A 2D video-based assessment is associated with 3D biomechanical contributors to dynamic knee valgus in the coronal plane

Introduction

Adolescent athletes involved in sports that involve cutting and landing maneuvers have an increased risk of anterior cruciate ligament (ACL) tears, highlighting the importance of identifying risky movement patterns such as dynamic knee valgus (DKV). Qualitative movement screenings have explored two-dimensional (2D) scoring criteria for DKV, however, there remains limited data on the validity of these screening tools. Determining a 2D scoring criterion for DKV that closely aligns with three-dimensional (3D) biomechanical measures will allow for the identification of poor knee position in adolescent athletes on a broad scale. The purpose of this study was to establish a 2D scoring criterion that corresponds to 3D biomechanical measures of DKV.

Methods

A total of 41 adolescent female club volleyball athletes performed a three-task movement screen consisting of a single-leg squat (SLS), single-leg drop landing (SLDL), and double-leg vertical jump (DLVJ). A single rater scored 2D videos of each task using four criteria for poor knee position. A motion capture system was used to calculate 3D joint angles, including pelvic obliquity, hip adduction, knee abduction, ankle eversion, and foot progression angle. Receiver operating characteristic curves were created for each 2D scoring criterion to determine cut points for the presence of movement faults, and areas under the curve (AUC) were computed to describe the accuracy of each 2D criterion compared to 3D biomechanical data.

Results

3D measures indicated knee abduction angles between 2.4°-4.6° (SD 4.1°-4.3°) at the time point when the center of the knee joint was most medial during the three tasks. AUCs were between 0.62 and 0.93 across scoring items. The MEDIAL scoring item, defined as the knee joint positioned inside the medial border of the shoe, demonstrated the greatest association to components of DKV, with AUCs ranging from 0.67 to 0.93.

Conclusion

The MEDIAL scoring criterion demonstrated the best performance in distinguishing components of DKV, specifically pelvic obliquity, hip adduction, ankle eversion, and foot progression. Along with the previously published scoring definitions for trunk-specific risk factors, the authors suggest that the MEDIAL criterion may be the most indicative of DKV, given an association with 3D biomechanical risk factors.

Shoulder Check: Investigating Shoulder Injury Rates, Types, Severity, Mechanisms, and Risk Factors in Canadian Youth Ice Hockey

OBJECTIVE

To describe shoulder-related injury rates (IRs), types, severity, mechanisms, and risk factors in youth ice hockey players during games and practices.

DESIGN

Secondary analysis of data from a 5-year prospective cohort study, Safe-to-Play (2013-2018).

SETTING

Canadian youth ice hockey.

PARTICIPANTS

Overall, 6584 player-seasons (representing 4417 individual players) participated. During this period, 118 shoulder-related games and 12 practice injuries were reported.

ASSESSMENT OF RISK FACTORS

An exploratory multivariable mixed-effects Poisson regression model examined the risk factors of body checking policy, weight, biological sex, history of injury in the past 12 months, and level of play.

MAIN OUTCOME MEASURES

Injury surveillance data were collected from 2013 to 2018. Injury rates with 95% confidence interval (CI) were estimated using Poisson regression.

RESULTS

The shoulder IR was 0.35 injuries/1000 game-hours (95% CI, 0.24-0.49). Two-thirds of game injuries (n = 80, 70%) resulted in >8 days of time-loss, and more than one-third (n = 44, 39%) resulted in >28 days of time-loss. An 83% lower rate of shoulder injury was associated with policy prohibiting body checking compared with leagues allowing body checking (incidence rate ratio [IRR], 0.17; 95% CI, 0.09-0.33). A higher shoulder IR was observed for those who reported any injury in the last 12-months compared with those with no history (IRR, 2.00; 95% CI, 1.33-3.01).

CONCLUSIONS

Most shoulder injuries resulted in more than 1 week of time-loss. Risk factors for shoulder injury included participation in a body-checking league and recent history of injury. Further study of prevention strategies specific to the shoulder may merit further consideration in ice hockey.

Preseason Measures of Cervical Spine Function, Vestibulo-Ocular Reflex, Dynamic Balance, and Divided Attention in Youth Ice Hockey Players

OBJECTIVES: Report typical scores and examine preseason cervical spine, vestibulo-ocular reflex, dynamic balance, and divided attention measures in competitive youth ice hockey players aged 10 to 18 years with and without a previous concussion history. DESIGN: Cross-sectional secondary analysis. METHODS: The exposure of interest was self-reported history of concussion. The main outcomes were cervical spine measures (Cervical Flexor Endurance [CFE; seconds], Cervical Flexion-Rotation Test [normal/abnormal], Anterolateral Cervical Spine Strength [kilograms], Head Perturbation Test (/8), and Joint Position Error [JPE; centimeters]), vestibulo-ocular reflex (Dynamic Visual Acuity [logMAR], Head Thrust Test [Positive/Negative]), dynamic balance (Functional Gait Assessment [/30]) and divided attention (Walking While Talking Test [seconds]). Multivariable linear or logistic regression, adjusted for age-group, sex, level of play, and clustered by team, were used to assess potential differences by concussion history. RESULTS: We included data from 2311 participants in this study (87.2% male, 12.8% female, 39.0% reported a previous concussion). No differences by concussion history were found across any of the measures (P values range: 0.17-0.99). Measures of cervical spine function and divided attention differed by age group (eg, Median Left Anterolateral Cervical Spine Strength [kilograms] for males: U13 = 7.46, U15 = 9.10, U18 = 9.67). CONCLUSION: Clinical outcomes scores in youth ice hockey players did not differ by concussion history. Performance on cervical spine strength, CFE, and JPE test outcomes may improve with age, highlighting the importance of developmental considerations when interpreting test scores. J Orthop Sports Phys Ther 2024;54(3):1-11. Epub 30 November 2023. doi:10.2519/jospt.2023.11958.

One-Year Injury History and Safe Dance Practices Among Female Highland Dancers in Canada

AIMS

Over 8,650 Highland dancers registered to compete in Royal Scottish Official Board of Highland Dancing events worldwide in 2019. While the burden of dance-related injuries is high among dancers, there are few studies examining Highland dance. The purpose of this study was to describe the prevalence of self-reported 1-year injury history and safe dance practices among female Highland dancers.

METHODS

Sixty-five female Canadian Highland dancers (median age 18; range 14-47) completed an anonymous online survey at the beginning of the 2019 championship season. Demographics (i.e., age, body mass index), exposure (e.g., months/year dancing), safe dance practices (e.g., environmental, physical, psychological), and 1-year injury history (i.e., yes/no) were self-reported. Three definitions of dance-related injury were used: 1) time-loss (missed ≥1 class, practice, performance, and/or competition); 2) medical attention (requiring professional medical care); and 3) any physical complaint that affected full participation.

RESULTS

Most participants were training at the elite standard/premier level (86%, 95%CI 75-93) and for ≥8 months/year (83%, 95%CI 75-93). The proportion of dancers reporting at least one physical complaint in the previous 1 year was 71% (95%CI 58-81). Sixty percent (95%CI 47-71) of dancers reported ≥1 medical attention and/or time-loss injury. All participants reported warming up regularly, with 59% (95%CI 46-70) participating in regular cool-downs.

CONCLUSION

The prevalence of 1-year injury history among female Highland dancers is high. Education on the benefits of safe dance practice for Highland dancers may be useful. Prospective cohort studies are needed to understand the dynamic nature of dance injuries across a full competitive season.

Validity and Reliability of the Pre-Adolescent Dance Injury and Participation Questionnaire (PADIP-Q)

INTRODUCTION

Dancers generally begin training in a variety of styles at a young age. Across ages and levels of participation, dancers are at high risk for injury. Most available injury surveillance tools, however, have been developed for adult populations. Valid, reliable tools that monitor injury and exposure of pre-adolescent dance populations are limited. Therefore, the purpose of this study was to determine the validity and reliability of a dance injury and participation questionnaire specifically for pre-adolescent private studio dancers.

METHODS

Four stages of validity and reliability testing assessed a novel questionnaire: initial design based on previous literature, expert panel review, cognitive interviews, and test-retest reliability. The target population was 8 to 12-year-olds who participate in at least 1 class/week at a private studio. Feedback from a panel review and cognitive interviews was incorporated. Test-retest analyses included Cohen's kappa coefficients and percent agreement for categorical variables, and intraclass correlation coefficients [ICCs (3,1)], absolute mean difference (md) and Pearson's correlation coefficients (r) for numerical data.

RESULTS

The final questionnaire was comprised of 4 sections: demographics, dance training history, current dance participation (previous 1-year and 4-months), and dance-related injury history (previous 1-year and 4-months). Items with categorical responses estimated kappa coefficients from 0.32 to 1.00, and percent agreement between 81% and 100%. For items with numeric responses, ICC estimates ranged between .14 and 1.00, r values between .14 and 1.00, and the largest absolute md was 0.46. The 4-month recall sections revealed higher agreement than the 1-year sections.

CONCLUSION

This valid pre-adolescent dance injury and participation questionnaire demonstrates good to excellent reliability across all items. To support participant completions, assistance from a parent/guardian is suggested. To move dance epidemiology research forward among private studio dancers aged 8 to 12 years, employment of this questionnaire is therefore recommended.

Academic Accommodations for Middle and High School Students Following a Concussion: Perspectives of Teachers and School Administrators

BACKGROUND

An estimated 1 in 5 adolescents have sustained a concussion in North America. Teachers and school administrators are responsible for implementing academic accommodations and other supports for optimal return to learn following a concussion. The primary objective of this study was to describe the prevalence and feasibility of providing academic accommodations to students following concussion from the perspectives of middle and high school teachers and school administrators.

METHODS

A cross-sectional survey was administered to teachers and school administrators (grades 7-12) across Canada online via REDCap. Participants were recruited via word-of-mouth and social media sampling. Survey responses were analyzed descriptively using proportions.

RESULTS

The survey was completed by 180 educators (138 teachers and 41 school administrators), of whom 86% had previously provided academic accommodations to students following concussion, and 96% agreed that students should have access to accommodations following concussion. Some accommodations (eg, breaks, extra time) were provided more often and were more feasible to provide than others (eg, no new learning, reduced bright light). Educators reported limited preparation time and limited school personnel support to assist students following concussion.

IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY

The most feasible accommodations should be prioritized, ensuring students are supported within the school environment.

CONCLUSIONS

Teachers and school administrators confirmed the importance of providing accommodations to students following concussion.

Development of a tailored concussion education program for athletes: a pragmatic multimethods design and integrated knowledge translation approach from needs assessment to design

OBJECTIVES

To understand Canadian university athletic programme concussion management needs, and to describe development and content of a tailored online concussion education tool for Canadian university/college athletes.

DESIGN

An integrated knowledge translation multiphased, multimethods approach was used. Phases included a needs assessment survey with university representatives and athletes, content selection, mapping behavioural goals to evidenced-based behaviour change techniques, script/storyboard development, engagement interviews with university athletes and tool development using user-centred design techniques.

SETTING

Canadian U SPORTS universities (n=56).

PARTICIPANTS

Overall, 64 university representatives (eg, administrators, clinicians) and 27 varsity athletes (52% male, 48% female) completed the needs assessment survey. Five athletes participated in engagement interviews.

OUTCOME MEASURES

Surveys assessed previous athlete concussion education, recommendations for concussion topics and tool design, concussion management challenges and interest in implementing a new course.

RESULTS

Institutions used a median (Med) of two (range 1-5) approaches when educating athletes about concussion. Common approaches were classroom-style education (50%), online training (41%) and informational handouts (39%). University representatives rated most important topics as: (1) what is a concussion, (2) how to recognise a concussion and (3) how to report a concussion (Medall=4.8/5). Athletes felt symptom recognition (96%) and effects on the brain (85%) were most important. The majority of athletes preferred learning via computer (81%) and preferred to learn alone (48%) versus group learning (7%). The final resource was designed to influence four behaviours: (1) report symptoms, (2) seek care, (3) encourage teammates to report symptoms and (4) support teammates through concussion recovery. Examples of behaviour change techniques included: knowledge/skills, problem-solving scenarios, verbal persuasion and social comparison. Athletes are guided through different interactions (eg, videos, flip cards, scenarios, testimonials) to maximise engagement (material review takes ~30 min).

CONCLUSIONS

The Concussion Awareness Training Tool for athletes is the first Canadian education tool designed to address the needs of Canadian university/college athletes.

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.

Unravelling the web: Experiences of adolescents returning to school following a concussion

One in five adolescents will sustain a concussion in their lifetime. A concussion may result in symptoms that affect an adolescent's ability to attend school and engage in learning tasks. This study was guided by interpretivism. We conducted one-on-one semi-structured interviews to explore the perspectives of 20 adolescents (ages 14-18) returning to school after a concussion. Interviews were coded inductively and analyzed using reflexive thematic analysis. Five interconnected themes emerged with returning to school and accessing school supports: (1) concussion symptoms affected adolescents' schoolwork; (2) access to academic accommodations eased adolescents' return to school; (3) having supportive and understanding friends, family, and teachers facilitated adolescents' return to school; (4) communication amongst school stakeholders was desired, but often lacking; and (5) feeling anxious, frustrated, and sad with the return to school process. Adolescents' experiences were multifaceted and many factors contributed to their return to school experiences. Our findings can inform our understanding of the experiences of adolescents returning to school following concussion and can inform the development of concussion management supports at schools.

Health care impact of implementing a clinical pathway for acute care of pediatric concussion: a stepped wedge, cluster randomised trial

OBJECTIVES

To test the effects of actively implementing a clinical pathway for acute care of pediatric concussion on health care utilization and costs.

METHODS

Stepped wedge, cluster randomized trial of a clinical pathway, conducted in 5 emergency departments (ED) in Alberta, Canada from February 1 to November 30, 2019. The clinical pathway emphasized standardized assessment of risk for persistent symptoms, provision of consistent information to patients and families, and referral for outpatient follow-up. De-identified administrative data measured 6 outcomes: ED return visits; outpatient follow-up visits; length of ED stay, including total time, time from triage to physician initial assessment, and time from physician initial assessment to disposition; and total physician claims in an episode of care.

RESULTS

A total of 2878 unique patients (1164 female, 1713 male) aged 5-17 years (median 11.00, IQR 8, 14) met case criteria. They completed 3009 visits to the 5 sites and 781 follow-up visits to outpatient care, constituting 2910 episodes of care. Implementation did not alter the likelihood of an ED return visit (OR 0.77, 95% CI 0.39, 1.52), but increased the likelihood of outpatient follow-up visits (OR 1.84, 95% CI 1.19, 2.85). Total length of ED stay was unchanged, but time from physician initial assessment to disposition decreased significantly (mean change - 23.76 min, 95% CI - 37.99, - 9.52). Total physician claims increased significantly at only 1 of 5 sites.

CONCLUSIONS

Implementation of a clinical pathway in the ED increased outpatient follow-up and reduced the time from physician initial assessment to disposition, without increasing physician costs. Implementation of a clinical pathway can align acute care of pediatric concussion more closely with existing clinical practice guidelines while making care more efficient.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05095012.

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.

Amsterdam 2022 process: A summary of the methodology for the Amsterdam International Consensus on Concussion in Sport

The purpose of this paper is to summarise the consensus methodology that was used to inform the International Consensus Statement on Concussion in Sport (Amsterdam 2022). Building on a Delphi process to inform the questions and outcomes from the 5th International Conference on Concussion in Sport, the Scientific Committee identified key questions, the answers to which would help encapsulate the current science in sport-related concussion and help guide clinical practice. Over 3½ years, delayed by 2 years due to the pandemic, author groups conducted systematic reviews on each selected topic. The 6th International Conference on Concussion in Sport was held in Amsterdam (27-30 October 2022) and consisted of 2 days of systematic review presentations, panel discussions, question and answer engagement with the 600 attendees, and abstract presentations. This was followed by a closed third day of consensus deliberations by an expert panel of 29 with observers in attendance. The fourth day, also closed, was dedicated to a workshop to discuss and refine the sports concussion tools (Concussion Recognition Tool 6 (CRT6), Sport Concussion Assessment Tool 6 (SCAT6), Child SCAT6, Sport Concussion Office Assessment Tool 6 (SCOAT6) and Child SCOAT6). We include a summary of recommendations for methodological improvements for future research that grew out of the systematic reviews.

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).

Injuries in Canadian high school boys’ collision sports: insights across football, ice hockey, lacrosse, and rugby

Background

Collision sport participation rates among high school youth in Canada are high. While participation is beneficial for physical and mental well-being, the rates of injury in these sports are high.

Aims

This study aims to compare injury rates and profiles across four common youth collision sports (ice hockey, tackle football, lacrosse, rugby).

Methods

Data from a cross-sectional questionnaire of 2029 high school youth were used to identify male collision sport participants to be included in this secondary analysis (n = 360).

Results

Of the 2029 students who completed the questionnaire, 360 participated in collision-based sports [Ages: 14 (5%), 15 (41%), 16 (25%), 17 (26%), 18 (3%)]. The rates of injury ranged from 12.7 injuries/100 participants/year (rugby) to 33.1 injuries/100 participants/year (ice hockey). Concussion rates ranged from 12.4 (football) to 15.8 (ice hockey) concussions/100 participants/year. Similarities existed in the profile of injuries between sports, with most injuries occurring due to contact with another player (range 57.0% to 87.5%). Injuries to the head (33.3%), wrist/hand (16.0%), shoulder (12.8%), and knee (12.0%) were the most prevalent injury type. Substantial differences in previous playing experience existed between sports.

Discussion

The high rate of injury and concussion reported across each of these sports highlights the need for the introduction of primary prevention strategies in these sports aimed to reduce the risk of injury.

Concussions and Injuries in Sledge Hockey: Grassroots to Elite Participation

OBJECTIVE

To examine injury (including concussion) rates, location, type, mechanisms, and risk factors in sledge hockey players.

DESIGN

Cross-sectional survey.

SETTING

Sledge hockey players, worldwide, across all levels of play.

PARTICIPANTS

Sledge hockey players (ages ≥14 years) who played in the 2019 to 2020 season were recruited through email, social media, and word of mouth communication.

ASSESSMENT OF RISK FACTORS

Participant characteristics (eg, age, sex, disability) were examined as potential injury risk factors.

MAIN OUTCOME MEASURES

Injury rates (IR) and incidence rate ratios (IRR) examining potential risk factors were reported based on univariate Poisson regression analyses. Injury proportions by type, location, and mechanism were described.

RESULTS

Ninety-two players initiated the survey, and 77 (83.7%) provided some injury information. Forty-seven injuries included 16 concussions in 9 of 77 players (11.7%) and 31 non-concussion injuries in 20 of 77 players (26.0%) were reported. The overall IR was 13.2 injuries/1000 athlete-exposures [95% confidence interval (CI); 9.6-17.6]. The game IR (28.4 injuries/1000 game-exposures, 95% CI; 18.6-41.7) was higher than practice IR (4.4 injuries/1000 practice-exposures, 95% CI; 2.2-7.9) (IRR = 6.5, 95% CI; 3.1-14.5). The most common injury locations were the head (34.0%), wrist/hand (14.8%), and shoulder (10.6%). The most common significant injury types were concussion (36.2%) and bone fracture (8.5%). Body checking was the primary mechanism for injuries caused by contact with another player (42.1%) Age, sex, disability, and level of play were not found as injury risk factors.

CONCLUSIONS

Concussions and upper extremity injuries were the most common sledge hockey injuries reported, with body checking being the most common mechanism. This research will inform development of prevention strategies in sledge hockey.

Concurrent Validity of Movement Screening Criteria Designed to Identify Injury Risk Factors in Adolescent Female Volleyball Players

Anterior cruciate ligament (ACL) injuries in female adolescent athletes occur at disproportionately high levels compared to their male counterparts. However, limited prospective data exist on the validity of low-cost screening tools that can proactively identify ACL injury risk, specifically for female athletes. The purpose of this study was to assess the concurrent validity of a three-task injury risk factor assessment by comparing visually derived outcome scores from two-dimensional (2D) video data with dichotomized three-dimensional (3D) biomechanical variables collected using motion capture technology. A total of 41 female club volleyball athletes (14.7 ± 1.4 years) were tested and asked to perform three tasks: double-leg vertical jump (DLVJ), single-leg squat (SLS), and single-leg drop landing (SLDL). One rater was trained on the scoring criteria for the 2D data and independently scored one forward-facing and one side-facing video for each task. Risk factors identified included poor knee position, lateral trunk lean, and excessive trunk flexion/extension. In addition, 3D joint angles were calculated for the trunk and knee in the sagittal and frontal planes and converted to dichotomous variables based on biomechanical thresholds of injury risk. For comparison of 2D and 3D outcomes, percent agreement and Cohen's kappa were calculated for each risk factor individually. Overall, 2D scores were found to exhibit moderate to excellent percent agreement with 3D outcomes for trunk position (69.1–97.1%). Specifically, ipsilateral trunk lean during single-leg tasks exhibited the highest agreement (85.3–88.2%) with moderate reliability (κ = 0.452–0.465). In addition, moderate to substantial reliability was found for trunk flexion during double-leg tasks (κ = 0.521–0.653); however, an evaluation of single-leg tasks resulted in only fair reliability (κ = 0.354). Furthermore, 2D scores were not successful in identifying poor knee position as percent agreement fell below 50% for both the single-leg tasks and averaged 60% agreement across both the phases of the DLVJ. Kappa coefficients further emphasized these trends indicating no to slight concurrent validity (κ = −0.047–0.167) across tasks. Overall, these findings emphasize the potential for valid, low-cost screening tools that can identify high-risk movement patterns. Further study is needed to develop improved assessment guidelines that may be employed through visual assessment in sports environments.

Bodychecking experience and rates of injury among ice hockey players aged 15-17 years

BACKGROUND

Although high rates of injury occur in youth ice hockey, disagreements exist about the risks and benefits of permitting bodychecking. We sought to evaluate associations between experience with bodychecking and rates of injury and concussion among ice hockey players aged 15-17 years.

METHODS

We obtained data from a prospective cohort study of ice hockey players aged 15-17 years in Alberta who played in leagues that permitted bodychecking. We collected data over 3 seasons of play (2015/16-2017/18). We compared players based on experience with bodychecking (≤ 2 v. ≥ 3 yr), estimated using local and national bodychecking policy and region of play. We used validated methodology of ice hockey injury surveillance to identify all injuries related to ice hockey games and defined concussions according to the Consensus Statement on Concussion in Sport.

RESULTS

We included 941 players who contributed to 1168 player-seasons, with 205 players participating in more than 1 season. Compared with players with 2 years or less of bodychecking experience, those with 3 or more years of experience had higher rates of all injury (adjusted incidence rate ratio [IRR] 2.55, 95% confidence interval [CI] 1.57-4.14), injury with more than 7 days of time loss (adjusted IRR 2.65, 95% CI 1.50-4.68) and concussion (adjusted IRR 2.69, 95% CI 1.34-5.42).

INTERPRETATION

Among ice hockey players aged 15-17 years who participated in leagues permitting bodychecking, more experience with bodychecking did not protect against injury. This provides further support for removing bodychecking from youth ice hockey.

Feasibility and Reliability of a Novel Game-Based Test of Neurological Function in Youth: The Equilibrium Test Battery

Background

An estimated 11% of Canadian adolescents will sustain a sport-related concussion each year. However, diagnostic tools to detect and monitor concussive outcomes are limited.

Purpose

To evaluate the feasibility and test-retest reliability of the Highmark Interactive Equilibrium (HIEQ) test battery in uninjured adolescents.

Study Design

Observational study with repeated measurements.

Methods

Participants completed the HIEQ test battery, a game-based platform on an iPad application, that assesses balance, cognitive function, and visual function, for up to 15 consecutive school days in a group classroom setting. Feasibility for use of the HIEQ was evaluated by (1) recruitment rates; (2) retention rates; (3) test completion without assistance; and (4) adverse events. Test-retest reliability was examined using Bland Altman 95% limits of agreement and intraclass correlation coefficients comparing the first and second and second and third obtained scores. Reliability across multiple baseline assessments was also analyzed using intraclass correlations for the second to sixth and seventh to eleventh obtained scores.

Results

Fifty-five uninjured high school students (31 females and 24 males, mean age = 16.24 [1.09]) from three high schools participated in the study. Three participants (5%) completed all 15 days of testing, and 73% completed at least 10 of 15 test days. No adverse events were reported. Although the test was feasible, all subtests showed wide limits of agreement from first to second and from second to third testing occasions. Results indicate poor-to-moderate reliability (<0.50 to 0.75) across those intervals, as well as across the second to sixth and seventh to eleventh testing occasions.

Conclusion

The HIEQ is feasible in high school students; however, performance was characterized by wide limits of agreement and poor-to-moderate reliability across test occasions. Future evaluation of the HIEQ in visual and auditory distraction free individual testing settings is warranted.

Level of Evidence

Level 3.

Influence of antibiotics given during labour and birth on body mass index z scores in children in the All Our Families pregnancy cohort

BACKGROUND/OBJECTIVES

Little is known about obesity risk associated with intrapartum antibiotic prophylaxis (IAP). Our objective was to determine if maternal antibiotic exposure during birth is associated with child body mass index (BMI) z scores in the first 3 years of life.

METHODS

In 2008 to 2010, 3388 pregnant women were recruited to the All Our Families study. Here, we included women with available data from obstetrical records on antibiotic use during birth (n = 1303) and children with at least one valid BMI z score (final sample n = 1262). The primary outcome was infant BMI z score at 1, 2 and 3 years of age.

RESULTS

IAP occurred in 432 of 1262 women. Children exposed to IAP had significantly higher mean [standard error (SE)] BMI z scores (1.071 [0.087] unit) at 1 year of age compared to non-exposed infants (0.744 [0.064] unit). Although the association was no longer significant after adjustment for confounding factors in the growth trajectory model, IAP resulted in a 0.255 unit increase in BMI z score at 1 year of age. Differences in BMI z score between exposed and non-exposed at baseline (year 1) only remained significant in sensitivity analysis.

CONCLUSION

The potential association between maternal IAP and increased infant BMI z score at 1 year of age should be confirmed in other cohorts and warrants investigation of interventions to mitigate this possible risk.

High Injury and Concussion Rates in Female Youth Team Sport: An Opportunity for Prevention

The aim of this study was to investigate sport-related injury rates, types, locations, and mechanisms in female youth team sports.This was a secondary analysis of a cross-sectional study. An anonymous online survey was administered to high school students (ages 14-19) in Canada. The survey included questions regarding demographic information, sport participation and self-reported injuries sustained in the past year. Results were analyzed for girls who reported playing a top ten team sports for female participation. For girls participating in team sports, the overall injury rate was 55.5 injuries/100 participants/year. The rate of at least one concussion was 9.4 concussions/100 participants/year. Injury and concussion rates were highest in ringette (Injury rate=42.9 injuries/100 participants/year, Concussion rate=19.0 concussions/100 participants/year) and rugby (Injury rate=40.0, Concussion rate=15.3). The top three most serious injury locations were the knee (24.7%), ankle (21.6%) and head (16.1%). The most common injury types were joint/ligament sprain (26.71%), fracture (13.0%) and concussion (11.8%). Contact mechanisms accounted for 73.4% of all serious injuries reported in girls team sports.Team sport injury rates are high in female youth team sports. Specific consideration of sport-specific injury rates, types and mechanisms in girls' team sports will inform development and evaluation of targeted sport-specific prevention strategies.

Sport participation and injury rates in high school students: A Canadian survey of 2029 adolescents

INTRODUCTION

The objective of this study is to examine sport and recreational (S&R) activity participation and injury rates (IR) in high school students (ages 14-19).

METHODS

High school students (N = 24 schools, n = 2,029; 958 male, 1,048 female, 23 identified 'other' or missing; ages 14-19) in Alberta completed a web-based survey during class (October 2018-March 2019). Students identified their top three sports for participation in the past year. Primary outcome measures included IR for (a) any S&R-related injury, (b) most serious S&R-related injury resulting in medical attention, and (c) most serious injury resulting in restriction from S&R for at least one day.

RESULTS

In total, 1763/2029 (86.89%) respondents [861/958 (89.87%) male, 886/1048 (84.54%) female, 16/23 (69.57%) identifying as 'other' or missing] participated in an S&R activity in the past year. Top sports for male participation were basketball (33.08%; 95% CI 27.67-39.00), ice hockey (20.46%; 95% CI 14.87-27.47), and soccer (19.42%; 95% CI 15.67-23.80). Top sports for female participation were dance (22.52%; 95% CI 17.98-27.82), basketball (18.32%; 95% CI 14.32-23.14), and badminton (17.84%; 95% CI 13.35-23.43). Of the 1,971 students completing the S&R injury question, 889 reported at least one injury during the past year [(IR = 45.10 injuries/100 students/year (95% CI 39.72-50.61)]. The medical attention IR was 29.09 injuries/100 students/year (95% CI 24.49-34.17) and time loss IR was 36.00 injuries/100 students/year (95% CI 30.47-41.93).

CONCLUSIONS

High school student S&R IRs are high with 29% of adolescents reporting at least one medical attention injury within the past year. Injury prevention strategies targeting youth are necessary. Practical Application: Participation in S&R activities has multiple physical, psychological, and health benefits for adolescents, but some S&R activities also have greater risks of injury. This study informs the next sports to target for implementation of optimal prospective surveillance and injury prevention strategies among high school aged students.

Reality Check 2: The Cost-Effectiveness of Policy Disallowing Body Checking in Non-Elite 13- to 14-Year-Old Ice Hockey Players

Sport-related injuries are the leading cause of injury in youth and are costly to the healthcare system. When body checking is disallowed in non-elite levels of Bantam (ages 13–14 years) ice hockey, the injury rate is reduced, but the impact on costs is unknown. This study compared rates of game injuries and costs among non-elite Bantam ice hockey leagues that disallow body checking to those that did not. Methods: An economic evaluation was conducted alongside a prospective cohort study comparing 608 players from leagues where body checking was allowed in games (Calgary/Edmonton 2014–2015, Edmonton 2015–2016) with 396 players from leagues where it was not allowed in games (Vancouver, Kelowna 2014–2015, Calgary in 2015–2016). The effectiveness measure was rate of game injuries per 1000 player-hours. Costs were estimated based on associated healthcare use within the publicly funded healthcare system as well as privately paid healthcare costs. Probabilistic sensitivity analysis was conducted using bootstrapping. Results: Disallowing body checking reduced the rate of injuries by 4.32 per 1000 player-hours (95% CI −6.92, −1.56) and reduced public and total healthcare system costs by $1556 (95% CI −$2478, −$559) and $1577 (95% CI −$2629, −$500) per 1000 player-hours, respectively. These finding were robust in over 99% of iterations in sensitivity analyses in the public healthcare and the total healthcare system perspectives. There was no statistically significant difference in privately paid healthcare costs (−$65 per 1000 player-hours (95% CI −$220, $99)). Interpretation: Disallowing body checking in non-elite 13–14-year-old ice hockey nationally would prevent injuries and reduce public healthcare costs.

An Economic Evaluation of Disallowing Body Checking in 11- to 12-Year-Old Ice Hockey Leagues

Background:

After a national policy change in 2013 disallowing body checking in Pee Wee ice hockey games, the rate of injury was reduced by 50% in Alberta. However, the effect on associated health care costs has not been examined previously.

Hypothesis:

A national policy removing body checking in Pee Wee (ages 11-12 years) ice hockey games will reduce injury rates, as well as costs.

Study Design:

Cost-effectiveness analysis alongside cohort study.

Level of Evidence:

Level 3.

Methods:

A cost-effectiveness analysis was conducted alongside a cohort study comparing rates of game injuries in Pee Wee hockey games in Alberta in a season when body checking was allowed (2011-2012) with a season when it was disallowed after a national policy change (2013-2014). The effectiveness measure was the rate of game injuries per 1000 player-hours. Costs were estimated based on associated health care use from both the publicly funded health care system and privately paid health care cost perspectives. Probabilistic sensitivity analysis was conducted using bootstrapping.

Results:

Disallowing body checking significantly reduced the rate of game injuries (−2.21; 95% CI [−3.12, −1.31] injuries per 1000 player-hours). We found no statistically significant difference in public health care system (−$83; 95% CI [−$386, $220]) or private health care costs (−$70; 95% CI [−$198, $57]) per 1000 player-hours. The probability that the policy of disallowing body checking was dominant (with both fewer injuries and lower costs) from the perspective of the public health care system and privately paid health care was 78% and 92%, respectively.

Conclusion:

Given the significant reduction in injuries, combined with lower public health care system and private costs in the large majority of iterations in the probabilistic sensitivity analysis, our findings support the policy change disallowing body checking in ice hockey in 11- and 12-year-old ice hockey leagues.

Canadian High School Rugby Coaches Readiness for an Injury Prevention Strategy Implementation: Evaluating a Train-the-Coach Workshop

Background: Canadian rugby coach injury prevention beliefs and attitudes have not been studied, yet are key to informing injury prevention strategy implementation. Despite neuromuscular training (NMT) warm-up success in reducing injury, adoption of these programs is variable. Therefore, objectives of this study included (1) describing Canadian youth rugby coach injury prevention beliefs and attitudes and current warm-up practices and (2) evaluating intention to use a rugby-specific NMT warm-up.

Methods: High school rugby coaches completed a questionnaire before and after a rugby-specific NMT warm-up workshop. The pre-workshop questionnaire captured demographics, current warm-up practice, and NMT warm-up knowledge and use. Both questionnaires captured injury prevention beliefs, attitudes and behavioral intention.

Results: Forty-eight coaches participated in the workshops. Pre-workshop, 27% of coaches were aware of NMT warm-ups. Coaches primarily included aerobic and stretching components, while balance components were not common in their warm-ups over the past year. Additionally, 92% of coaches agreed to some extent they would “complete a rugby-specific warm-up program prior to every game and training session this season.” Post-workshop, 86% of coaches agreed to some extent that they would use the program in every rugby session. No differences were observed between pre- and post-workshop intention to implement the warm-up (p = 0.10).

Interpretation: This is the first study to examine current Canadian youth rugby coach warm-up practices and intention to use NMT warm-ups. Canadian rugby coach intention to use a rugby-specific NMT warm-up is high, providing ample opportunity to investigate the efficacy of a NMT warm-up in youth rugby.

Factors Associated With Clinical Recovery After Concussion in Youth Ice Hockey Players

Background:

The identification of factors associated with clinical recovery in youth after sports-related concussion could improve prognostication regarding return to play (RTP).

Purpose:

To assess factors associated with clinical recovery after concussion in youth ice hockey players.

Study Design:

Cohort study; Level of evidence, 2.

Methods:

Participants were part of a larger longitudinal cohort study (the Safe to Play study; N = 3353). Included were 376 ice hockey players (age range, 11-17 years) from teams in Calgary and Edmonton, Canada, with 425 physician-diagnosed ice hockey–related concussions over 5 seasons (2013-2018). Any player with a suspected concussion was referred to a sports medicine physician for diagnosis, and a Sport Concussion Assessment Tool (SCAT) form was completed. Time to clinical recovery was based on time between concussion and physician clearance to RTP. Two accelerated failure time models were used to estimate days to RTP clearance: model 1 considered symptom severity according to the SCAT3/SCAT5 symptom evaluation score (range, 0-132 points), and model 2 considered responses to individual symptom evaluation items (eg, headache, neck pain, dizziness) of none/mild (0-2 points) versus moderate/severe (3-6 points). Other covariates were time to physician first visit (≤7 and >7 days), age group (11-12, 13-14, and 15-17 years), sex, league type (body checking and no body checking), tandem stance (modified Balance Error Scoring System result ≥4 errors out of 10), and number of previous concussions (0, 1, 2, and ≥3).

Results:

The complete case analysis (including players without missing covariates) included 329 players (366 diagnosed concussions). The median time to clinical recovery was 18 days. In model 1, longer time to first physician visit (>7 days) (time ratio [TR], 1.637 [95% confidence interval (CI), 1.331-1.996]) and greater symptom severity (TR, 1.016 [95% CI, 1.012-1.020]) were significant predictors of longer clinical recovery. In model 2, longer time to first physician visit (TR, 1.698 [95% CI, 1.399-2.062]), headache (moderate/severe) (TR, 1.319 [95% CI, 1.110-1.568]), and poorer tandem stance (TR, 1.249 [95% CI, 1.052-1.484]) were significant predictors of longer clinical recovery.

Conclusion:

Medical clearance to RTP was longer for players with >7 days to physician assessment, poorer tandem stance, greater symptom severity, and moderate/severe headache at first visit.

The Impact of COVID-19 on High School Student-Athlete Experiences with Physical Activity, Mental Health, and Social Connection

COVID-19 restrictions led to reduced levels of physical activity, increased screen usage, and declines in mental health in youth; however, in-depth understandings of the experiences of high school student-athletes have yet to be explored. To describe the experiences of the COVID-19 pandemic on student-athletes' physical activity, social connection, and mental health, 20 high school student-athletes living in Calgary, Alberta participated in semi-structured interviews, designed using phenomenography. Participants reported variations in physical activity, social connections, and mental health which were influenced by stay-at-home restrictions and weather. Access to resources, changes to routines, online classes, and social support all influenced engagement in physical activity. School and sports provided opportunities for in-person social connections, impacted by the onset of the pandemic. Participants reported their mental health was influenced by social connections, online classes, and physical activity. Findings from this study will inform the development of resources for high school student-athletes amidst COVID-19.

Active & Safe Central: using a mixed-methods design and the RE-AIM framework to evaluate a sport and recreational injury prevention resource for practitioners in Canada

OBJECTIVES

An online, evidence-based resource was created to support the development of sport and recreational injury prevention programmes. The resource, called Active & Safe Central (www.activesafe.ca), provides evidence-based information across the public health approach for a number of sport and recreational activities. The objective of this project was to evaluate the perceived usefulness of Active & Safe Central as an educational tool.

DESIGN

A mixed-methods study design, guided by the RE-AIM (reach, effectiveness, adoption, implementation and maintenance) framework, was used to evaluate Active & Safe Central.

SETTING

Data were collected using an online survey, available to all users of the site, and focus groups (n=2) that took place in Vancouver and Toronto, Canada.

PARTICIPANTS

Survey respondents (n=87) were recruited online, including parents, coaches, youth and adult athletes, and teachers. Focus group participants (n=16) were key stakeholders and end users, recruited from academia, local health sectors, sport and recreational organisations, and not-for-profit injury prevention organisations.

RESULTS

Post launch, there were 1712 users visiting the website 2306 times (sessions), with the majority representing new users, over returning users (87.5% and 12.5%, respectively). There were 6340 page visits, with the most popular pages including soccer, playgrounds and ice hockey. Active & Safe Central was reported as a credible source of evidence-based sport and recreational information and that the site would be recommended to others. Information collected from focus group participants was used to inform necessary adaptations to the online platform, including critical navigation issues, visualisations and interactivity. The major themes that emerged from focus group and survey data included increased awareness of injury prevention recommendations and that the recommendations would be used in one's own sporting activity and/or practice.

CONCLUSIONS

The results of the evaluation suggest the tool is a useful resource for sport and recreational injury information that has significant potential to impact prevention practice.

Internal Training Load Measures in Elite Adolescent Ballet Dancers

Training load has been identified as a risk factor for musculoskeletal injury in sport, but little is known about the effects of training load in dance. The purpose of this study was to describe adolescent dancers' internal training load (ITL) and compare objective and subjective measures of ITL using heart rate (HR) training impulse methods and session Rating of Perceived Exertion (sRPE), respectively. Fifteen female elite adolescent ballet dancers at a vocational dance school volunteered to participate in the study. Internal training load data using HR and sRPE were collected over 9 days of multiple technique classes at the midpoint of the dancers' training year. Heart rate data were quantified using Edwards' training impulse (ETRIMP) and Banister's training impulse (BTRIMP), and sRPE was estimated from the modified Borg 0 to 10 scale and class duration. Descriptive statistics (median [M], and interquartile range [IQR]) were determined in arbitrary units (AU), and were as follows for all classes combined: ETRIMP: M = 134 AU (IQR = 79 to 244 AU); BTRIMP: M = 67 AU (IQR = 38 to 109); sRPE: M = 407 AU (IQR = 287 to 836 AU). The association and agreement between objective and subjective ITL measures in ballet and pointe class was assessed using Spearman correlations (r_s) and adjusted Bland-Altman 95% limits of agreement (LOA), respectively, with alpha set at 0.05. A significant moderate positive correlation was found between ETRIMP and BTRIMP in pointe class (r_ρ = 0.8000, p = 0.0031). The mean difference (LOA) between ETRIMP and BTRIMP was 121 AU (33 to 210 AU) in ballet and 43 AU (-3 to 88 AU) in pointe. It is concluded that some, but not all, measures of ITL in elite adolescent ballet dancers are comparable. Additional research is needed to examine the utilization of ITL measures for evaluating dance-related injury risk, as well as the application of ITL to inform the development of effective injury prevention strategies for this high-risk population.

Association between concussion education and concussion knowledge, beliefs and behaviours among youth ice hockey parents and coaches: a cross-sectional study

OBJECTIVES

To examine the association between self-reported exposure to concussion education and knowledge, beliefs and self-reported behaviour among parents and coaches of youth ice hockey players.

DESIGN

Cross-sectional.

SETTING

Community ice hockey teams from Calgary and Edmonton, Alberta, Canada.

PARTICIPANTS

Parents and coaches of ice hockey players (ages 11-17, all divisions of play).

PRIMARY AND SECONDARY OUTCOME MEASURES

Participants completed a questionnaire developed and validated to measure concussion knowledge, beliefs and concussion management behaviour (ie, coaches removing athletes from play; parents taking children with suspected concussions to physicians) consistent with the Health Action Process Approach (HAPA). The questionnaire examined specific HAPA constructs (ie, risk perception, outcome expectancies, action self-efficacy, intention, action planning, maintenance self-efficacy, recovery self-efficacy) relevant to concussion management behaviour.

RESULTS

Participants included 786 parents (31.8% with coaching experience) and 10 non-parent coaches. Of the participants, 649 (82.6%) previously received concussion education. Based on a multivariable regression analysis adjusting for coaching experience, previous history of a child sustaining one or more concussions, first aid experience and cluster by team, exposure to concussion education was associated with a mean score difference of 1.36 (95% CI 0.68 to 2.03), p<0.0001, in the knowledge score. Exposure to concussion education was not significantly associated with any of the HAPA constructs based on Wilcoxon rank-sum tests.

CONCLUSION

Exposure to concussion education may be associated with small overall differences in concussion knowledge but may not be associated with significant differences in beliefs or intended behaviours related to concussion management among youth hockey parents and coaches.When providing education or recommendations for concussion education sources to coaches and parents, educational strategies grounded in behavioural change theory that specifically target the motivators of behavioural change should be considered.

Baseline Performance of High School Rugby Players on the Sport Concussion Assessment Tool 5

CONTEXT

Version 5 of the Sport Concussion Assessment Tool (SCAT5) was released in 2017 with an additional 10-word list option in the memory section and additional instructions for completing the symptom scale.

OBJECTIVE

To provide reference scores for high school rugby union players on the SCAT5, including immediate memory using the 10-word list, and examine how age, sex, and concussion history affected performance.

DESIGN

Cross-sectional study.

SETTING

Calgary, Alberta high schools.

PATIENTS OR OTHER PARTICIPANTS

High school rugby union players (ages 15-18 years) participating in a 2018 season cohort study (n = 380, males = 210, females = 170).

MAIN OUTCOME MEASURE(S)

Sport Concussion Assessment Tool 5 scores, including total number of symptoms (of 20), symptom severity (of 132), 10-word immediate memory (of 30), delayed memory (of 10), modified Standardized Assessment of Concussion (of 50), and balance examination (of 30).

RESULTS

The median number of symptoms reported at baseline ranged from 5 to 8 across sex and age stratifications. Median symptom severity was lowest in males with no concussion history (7; range, 0-28) and highest in females with a concussion history (13, range = 0-45). Median total scores on immediate memory were 2-3 (range = 0-4) for males and 21 (range = 9-29) for females. Median total scores were 3 (range = 0-4) on digits backward and 7 (range = 0-20) on delayed memory (all groups). Based on simultaneous quantile (q) regression at 0.50 and 0.75, adjusted for age and concussion history, being female was associated with a higher total symptoms score (q0.75 β_female = 2.85; 99% confidence interval [CI] = 0.33, 5.37), higher total symptom severity score (q0.75 β_female = 8.00; 99% CI = 2.83, 13.17), and lower number of errors on the balance examination (q0.75 β_female = -3.00; 99% CI = -4.85, -1.15). Age and concussion history were not associated with any summary measures.

CONCLUSIONS

The 10-word list option in the memory section reduced the likelihood of a ceiling effect. A player's sex may be an important consideration when interpreting the SCAT5 after concussion.

'Active & Safe Central': development of an online resource for the prevention of injury in sport and recreational activity

BACKGROUND

Sport and recreation related injuries exert a significant cost on the healthcare system. As prevention researchers and practitioners, we have a responsibility to provide guidance towards prevention to those who participate in sport and recreation, and those that coach, treat and parent children that participate. The objective of this project was to use an integrated knowledge translation approach to develop an end user-driven digital platform that provides injury prevention information and resources across 51 sport and recreational activities.

DESIGN

We used an integrated knowledge translation approach to scope and develop an online sport and recreational injury prevention resource. A project team was formed that included end users-coaches, parents and athletes, injury researchers and practitioners, as well as members of a digital design team. All members of the project team informed the development process, including a review of literature and existing resources, the translation of evidence and development of the platform. At all stages of development, members of the project team cocreated knowledge for the tool, including forming the research questions, the approach, feasibility and development of outcomes.

CONCLUSION

The 'Active & Safe Central' (https://activesafe.ca/) platform provides web-based sport injury and prevention information. This user-friendly, web and mobile accessible platform can increase the reach, awareness and implementation of prevention programming in sport and recreational activity.

What strategies can be used to effectively reduce the risk of concussion in sport? A systematic review

AIM OR OBJECTIVE

To examine the effectiveness of concussion prevention strategies in reducing concussion risk in sport.

DESIGN

Systematic review according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines.

DATA SOURCES

Eleven electronic databases searched and hand-search of references from selected studies.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

The following were the study inclusion criteria: (1) contained original human research data; (2) investigated an outcome of concussion or head impact; (3) evaluated a concussion prevention intervention; (4) included sport participants; (5) analytical study designand (6) peer-reviewed. The following were the exclusion criteria: (1) review articles, case series or case studies and (2) not in English.

RESULTS

The studies selected (n=48) provided evidence related to protective gear (helmets, headgear, mouthguards) (n=25), policy and rule changes (n=13) and other interventions (training, education, facilities) (n=10). Meta-analyses demonstrate a combined effect of a 70% reduction (incidence rate ratio (IRR)=0.3 (95% CI: 0.22 to 0.41)) in concussion risk in youth ice hockey leagues where policy disallows body checking, and the point estimate (IRR=0.8 (95% CI: 0.6 to 1.1)) suggests a protective effect of mouthguards in contact and collision sport (basketball, ice hockey, rugby).

SUMMARY/CONCLUSIONS

Highlights include a protective effect of helmets in skiing/snowboarding and the effectiveness of policy eliminating body checking in youth ice hockey. Future research should examine mouthguards in contact sport, football helmet padding, helmet fit in collision sport, policy limiting contact practice in youth football, rule enforcement to reduce head contact in ice hockey and soccer, ice surface size and board/glass flexibility in ice hockey and training strategies targeting intrinsic risk factors (eg, visual training).

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2016:CRD42016039162.

The Effect of the "Zero Tolerance for Head Contact" Rule Change on the Risk of Concussions in Youth Ice Hockey Players

BACKGROUND

Ice hockey is a popular winter sport in Canada. Concussions account for the greatest proportion of all injuries in youth ice hockey. In 2011, a policy change enforcing "zero tolerance for head contact" was implemented in all leagues in Canada.

PURPOSE

To determine if the risk of game-related concussions and more severe concussions (ie, resulting in >10 days of time loss) and the mechanisms of a concussion differed for Pee Wee class (ages 11-12 years) and Bantam class (ages 13-14 years) players after the 2011 "zero tolerance for head contact" policy change compared with players in similar divisions before the policy change.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The retrospective cohort included Pee Wee (most elite 70%, 2007-2008; n = 891) and Bantam (most elite 30%, 2008-2009; n = 378) players before the rule change and Pee Wee (2011-2012; n = 588) and Bantam (2011-2012; n = 242) players in the same levels of play after the policy change. Suspected concussions were identified by a team designate and referred to a sport medicine physician for diagnosis. Incidence rate ratios (IRRs) were estimated based on multiple Poisson regression analysis, controlling for clustering by team and other important covariates and offset by game-exposure hours. Incidence rates based on the mechanisms of a concussion were estimated based on univariate Poisson regression analysis.

RESULTS

The risk of game-related concussions increased after the head contact rule in Pee Wee (IRR, 1.85; 95% CI, 1.20-2.86) and Bantam (IRR, 2.48; 95% CI, 1.17-5.24) players. The risk of more severe concussions increased after the head contact rule in Pee Wee (IRR, 4.12; 95% CI, 2.00-8.50) and Bantam (IRR, 7.91; 95% CI, 3.13-19.94) players. The rates of concussions due to body checking and direct head contact increased after the rule change.

CONCLUSION

The "zero tolerance for head contact" policy change did not reduce the risk of game-related concussions in Pee Wee or Bantam class ice hockey players. Increased concussion awareness and education after the policy change may have contributed to the increased risk of concussions found after the policy change.

Broccoli sprout supplementation during pregnancy prevents brain injury in the newborn rat following placental insufficiency

Chronic placental insufficiency and subsequent intrauterine growth restriction (IUGR) increase the risk of hypoxic-ischemic encephalopathy in the newborn by 40 fold. The latter, in turn, increases the risk of cerebral palsy and developmental disabilities. This study seeks to determine the effectiveness of broccoli sprouts (BrSp), a rich source of the isothiocyanate sulforaphane, as a neuroprotectant in a rat model of chronic placental insufficiency and IUGR. Placental insufficiency and IUGR was induced by bilateral uterine artery ligation (BUAL) on day E20 of gestation. Dams were fed standard chow or chow supplemented with 200mg of dried BrSp from E15 - postnatal day 14 (PD14). Controls received Sham surgery and the same dietary regime. Pups underwent neurologic reflex testing and open field testing, following which they were euthanized and their brains frozen for neuropathologic assessment. Compared to Sham, IUGR pups were delayed in attaining early reflexes and performed worse in the open field, both of which were significantly improved by maternal supplementation of BrSp (p<0.05). Neuropathology revealed diminished white matter, ventricular dilation, astrogliosis and reduction in hippocampal neurons in IUGR animals compared to Sham, whereas broccoli sprout supplementation improved outcome in all histological assessments (p<0.05). Maternal dietary supplementation with BrSp prevented the detrimental neurocognitive and neuropathologic effects of chronic intrauterine ischemia. These findings suggest a novel approach for prevention of cerebral palsy and/or developmental disabilities associated with placental insufficiency.

Timing of translation in cross-language qualitative research

Although there is increased understanding of language barriers in cross-language studies, the point at which language transformation processes are applied in research is inconsistently reported, or treated as a minor issue. Differences in translation timeframes raise methodological issues related to the material to be translated, as well as for the process of data analysis and interpretation. In this article we address methodological issues related to the timing of translation from Portuguese to English in two international cross-language collaborative research studies involving researchers from Brazil, Canada, and the United States. One study entailed late-phase translation of a research report, whereas the other study involved early phase translation of interview data. The timing of translation in interaction with the object of translation should be considered, in addition to the language, cultural, subject matter, and methodological competencies of research team members.

Assessing thoracoabdominal asynchrony

The traditional method of derivation of phase difference between ribcage and abdomen breathing movements from a Lissajous plot is shown to be unsatisfactory for assessing the degree of asynchrony. The signal processing technique of cross-correlation is introduced as a better, statistically based approach. Even so, examination of the latent structure of a Lissajous figure leads to the concept of movement sum and difference components along its principal axes. This more general form of analysis is used for indicating relative changes in tidal volume during postoperative monitoring of Cheyne-Stokes breathing with obstructive apnoea, as well as tracking the degree of asynchrony. The theoretical and practical limitations of inductive plethysmography calibrations are such that the proposed methods of uncalibrated non-invasive respiratory monitoring are also preferable as research tools.

A systematic review of comparisons of effect sizes derived from randomised and non-randomised studies

BACKGROUND

There is controversy about the value of evidence about the effectiveness of healthcare interventions from non-randomised study designs. Advocates for quasi-experimental and observational (QEO) studies argue that evidence from randomised controlled trials (RCTs) is often difficult or impossible to obtain, or is inadequate to answer the question of interest. Advocates for RCTs point out that QEO studies are more susceptible to bias and refer to published comparisons that suggest QEO estimates tend to find a greater benefit than RCT estimates. However, comparisons from the literature are often cited selectively, may be unsystematic and may have failed to distinguish between different explanations for any discrepancies observed.

OBJECTIVES

The aim was to investigate the association between methodological quality and the magnitude of estimates of effectiveness by comparing systematically estimates of effectiveness derived from RCTs and QEO studies. Quantifying any such association should help healthcare decision-makers to judge the strength of evidence from non-randomised studies. Two strategies were used to minimise the influence of differences in external validity between RCTs and QEO studies: a comparison of the RCT and QEO study estimates of effectiveness of any intervention, where both estimates were reported in a single paper a comparison of the RCT and QEO study estimates of effectiveness for specified interventions, where the estimates were reported in different papers. The authors also sought to identify study designs that have been proposed to address one or more of the problems often found with conventional RCTs.

METHODS

DATA SOURCES

Relevant literature was identified from: The Cochrane Library, MEDLINE, EMBASE, DARE, and the Science Citation Index. References of relevant papers already identified experts. Electronic searches were very difficult to design and yielded few papers for the first strategy and when identifying study designs. CHOICE OF INTERVENTIONS TO REVIEW FOR STRATEGIES 1 AND 2: For strategy 1, any intervention was eligible. For strategy 2, interventions for which the population, intervention and outcome investigated were anticipated to be homogeneous across studies were selected for review: Mammographic screening (MSBC) of women to reduce mortality from breast cancer. Folic acid supplementation (FAS) to prevent neural tube defects in women trying to conceive. DATA EXTRACTION AND QUALITY ASSESSMENT: Data were extracted by the first author and checked by the second author. Disagreements were negotiated with reference to the paper concerned. For strategy 1, study quality was scored using a checklist to assess whether the RCT and QEO study estimates were derived from the same populations, whether the assessment of outcomes was 'blinded', and the extent to which the QEO study estimate took account of possible confounding. For strategy 2, a more detailed instrument was used to assess study quality on four dimensions: the quality of reporting, the generalisability of the results, and the extent to which estimates of effectiveness may have been subject to bias or confounding. All quality assessments were carried out by three people. DATA SYNTHESIS AND ANALYSIS: For strategy 1, pairs of comparisons between RCT and QEO study estimates were classified as high or low quality. Seven indices of the size of discrepancies between estimates of effect size and outcome frequency were calculated, where possible, for each comparison. Distributions of the size and direction of discrepancies were compared for high- and low-quality comparisons. FOR STRATEGY 2, THREE ANALYSES WERE CARRIED OUT: Attributes of the instrument were described by k statistics, percentage agreement, and Cronbach's a values. Regression analyses were used to investigate -variations in study quality. (ABSTRACT TRUNCATED)

Progress in non-invasive respiratory monitoring using uncalibrated breathing movement components

The theory for optimal linear combination of uncalibrated breathing movements was developed and applied in non-invasive respiratory monitoring situations for assessment. 16 patients were monitored overnight for respiratory depression during postoperative pain treatment. Intranasal/extra-oral airway pressure monitoring and pulse oximetry signals were recorded at 50 Hz. Respiratory inductive plethysmography (RIP) provided guidance to nurses regarding sensitivity settings of the pressure device during slow, shallow breathing, and vital information about breathing movements to help distinguish central from obstructive apnoeas. Subsequent analysis showed that the principal components of the standardized RIP signals would be helpful in any automated identification of pressure indicator false alarms and could provide a simple means for supplementary breath classification. The sum and difference of the scaled RIP values tracked changes in tidal volume and indicated any breathing movement asynchrony or paradox associated with obstructions. A construction was developed for emulating RIP calibration predictions of relative changes in tidal volume to within about 1%, so that invasive or demanding monitoring preparations could be by-passed altogether. The necessary signal combination and linearcalibration model background is reviewed for this simple formulation, which arises from component analysis and least squares regression. The methods are illustrated for definitive non-invasive postoperative monitoring and calibration situations. Theoretical and physiological reasons for preferring the use of balanced ribcage and abdomen contributions to overall tidal volume are presented that also help clarify the greater limitations of traditional RIP monitoring practices.

A systematic review of comparisons of effect sizes derived from randomised and non-randomised studies

BACKGROUND

There is controversy about the value of evidence about the effectiveness of healthcare interventions from non-randomised study designs. Advocates for quasi-experimental and observational (QEO) studies argue that evidence from randomised controlled trials (RCTs) is often difficult or impossible to obtain, or is inadequate to answer the question of interest. Advocates for RCTs point out that QEO studies are more susceptible to bias and refer to published comparisons that suggest QEO estimates tend to find a greater benefit than RCT estimates. However, comparisons from the literature are often cited selectively, may be unsystematic and may have failed to distinguish between different explanations for any discrepancies observed.

OBJECTIVES

The aim was to investigate the association between methodological quality and the magnitude of estimates of effectiveness by comparing systematically estimates of effectiveness derived from RCTs and QEO studies. Quantifying any such association should help healthcare decision-makers to judge the strength of evidence from non-randomised studies. Two strategies were used to minimise the influence of differences in external validity between RCTs and QEO studies: a comparison of the RCT and QEO study estimates of effectiveness of any intervention, where both estimates were reported in a single paper a comparison of the RCT and QEO study estimates of effectiveness for specified interventions, where the estimates were reported in different papers. The authors also sought to identify study designs that have been proposed to address one or more of the problems often found with conventional RCTs.

METHODS

DATA SOURCES

Relevant literature was identified from: The Cochrane Library, MEDLINE, EMBASE, DARE, and the Science Citation Index. References of relevant papers already identified experts. Electronic searches were very difficult to design and yielded few papers for the first strategy and when identifying study designs. CHOICE OF INTERVENTIONS TO REVIEW FOR STRATEGIES 1 AND 2: For strategy 1, any intervention was eligible. For strategy 2, interventions for which the population, intervention and outcome investigated were anticipated to be homogeneous across studies were selected for review: Mammographic screening (MSBC) of women to reduce mortality from breast cancer. Folic acid supplementation (FAS) to prevent neural tube defects in women trying to conceive. DATA EXTRACTION AND QUALITY ASSESSMENT: Data were extracted by the first author and checked by the second author. Disagreements were negotiated with reference to the paper concerned. For strategy 1, study quality was scored using a checklist to assess whether the RCT and QEO study estimates were derived from the same populations, whether the assessment of outcomes was 'blinded', and the extent to which the QEO study estimate took account of possible confounding. For strategy 2, a more detailed instrument was used to assess study quality on four dimensions: the quality of reporting, the generalisability of the results, and the extent to which estimates of effectiveness may have been subject to bias or confounding. All quality assessments were carried out by three people. DATA SYNTHESIS AND ANALYSIS: For strategy 1, pairs of comparisons between RCT and QEO study estimates were classified as high or low quality. Seven indices of the size of discrepancies between estimates of effect size and outcome frequency were calculated, where possible, for each comparison. Distributions of the size and direction of discrepancies were compared for high- and low-quality comparisons. FOR STRATEGY 2, THREE ANALYSES WERE CARRIED OUT: Attributes of the instrument were described by k statistics, percentage agreement, and Cronbach's a values. Regression analyses were used to investigate -variations in study quality. (ABSTRACT TRUNCATED)