion in Sport, and all players with a suspected concussion were referred to a study sport medicine physician. RESULTS: A total of 134 injuries were captured, leading to an injury incidence rate (IR) of 57.9/1000 hours [95% confidence intervals (CIs): 45.4-73.8]. Median time loss was 6 days (range: 0-90). Injuries to the head were the most common (40%), followed by shoulder (12%) and ankle (10%). The concussion IR was 22.0/1000 hours (95% CIs: 15.9-30.4), which was the most common injury type (38%), followed by sprain (20%) and strain (15%). Sixty-five percent of injuries occurred in the tackle (ball carrier 35%, tackler 30%) and 76% of concussions (ball carrier 41%, tackler 35%). CONCLUSIONS: The rate of injury and concussion in Canadian youth high school male rugby is high, with tackle-related injuries and concussions the most common. Given this, there is a critical need for implementation of prevention strategies, in particular targeting concussion and the tackle event (eg, neuromuscular, tackle training, and law changes).