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

Safe2Play in youth ice hockey: injury profile and risk factors in a 5-year Canadian longitudinal cohort study

INTRODUCTION

Ice hockey is a popular global sport with growing participation for boys and girls yet remains a high-risk sport for injury. While the evidence for some risk factors, such as bodychecking policy is well established, other risk factors such as player sex have been understudied. The objectives of this study were to examine factors associated with rates of game-related injury, game-related injury resulting in >7 days of time-loss, and practice-related injury in youth ice hockey.

MATERIALS AND METHODS

Safe2Play was a five-year prospective cohort study (2013-2018). All injuries were identified using validated injury surveillance methodology. Multilevel Poisson regression (adjusting for cluster by team and including multiple imputation of missing covariates) was used to estimate incidence rate ratios (IRRs) for player sex, age group, bodychecking policy, year of play, level of play, weight, previous injury within last 12 months, previous lifetime concussion history, and position.

RESULTS

A total of 4418 male and female ice hockey players (representing 6584 player-seasons) participating in under-13 (ages 11-12), under-15 (ages 13-14) and under-18 (ages 15-17) age groups were recruited. There were 1184 game-related and 182 practice-related injuries. Factors associated with game-related injury included female sex (IRR = 1.57; 95% CI: 1.18-2.08), previous injury (IRR = 1.46; 95% CI: 1.26-1.70) and lifetime concussion history (IRR = 1.41; 95% CI: 1.23-1.62). Goaltenders had a lower rate of injury (IRR = 0.54; 95% CI: 0.40-0.72) relative to forwards, as did players exposed to policy disallowing bodychecking in games (IRR = 0.44; 95% CI: 0.35-0.55). Female sex (IRR = 1.90; 95% CI: 1.10-3.28) and lifetime concussion history were also significantly associated with practice-related injury (IRR = 1.53; 95% CI: 1.08-2.18).

CONCLUSIONS

Based on data from a large 5-year Canadian youth ice hockey longitudinal cohort, several factors associated with injury were identified. Future injury prevention strategies should consider age, sex, previous concussion and injury history, and body checking leagues. Future research in female youth ice hockey including female-only leagues should be a priority to inform prevention strategies in this understudied population.

Concussion incidence and mechanisms differ between elite females and males in Australian Football

OBJECTIVES

To investigate the incidence and the game circumstances of concussion in the professional female (AFLW) and male (AFL) competitions of Australian Football, to identify potential targets for risk reduction.

DESIGN

Retrospective cohort.

METHODS

Concussion data were obtained from the AFL injury database, which included all concussions sustained by AFL (Male) players from 2015 to 18 and AFLW (Female) players from 2017 to 19. Concussions were diagnosed by experienced clinicians utilising standardised concussion assessment tools and injury definitions, as well as video review. Video footage was analysed to determine the circumstances each concussion occurred, which included the action and the contact-point of impact.

RESULTS

The incidence of concussion was higher in the AFLW (Female) compared to the AFL (Male) (IRR = 2.12, 95 %CI 1.54 to 2.92). Video footage was available for 194/252 (77 %) concussions in the AFL and 35/44 (80 %) concussions in the AFLW. Male players were most frequently concussed during marking contests (28 %) with primary impact from the upper limb (22 %) or the shoulder (19 %). Conversely, being bumped (23 %) or tackled (20 %) were the main actions associated with concussion in female players, with the head (29 %) or the ground (23 %) the most common contact-points of impact.

CONCLUSIONS

In elite Australian Football a higher incidence of concussion was demonstrated in female compared to male players. The mechanisms associated with concussion were also found to differ between male and female competitions, suggesting that different injury prevention interventions may be beneficial. In particular, a review of tackling and bumping skills training and education in the AFLW may reduce the risk of concussion.

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.

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.

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.

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.

Are Self-Reported and Parent-Reported Attention Problems and Hyperactivity Associated With Higher Rates of Concussion in Youth Ice Hockey Players?

OBJECTIVE

To examine the association between self-reported and parent-reported attention problems and hyperactivity and rates of injury and concussion in Canadian youth ice hockey players.

DESIGN

Secondary analyses of 2 prospective cohort studies.

SETTING

Canadian youth ice hockey teams.

PARTICIPANTS

Ice hockey players (ages 11-17 years) were recruited by team, over 4 seasons (2011-2016). A combined 1709 players contributing 1996 player-seasons were analyzed (257 players participated in more than one season).

ASSESSMENT OF RISK FACTORS

Data were collected from preseason baseline questionnaires, including child and parent proxy forms of the Behavior Assessment System for Children, second edition.

MAIN OUTCOME MEASURES

Injury and concussion rates and incidence rate ratios (IRR) comparing players with and without self-identified or parent-identified attention problems and hyperactivity, adjusted for covariates (ie, body checking policy, previous injury/concussion, and age) and a random effect for team, were estimated using multiple multilevel negative binomial regression.

RESULTS

When analyzed continuously, rates of concussion increased with higher self-reported and parent-reported measures of attention problems [IRR SELF = 1.025; 95% confidence interval (CI): 1.011-1.040; IRR PARENT = 1.032; 95% CI: 1.008-1.057]. Self-reported hyperactivity was significantly associated with concussion (IRR = 1.021; 95% CI: 1.007-1.035), but parent-reported hyperactivity was not (IRR = 1.005; 95% CI: 0.983-1.028). A T score ≥ 60 cutoff combining attention problems and hyperactivity scores (an estimate of probable attention-deficit hyperactivity disorder) was not significantly associated with rates of injury or concussion.

CONCLUSIONS

Attention problems and hyperactivity may place youth ice hockey players at increased risk of concussion and injury. Preseason assessments could identify players for targeted concussion education and risk reduction strategies.

No association found between body checking experience and injury or concussion rates in adolescent ice hockey players

OBJECTIVES

To compare rates of injury and concussion among U-15 (ages 13-14 years) ice hockey players playing in leagues allowing body checking, but who have a varying number of years of body checking experience.

METHODS

This 5-year longitudinal cohort included U-15 ice hockey players playing in leagues where policy allowed body checking. Years of body checking experience were classified based on national/local body checking policy. All ice hockey game-related injuries were identified using a validated injury surveillance methodology. Players with a suspected concussion were referred to a study sport medicine physician. Multiple multilevel Poisson regression analysis was performed, adjusting for important covariates and a random effect at a team level (offset by game exposure hours), to estimate injury and concussion incidence rate ratios (IRRs).

RESULTS

In total, 1647 players participated, contributing 1842 player-seasons (195 players participating in two seasons). Relative to no body checking experience, no significant differences were found in the adjusted IRRs for game-related injury for players with 1 year (IRR=1.06; 95% CI: 0.77 to 1.45) or 2+ years (IRR=1.16; 95% CI: 0.74 to 1.84) body checking experience. Similarly, no differences were found in the rates of concussion for players with 1 year (IRR=0.92; 95% CI: 0.59 to 1.42) or 2+ years (IRR=0.69; 95% CI: 0.38 to 1.25) body checking experience.

CONCLUSIONS

Among ice hockey players aged 13-14 years participating in leagues permitting body checking, the adjusted rates of all injury and concussion were not significantly different between those that had body checking experience and those that did not. Based on these findings, no association was found between body checking experience and rates of injury or concussion specifically in adolescent ice hockey.

Injuries in Youth Volleyball Players at a National Championship: Incidence, Risk Factors, and Mechanisms of Injury

OBJECTIVE

To evaluate injury incidence rates, types, mechanisms, and potential risk factors in youth volleyball.

DESIGN

Prospective cohort.

SETTING

2018 Canadian Youth National Volleyball Tournament.

PARTICIPANTS

Thousand eight hundred seventy-six players [466 males, 1391 females, mean age 16.2 years (±1.26)] consented to participate (19.5%).

ASSESSMENT OF RISK FACTORS

Sex (male/female), age group, position, and underage players.

MAIN OUTCOME MEASURES

Players completed a questionnaire (demographic information, injury, and concussion history). Medical attention injuries were recorded by tournament medical personnel through an injury report form (eg, mechanism and type). Injury was defined as any physical complaint seeking onsite medical attention. Concussion was defined using the fifth International Consensus. Injury rates adjusted for cluster by team were calculated by sex. Exploratory multivariable Poisson regression was used to analyze potential risk factors (eg, sex, age group, position, and underage players) for injury, adjusted for cluster by team and offset by athlete exposures (AEs).

RESULTS

There were 101 injuries in the 7-day tournament {IRFemale = 6.78 injuries/1000 AEs [95% confidence interval (CI), 5.27-8.72]; IRMale = 4.30 injuries/1000 AEs (95% CI, 2.55-7.24)}. Joint sprain (n = 29, 28.71%) and concussion (n = 26, 25.74%) were the most common. Most concussions were associated with ball-to-head contact (61.5%). There was no statistically significant difference in injury rate by sex (IRRF/M: 1.47; 95% CI, 0.80-2.69). The rates of injury in U14 were higher than U18 (IRRU14: 2.57; 95% CI, 1.11-5.98).

CONCLUSIONS

Injury rates are high in youth volleyball tournament play, with the highest rates in U14. More research is needed to inform the development of volleyball-specific injury prevention strategies.

Does Increasing the Severity of Penalties Assessed in Association With the "Zero Tolerance for Head Contact" Policy Translate to a Reduction in Head Impact Rates in Youth Ice Hockey?

OBJECTIVE

The risk of concussion is high in Canadian youth ice hockey. Aiming to reduce this burden, in 2011, Hockey Canada implemented a national "zero tolerance for head contact (HC)" policy mandating the penalization of any player HC. In 2018 to 2020, Hockey Canada further amended this HC policy including stricter enforcement of severe HCs. This study aimed to compare HC rates, head impact location, and HC enforcement prepolicy, postpolicy, and after policy amendments in elite U15 Canadian youth ice hockey.

DESIGN

This is a prospective cohort study.

SETTING

A collection of events with the video camera located at the highest point near center ice in public ice hockey arenas in Calgary, Alberta.

PARTICIPANTS

A convenience sample of 10 AA U15 games prepolicy (2008-2009), 8 games postpolicy (2013-2014), and 10 games after policy amendments (2020-2021).

INDEPENDENT VARIABLES

An analysis of 3 cohort years regarding the HC-policy implementation and amendments.

MAIN OUTCOME MEASURES

Using Dartfish video-analysis software, all player contacts and HCs [direct (HC1), indirect (eg, boards, ice) (HC2)] were tagged using validated criteria. Univariate Poisson regression clustering by team-game offset by game length (minutes) was used to estimate incidence rates (IR) and incidence rate ratios (IRR) between cohorts.

RESULTS

With additional rule modifications, a 30% reduction in HC1s emerged (IRR 2013-2020 = 0.70, 95% CI, 0.51-0.95). Since the HC-policy implementation, HC1s decreased by 24% (IRR 2008-2020 = 0.76, 95% CI, 0.58-0.99). The proportion of HC1s penalized was similar across cohorts (P 2008-2009 = 14.4%; P 2013-2014 = 15.5%; P 2020-2021 = 16.2%).

CONCLUSIONS

The HC-policy amendments have led to decreased HC1 rates. However, referee enforcement can further boost the HC-policy effectiveness. These findings can help future referee training and potential rule modifications to increase player safety nationally.

Epidemiology of female youth ice hockey injuries presenting to United States emergency departments from 2002 to 2019

BACKGROUND

This study documented injury types, rates and mechanisms for female youth ice hockey players reporting to US emergency departments to inform safety measures and sideline medical preparedness.

METHODS

The National Electronic Injury Surveillance System (NEISS) database was queried for ice hockey injuries (product code 1279) from 1 January 2002 to 31 December 2019. Incidence rate ratios (IRR) were calculated using OpenEpi and compared between age divisions. Spearman's rank correlation was utilized to evaluate the correlation between age and injury incidence. USA Hockey membership statistics were used to establish the population at risk and calculate incidence rates (IR).

RESULTS

An estimated 20,384 ice hockey injuries presented to participating United States emergency departments. The number of female youth ice hockey players increased significantly from 36,258 in 2002 to 65,072 in 2019 (p < 0.01). The most commonly injured body parts were the head (n = 5,519, IR = 62.1 [95%CI 54.3-70.0 per 10,000 athletes), trunk (n = 2,364, IR = 26.6 [95%CI 21.2-32.0] per 10,000 athletes), and wrist (n = 1,824, IR = 20.5 [95%CI 15.7-25.4] per 10,000 athletes). The most commonly reported mechanisms of injury were player-to-player collision (n = 4,746, IR = 53.4 [95%CI 46.4-60.5] per 10,000 athletes) and falls (n = 4,585, IR = 51.6 [95%CI 44.1-59.1] per 10,000 athletes). The most common diagnoses were traumatic brain injury (n = 5,333, IR = 60.0 [95%CI 52.3-67.8] per 10,000 athletes), contusion (n = 4,204, IR = 47.3 [95%CI 40.3-54.4] per 10,000 athletes) and strain/sprain (n = 3,601, IR = 40.5 [95%CI 34.1-47.0] per 10,000 athletes). A positive correlation was found between age and injury incidence, as well as increasing age and injuries from player-to-player collision and TBI's.

CONCLUSIONS

Though body checking is illegal at all levels of women's ice hockey, player-to-player collision prevailed as the leading mechanism on injury. Hopefully this study informs players, parents, coaches, trainers and clinicians about the impact of player-to-player collisions on overall injury burden in the older age divisions of youth female hockey.

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.

Basketball vs. Hockey-The Changing Face of Sport-Related Injuries in Canada

OBJECTIVE

To characterize and compare the incidence of basketball-related, soccer-related, and hockey-related injuries over a 10-year period.

DESIGN

Cohort analysis of sport-related injuries using multiple Ontario healthcare databases.

SETTING

Emergency department visits in Ontario, Canada.

PATIENTS

Any patient who sustained musculoskeletal injuries sustained while playing basketball, soccer, or hockey between 2006 and 2017 were identified.

ASSESSMENT OF RISK FACTORS

Sport of injury, age, sex, rurality index, marginalization status, and comorbidity score.

MAIN OUTCOME MEASURES

Annual Incidence Density Rates of injury were calculated for each sport, and significance of trends was analyzed by assessing overlap of 95% confidence intervals.

RESULTS

One lakhs eighty five thousand eighty hundred sixty-eight patients (median age: 16 years, interquartile range 13-26) received treatment for sport-related injuries (basketball = 55 468; soccer = 67 021; and hockey = 63 379). The incidence of basketball-related and soccer-related injuries increased from 3.4 (3.3-3.5) to 5.6 (5.5-5.7) and 4.4 (4.3-4.5) to 4.9 (4.8-5) per 10 000 person years, respectively, whereas the incidence of hockey-related injuries decreased from 4.7 (4.6-4.8) to 3.7 (3.6-3.8). Patients with basketball injuries were more marginalized (3.01 ± 0.74) compared with patients with soccer and hockey injuries (2.90 ± 0.75 and 2.72 ± 0.69, respectively).

CONCLUSIONS

Accurate regional epidemiologic information regarding sports injuries can be used to guide policy development for municipal planning and sport program development. The trends and demographic patterns described highlight general and sport-specific injury patterns in Ontario. Populations with the highest incidence of injury, most notably adolescents and men older than 50, may represent an appropriate population for injury risk prevention.

Male Youth Ice Hockey Concussion Incidence in a USA Hockey Membership-Adjusted Population: A Peak in 2011 and the Impact of Major Rule Changes

OBJECTIVE

To investigate the incidence of youth ice hockey-related concussions preceding and following the implementation of new body-checking and head contact rules by USA hockey in 2011. We hypothesized a decrease in concussions after the rule change.

DESIGN

Retrospective analysis.

SETTING

United States emergency department (ED) data queried in the National Electronic InjurySurveillance System (NEISS).

PATIENTS

National Electronic Injury Surveillance System reported male youth (≤18 years) ice hockey concussion cases from January 1, 2002, to December 31, 2016. In total, 848 players were diagnosed with concussion, representing a national estimate of 17 374 cases.

INDEPENDENT VARIABLES

Time, specifically years.

MAIN OUTCOME MEASURES

Incidences and incidence rates (measured per 10 000 person-years) of male youth ice hockey concussions. Annual trends were analyzed using descriptive and linear or polynomial regression analysis.

RESULTS

The national estimate of youth ice hockey-related concussions seen in US emergency departments (EDs) increased significantly from 656 in 2007 to 2042 in 2011 (P < 0.01). During the same period, their respective incidence increased significantly from 21.8 to 66.8 per 10 000, before dropping through 2016 (P < 0.05). After 2011, concussions decreased from 1965 in 2012 to 1292 in 2016 (P = 0.055). The gap in concussion incidence between the 11 to 12 and 13 to 14 divisions widened after 2011 (before 2011: 41 vs 49 per 10 000 person-years [P = 0.80]; after 2011: 45 and 89, respectively [P < 0.01]).

CONCLUSIONS

US EDs experienced a significant increase in youth ice hockey concussion visits from 2007 to 2011. After the 2011 rule changes, concussion visits decreased significantly from 2012 to 2016.

Body checking in non-elite adolescent ice hockey leagues: it is never too late for policy change aiming to protect the health of adolescents

OBJECTIVES

The objective of this study is to evaluate the effect of policy change disallowing body checking in adolescent ice hockey leagues (ages 15-17) on reducing rates of injury and concussion.

METHODS

This is a prospective cohort study. Players 15-17 years-old were recruited from teams in non-elite divisions of play (lower 40%-70% by division of play depending on year and city of play in leagues where policy permits or prohibit body checking in Alberta and British Columbia, Canada (2015-18). A validated injury surveillance methodology supported baseline, exposure-hours and injury data collection. Any player with a suspected concussion was referred to a study physician. Primary outcomes include game-related injuries, game-related injuries (>7 days time loss), game-related concussions and game-related concussions (>10 days time loss).

RESULTS

44 teams (453 player-seasons) from non-body checking and 52 teams (674 player-seasons) from body checking leagues participated. In body checking leagues there were 213 injuries (69 concussions) and in non-body checking leagues 40 injuries (18 concussions) during games. Based on multiple multilevel mixed-effects Poisson regression analyses, policy prohibiting body checking was associated with a lower rate of injury (incidence rate ratio (IRR): 0.38 (95% CI 0.24 to 0.6)) and concussion (IRR: 0.49; 95% CI 0.26 to 0.89). This translates to an absolute rate reduction of 7.82 injuries/1000 game-hours (95% CI 2.74 to 12.9) and the prevention of 7326 injuries (95% CI 2570 to 12083) in Canada annually.

CONCLUSIONS

The rate of injury was 62% lower (concussion 51% lower) in leagues not permitting body checking in non-elite 15-17 years old leagues highlighting the potential public health impact of policy prohibiting body checking in older adolescent ice hockey players.

Reduction of High School Ice Hockey Injuries With Implementation of New Checking/Boarding Rules

OBJECTIVE

Evaluate whether rule changes by the National Federation of State High School Associations (NFHS) were associated with reduced injury rates in US high school ice hockey players.

DESIGN

We compared injury rates for the 3 seasons before the rule changes (2011-2012, 2012-2013, and 2013-2014) with the 2 subsequent seasons (2014-2015 and 2015-2016) using data from the High School Reporting Information Online (RIO) database.

SETTING

Convenience sample of US high schools.

PARTICIPANTS

High school ice hockey athletes.

INTERVENTIONS

The sports injury surveillance system that supplied the data for this study was funded in part by the Centers for Disease Control and Prevention (grant Nos. R49/CE000674-01, R49/CE001172-01, and R49/CE002106-01) as well as research funding contributions of the NFHS, National Operating Committee on Standards for Athletic Equipment (NOCSAE), DonJoy Orthotics, and EyeBlack. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention or any other funding agency. In the 2014 to 2015 ice hockey season, the NFHS increased the penalty for boarding (illegally causing opponent to be thrown violently into the boards) and for checking from behind.

MAIN OUTCOME MEASURES

Injury rates and mechanism of injury.

RESULTS

There was a statistically significant 40% reduction in rates of injury attributed to being checked in the 2 seasons after the rule changes (5.0 injuries per 10 000 athlete exposures) compared with the 3 previous seasons (8.3) (rate ratio = 0.60, P = 0.002). There were no significant differences in overall injury rates (P = 0.12) or injury rates due to checking (P = 0.27), contact with the boards (P = 0.31), or contact with another player (P = 0.55).

CONCLUSIONS

Among US high school ice hockey athletes, implementation of stricter penalties for boarding and checking from behind was associated with a significant decrease in injury rate due to being checked. Rates of injury due to other mechanisms were not significantly altered, suggesting the rule changes achieved their targeted effect.

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.

Helmet Fit Assessment and Concussion Risk in Youth Ice Hockey Players: A Nested Case-Control Study

CONTEXT

Injury surveillance has shown that concussions are the most common injury in youth ice hockey. Research examining the criteria for ensuring the correct fit of protective equipment and its potential relationship with concussion risk is very limited.

OBJECTIVE

To evaluate the association between helmet fit and the odds of experiencing a concussion among youth ice hockey players.

DESIGN

Nested case-control within a cohort study.

SETTING

Calgary, Alberta, Canada.

PATIENTS OR OTHER PARTICIPANTS

Data were collected for 72 concussed, 41 nonconcussion-injured, and 62 uninjured ice hockey players aged 11 to 18 years.

MAIN OUTCOME MEASURE(S)

Helmet-fit assessments were conducted across players and encompassed helmet specifications, condition, certification, and criteria measuring helmet fit. Using a validated injury-surveillance system, we identified participants as players with suspected concussions or physician-diagnosed concussions or both. One control group comprised players who sustained nonconcussion injuries, and a second control group comprised uninjured players. Helmet-fit criteria (maximum score = 16) were assessed for the concussed players and compared with each of the 2 control groups. The primary outcome was dichotomous (>1 helmet-fit criteria missing versus 0 or 1 criterion missing). Logistic and conditional logistic regression were used to investigate the effect of helmet fit on the odds of concussion.

RESULTS

The primary analysis (54 pairs matched for age, sex, and level of play) suggested that inadequate helmet fit (>1 criterion missing) resulted in greater odds of sustaining a concussion when comparing concussed and uninjured players (odds ratio [OR] = 2.67 [95% CI = 1.04, 6.81], P = .040). However, a secondary unmatched analysis involving all participants indicated no significant association between helmet fit and the odds of sustaining a concussion when we compared concussed players with nonconcussion-injured players (OR = 0.98 [0.43, 2.24], P = .961) or uninjured players (OR = 1.66 [0.90, 3.05], P = .103).

CONCLUSIONS

Inadequate helmet fit may affect the odds of sustaining a concussion in youth ice hockey players. Future investigators should continue to evaluate this relationship in larger samples to inform helmet-fit recommendations.

Rule Modifications to Reduce Checking-Related Injuries in High School Boys' Lacrosse

CONTEXT

The National Federation of State High School Associations previously implemented 2 lacrosse rule modifications: Rule 5.4 in the 2012-2013 academic year to heighten the penalty for a head or neck hit to the head, face, or neck (HFN) and Rule 5.3.5 in the 2013-2014 academic year to minimize body checking.

OBJECTIVE

To determine if the rates of overall injury, HFN injuries, and concussions due to intentional contact (checking) differed for boys' high school lacrosse players after Rule 5.4 and 5.3.5 modifications were enacted.

DESIGN

Descriptive epidemiology study.

SETTING

Web-based online surveillance system.

PATIENTS OR OTHER PARTICIPANTS

Boys' high school lacrosse players during the 2008-2009 to 2016-2017 seasons whose teams involved athletic trainers participating in the High School Reporting Information Online sports injury-surveillance system.

INTERVENTION(S)

Rule 5.4 in the 2012-2013 academic year increased the penalty for any intentional hits to the HFN, and Rule 5.3.5 in the 2013-2014 year eliminated body checking to a player in a defenseless position.

MAIN OUTCOME MEASURE(S)

Overall, HFN, and concussion injury rate ratios (IRRs) by checking mechanism; overall and checking-related injury ratios by competitions and practices.

RESULTS

A decrease was shown in checking-related HFN injuries (IRR = 0.29, 95% CI = 0.13, 0.65) and checking-related concussions (IRR = 0.29, 95% CI = 0.12, 0.70) during practices in the seasons after both rule modifications were imposed, but no decreases occurred in any checking-related injuries during competitions. By injury mechanism, no decreases were evident after the Rule 5.4 modification. When both rule modifications (Rules 5.4 and 5.3.5) were enacted together, concussion rates due to delivering body checks (IRR = 0.51, 95% CI = 0.29, 0.91) and overall injury risk due to being body checked (IRR = 0.72, 95% CI = 0.53, 0.97) decreased.

CONCLUSIONS

When both Rule 5.4 and 5.3.5 modifications were in effect, concussion and overall injury risks decreased for the body checker and the player being body checked, respectively.

Physical Conditioning Strategies for the Prevention of Concussion in Sport: a Scoping Review

BACKGROUND

Concussion in sports has received a great deal of media attention and may result in short and longer-lasting symptoms, especially in adolescents. Although significant strides have been made in the identification and management of concussion, less is known about the primary prevention of this condition. The aims of this scoping review are to (1) summarize the current research of physical conditioning strategies to reduce or prevent concussion incidence in individuals participating in sport, especially adolescents, and (2) to identify gaps in the knowledge base. Our research question was what is known from the existing literature about physical preparation strategies to reduce or prevent concussion in adult and adolescent sports?

METHODS

Three literature searches were conducted by information officers at two universities at six-month intervals, using five electronic databases (PubMed; WorldCat.org ; Mendeley; EBSCOHost and Ovid MEDLINE). To increase the search range, subject experts were consulted and articles and reference lists were hand searched. A scoping review methodology identified eligible studies that analyzed physical preparation techniques on modifiable physical risk factors in athletes to reduce the incidence of concussion. The PRISMA-ScR checklist guided the reporting of the findings.

RESULTS

A total of 1414 possible articles were identified, after duplicates removed, and articles analyzed against the inclusion and exclusion criteria, only 9 articles qualified for analysis. Two articles were found from studying reference lists. Thus, a total of 11 articles were included in the final evaluation for the purposes of this study. Data are reported from mostly adolescent subjects participating in nine different sports from three countries. Findings are presented with specific reference to previously recognized modifiable risk factors of concussion which include neck strength, neck size, cervical stiffness, type of sport, and pre-activity exercises.

CONCLUSIONS

There is limited research examining the physical preparation of athletes, especially in adolescents, to reduce or prevent concussion, and conflicting evidence in the few small sample studies that were identified. This scoping review identifies the research gap for a potentially vital modifiable risk factor, notably in the physical preparation of children and adolescents to reduce or prevent sports-related concussion.

Data-Driven Risk Classification of Concussion Rates: A Systematic Review and Meta-Analysis

BACKGROUND

Concussion is a growing public health concern and generating concussion prevention programs depends on identifying high-risk sports and characteristics. Identifying the roles of sport, sex, and participation level (e.g., high school versus collegiate athletics) in concussion risk would facilitate more informed decision-making regarding sports participation and generate better targeted prevention strategies.

OBJECTIVES

The current study's objectives were to: (1) determine the magnitude and hierarchy of sports-related concussion (SRC) risk across an array of events and (2) evaluate the modifying roles of sex, participation level, and session type on SRC rates.

METHODS

A literature search was conducted on PubMed, searching concussion studies published between 2001 and December 2019. Inclusion criteria for studies required: (1) concussion occurred during sport, (2) that the SRC was clinically diagnosed, and (3) athlete exposures and concussions could be extracted or estimated. A study was excluded if it: (1) was not an original research article, (2) was not written in English language, (3) was an animal study, (4) did not have enough data to calculate SRC rates, (5) included professional or youth sample, and/or (6) contained data collected prior to 2001. The meta-analysis and meta-regression analyses were fit using a random effects model.

RESULTS

Search results returned 2695 unique research articles, with 83 studies included in analyses. Sport, sex, participation level, and session type all significantly influenced SRC rates. Overall, rugby had the highest concussion rate and was classified as the highest risk sport (28.25 concussions per 10,000 athlete exposures). Overall, females had a higher concussion rate than males. Only lacrosse demonstrated a higher concussion rate for males compared to females. Collegiate athletes had higher concussion rates than high school athletes. Games were associated with 2.01 more concussions per 10,000 AEs than practices.

CONCLUSIONS

This meta-analysis demonstrated rugby has the highest concussion risk, followed by American Football, ice hockey, and wrestling. Concussion risk was influenced by sport, sex, participation, and session. Identifying the factors and environments that influence concussion risk can facilitate risk reduction and prevention strategies.

Incidence of Head Contacts, Penalties, and Player Contact Behaviors in Youth Ice Hockey: Evaluating the “Zero Tolerance for Head Contact” Policy Change

Background:

To reduce the risk of concussion in youth ice hockey, Hockey Canada implemented a national “zero tolerance for head contact” (HC) policy in 2011. A previous cohort study revealed higher concussion rates after this implementation in players aged 11 to 14 years. However, it is unknown whether the elevated risk was due to higher HC rates or factors such as increased concussion awareness and reporting.

Purpose:

To compare the rates of primary and secondary HCs and HC policy enforcement in elite U15 ice hockey leagues (players <15 years) before (2008-2009) and after (2013-2014) the zero-tolerance policy change.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 32 elite U15 games before (n_2008-2009 = 16; 510 players) and after (n_2013-2014 = 16; 486 players) HC policy implementation were video recorded. Videos were analyzed with validated criteria for identifying HC types (primary/direct contact by players [HC1], secondary/indirect contact via boards, glass, or ice surface [HC2]) and other player-to-player contact behavior. Referee-assessed penalties were cross-referenced with the official Hockey Canada casebook, and penalty types were displayed using proportions. Univariate Poisson regression (adjusted for cluster by team game, offset by game length [minutes]) was used to estimate HC incidence rates (IRs) and incidence rate ratios (IRRs) between cohorts.

Results:

A total of 506 HCs were analyzed, 261 before HC policy implementation (IR, 16.6/100 team minutes) and 245 after implementation (IR, 15.5/100 team minutes). The HC1 rate (IRR, 1.05; 95% CI, 0.86-1.28) and HC2 rate (IRR, 0.74; 95% CI, 0.50-1.11) did not significantly differ before versus after implementation. Only 12.0% and 13.6% of HC1s were penalized pre- and postimplementation, respectively. Before implementation, HC1s were commonly penalized as roughing or elbowing penalties (59%), while after implementation, HC1s were penalized with the HC penalty (76%), and only 8% as roughing or elbowing.

Conclusion:

Despite implementation of the “zero tolerance for HC” policy, there was no difference in the rate of HC1s and HC2s or the proportion of HC1 penalized from before to after implementation. This research is instrumental in informing Hockey Canada’s future referee training and rule enforcement modifications.

Heads Up Football Training Decreases Concussion Rates in High School Football Players

OBJECTIVE

The objective of this study was to determine whether football players receiving heads up (HU) training would display a lower rate of sport-related concussion (SRC) compared to those without HU training.

DESIGN

Prospective cohort.

SETTING

Scholastic football fields.

PATIENTS

Two thousand five hundred fourteen scholastic football players during the 2015 to 2016 football season were monitored throughout the football season.

INTERVENTIONS

Before the preseason, 1 coach from 14 schools received HU training from US football. These schools were matched with 10 control schools performing standard football training [non-heads up (NHU)]. Random monitoring for proper coaching instruction was performed during the season. School athletic trainers monitored injuries and return to sport over the season for all schools.

MAIN OUTCOME MEASURES

The outcome measures of concussions and associated time loss were determined before data collection began. Injury incidence and rate ratios were calculated to determine program effectiveness.

RESULTS

During the season, football players sustained 117 concussions (HU = 75; NHU = 42). The HU players displayed a significantly lower concussion rate (4.1 vs 6.0/100 players) compared with NHU teams [rate ratio = 1.5; 95% confidence interval (CI), 1.1-5.4]. The HU group returned to full participation 27% faster than athletes in the NHU group [time loss: 18.2 days (95% CI, 15.8-20.6) vs 24.8 days (95% CI, 19.9-29.7)], respectively.

CONCLUSIONS

This is the first study to evaluate the impact of the HU program on the incidence of SRC in high school football players. Our data demonstrated that the HU program reduced SRC rates by 33% supporting the use of US HU football training as an effective method to decrease the rate of SRCs in scholastic football.

CLINICAL RELEVANCE

This study is the first to prospectively explore the effect of HU training on the incidence and recovery from SRC in high school football players.

Head Impact Exposures Among Youth Tackle and Flag American Football Athletes

Background:

Promoted as a safer alternative to tackle football, there has been an increase in flag football participation in recent years. However, examinations of head impact exposure in flag football as compared with tackle football are currently limited.

Hypothesis:

Tackle football athletes will have a greater number and magnitude of head impacts compared with flag football athletes.

Study Design:

Cohort study.

Level of Evidence:

Level 4.

Methods:

Using mouthguard sensors, this observational, prospective cohort study captured data on the number and magnitude of head impacts among 524 male tackle and flag football athletes (6-14 years old) over the course of a single football season. Estimates of interest based on regression models used Bayesian methods to estimate differences between tackle and flag athletes.

Results:

There were 186,239 head impacts recorded during the study. Tackle football athletes sustained 14.67 (95% CI 9.75-21.95) times more head impacts during an athletic exposure (game or practice) compared with flag football athletes. Magnitude of impact for the 50th and 95th percentile was 18.15g (17.95-18.34) and 52.55g (51.06-54.09) for a tackle football athlete and 16.84g (15.57-18.21) and 33.51g (28.23-39.08) for a flag football athlete, respectively. A tackle football athlete sustained 23.00 (13.59-39.55) times more high-magnitude impacts (≥40g) per athletic exposure compared with a flag football athlete.

Conclusion:

This study demonstrates that youth athletes who play tackle football are more likely to experience a greater number of head impacts and are at a markedly increased risk for high-magnitude impacts compared with flag football athletes.

Clinical Relevance:

These results suggest that flag football has fewer head impact exposures, which potentially minimizes concussion risk, making it a safer alternative for 6- to 14-year-old youth football athletes.

Epidemiology of Concussions in High School Boys' Ice Hockey, 2008/09 to 2016/17 School Years

OBJECTIVE

This study examined the epidemiology of concussions in high school boys' ice hockey during the 2008/09 to 2016/17 school years.

DESIGN

Prospective cohort study. Athletic trainers from an average 33 high schools annually reported boys' ice hockey concussion and athlete-exposure (AE) data for the High School Reporting Information Online system.

SETTING

Convenience sample of high school boys' ice hockey programs during the 2008/09 to 2016/17 school years.

PATIENTS OR OTHER PARTICIPANTS

High school boys' ice hockey players (aged ∼14-18 years).

INDEPENDENT VARIABLES

Concussion data on event type, injury mechanism, symptom resolution time, and time loss were obtained.

MAIN OUTCOME MEASURES

Concussion rates with 95% confidence intervals (CIs) and distributions were calculated.

RESULTS

Overall, 348 concussions were reported in boys' ice hockey during the 2008/09 to 2016/17 academic years, leading to a concussion rate of 0.68/1000 AEs (95% CI, 0.61-0.75). Most occurred in competitions (85.6%), particularly after the first period (72.1% of all competition concussions). Among practice concussions, most occurred after the first hour of practice (60.0%). Most concussions were due to player contact (47.7%) and boards/glass contact (31.9%). Although 69.0% of concussed athletes had symptoms resolve in less than 7 days, only 14.1% returned to activity within a week.

CONCLUSIONS

Most concussions occurred within the second and third periods. Preventive strategies that counter an increased risk of concussion due to a greater intensity of gameplay coupled with increased fatigue may be warranted. Moreover, athletes may further benefit from prevention efforts that focus on anticipating impacts during gameplay.

Exposure to brain trauma in six age divisions of minor ice hockey

Acute and chronic neurological risks associated with brain trauma sustained in professional ice hockey has generated concern for youth participants. Minor hockey is a different game when compared to elite players presenting distinctive risk factors for each age division. Objective measures of brain trauma exposure were documented for six divisions in minor ice hockey; U7, U9, U11, U13, U15, U18. Game video analysis, physical reconstruction and computational modelling was employed to capture the event conditions, frequency of impacts, frequency of high strain magnitude (>0.17) impacts, and cumulative trauma. The results showed proportional differences in the event conditions; event type, closing velocity, and head impact location, informing the improvement of age appropriate protection, testing protocols, and safety standards. Frequency of events were highest for U7 when players were learning to skate, and again in U18 as game physicality increases. No significant difference was observed in frequency of high magnitude impacts across age divisions. A peak in high magnitude impacts was empirically observed at both U7 and U15 where skill development in skating and body checking, respectively, were most prominent. Finally, a cumulative trauma metric incorporating frequency and magnitude of impacts provided a detailed analysis of trauma exposure provides for a targeted approach to managing injury risk specific to age division. Objective measures of brain trauma exposure identified in the current study are important to inform strategy, guide legislation and initiate policy for safe play in minor ice hockey.

Nationwide sports injury prevention strategies: A scoping review

National strategies to prevent sports injuries can potentially improve health outcomes at a population level and reduce medical costs. To date, a compilation of the strategies that countries have attempted, and their effectiveness, does not exist. This scoping review sets out to: identify nationwide attempts at implementing sports injury prevention strategies; examine the impact of these strategies; and map them onto the Translating Research into Injury Prevention Practice (TRIPP) framework. Using Levac's scoping review method, we: (a) identified the research questions, (b) identified relevant studies, (c) identified the study selection criteria, (d) charted the data, and (e) reported the results. A search of MEDLINE, Scopus, SPORTDiscus, CINAHL, and Web of Science databases for articles published pre-June 2019 was conducted. We identified 1794 studies and included 33 studies (of 24 strategies). The USA (n = 7), New Zealand (n = 4), Canada (n = 3), the Netherlands (n = 3), Switzerland (n = 2), Belgium (n = 1), France (n = 1), Ireland (n = 1), South Africa (n = 1), and Sweden (n = 1) have implemented nationwide sports injury prevention strategies with 29 (88%) of the included studies demonstrating positive results. Mapping the strategies onto the TRIPP framework highlighted that only four (17%) of the 24 included strategies reported on the implementation context (TRIPP Stage 5), suggesting an important reporting gap. Nationwide sports injury prevention efforts are complex, requiring a multidimensional approach. Future research should report intervention implementation data; examine the implementation context early in the research process to increase the likelihood of real-world implementation success; and could benefit from incorporating qualitative or mixed research methods.

Concussion Symptom Characteristics and Resolution in 20 United States High School Sports, 2013/14-2017/18 Academic Years

BACKGROUND

High school (HS) sport-related concussions (SRCs) remain a public health concern in the United States.

OBJECTIVE

To describe patterns in symptom prevalence, symptom resolution time (SRT), and return-to-play time (RTP) for SRCs sustained in 20 HS sports during the 2013/14-2017/18 academic years.

METHODS

A convenience sample of athletic trainers reported concussion information to the HS RIOTM surveillance system. Symptom prevalence, average number of symptoms, and SRT and RTP distributions were examined and compared by event type (practice, competition), injury mechanism (person contact, nonperson contact), sex, and contact level (collision, high contact, and low contact) with chi-square tests and Wilcoxon rank-sum tests.

RESULTS

Among all SRCs (n = 9542), headache (94.5%), dizziness (73.8%), and difficulty concentrating (56.0%) were commonly reported symptoms. On average, 4.7 ± 2.4 symptoms were reported per SRC. Overall, 51.3% had symptoms resolve in <7 d, yet only 7.9% had RTP < 7 d. Differential prevalence of amnesia was seen between practice and competition-related SRCs (8.8% vs 13.0%; P < .001); nonperson-contact and person-contact SRCs (9.3% vs 12.7%; P < .001); and female and male SRCs in low-contact sports (5.8% vs 17.5%; P < .001). Differential prevalence of loss of consciousness was seen between practice and game-related SRCs (1.3% vs 3.2%; P < .001); and female and male SRCs in high contact sports (1.2% vs 4.0%; P < .001). Differential longer SRT (>21 d) was seen between new and recurrent SRCs (9.4% vs 15.9%; P < .001).

CONCLUSION

Headache was the most commonly reported symptom. Notable group differences in the prevalence of amnesia, loss of consciousness, and SRT may be associated with more severe SRCs, warranting further attention.

Does disallowing body checking in non-elite 13- to 14-year-old ice hockey leagues reduce rates of injury and concussion? A cohort study in two Canadian provinces

OBJECTIVE

To compare rates of injury and concussion among non-elite (lowest 60% by division of play) Bantam (ages 13-14 years) ice hockey leagues that disallow body checking to non-elite Bantam leagues that allow body checking.

METHODS

In this 2-year cohort study, Bantam non-elite ice hockey players were recruited from leagues where policy allowed body checking in games (Calgary/Edmonton 2014-2015, Edmonton 2015-2016) and where policy disallowed body checking (Kelowna/Vancouver 2014-2015, Calgary 2015-2016). All ice hockey game-related injuries resulting in medical attention, inability to complete a session and/or time loss from hockey were identified using valid injury surveillance methodology. Any player suspected of having concussion was referred to a study physician for diagnosis and management.

RESULTS

49 body checking (608 players) and 33 non-body checking teams (396 players) participated. There were 129 injuries (incidence rate (IR)=7.98/1000 hours) and 54 concussions (IR=3.34/1000 hours) in the body checking teams in games. After policy change, there were 31 injuries (IR=3.66/1000 hours) and 17 concussions (IR=2.01/1000 hours) in games. Policy disallowing body checking was associated with a lower rate of all injury (adjusted incidence rate ratio (IRR)=0.44; 95% CI: 0.27 to 0.74). The point estimate showed a lower rate of concussion (adjusted IRR=0.6; 95% CI: 0.31 to 1.18), but this was not statistically significant.

CONCLUSION

Policy change disallowing body checking in non-elite Bantam ice hockey resulted in a 56% lower rate of injury. There is growing evidence that disallowing body checking in youth ice hockey is associated with fewer injuries.

The Effect of Body Checking Policy Changes on Concussion Incidence in Canadian Male Youth Ice Hockey Players: A Critically Appraised Topic

Clinical Scenario: Current studies have identified body checking as the most common cause of sports-related concussion in ice hockey across all divisions and levels. As a result, many hockey organizations, particularly in youth sports, have implemented rules making body checking to the head, face, and/or neck illegal. Such a rule, in Canada, makes age 13 the first age in which individuals can engage in body checking. Despite these changes, effectiveness of their implementation on the incidence of concussion in Canadian male youth ice hockey players remains unclear. Clinical Question: What is the effect of body checking policy changes on concussion incidence in male youth ice hockey players? Summary of Key Findings: Of the 3 included studies, 2 studies reported a decrease in the incidence of concussion once a body checking policy change was implemented. The third study showed an increase; however, it is important to note that this may be due, in part, to increased awareness leading to better reporting of injuries. Clinical Bottom Line: Current evidence supports a relationship between body checking policy implementation and decreased concussion incidence; however, more research is needed to understand the long-term implications of policy change and the effects in other leagues. In addition, further data are needed to differentiate between increased concussion incidence resulting from concussion education efforts that may improve disclosure and increased concussion incidence as a direct result of policy changes. Strength of Recommendation: Grade B evidence exists that policy changes regarding body checking decrease concussion incidence in male youth ice hockey players.

The First Decade of Web-Based Sports Injury Surveillance: Descriptive Epidemiology of Injuries in US High School Boys' Ice Hockey (2008-2009 Through 2013-2014) and National Collegiate Athletic Association Men's and Women's Ice Hockey (2004-2005 Through 2013-2014)

CONTEXT

Web-based sports injury surveillance via programs such as the High School Reporting Information Online system and the National Collegiate Athletic Association Injury Surveillance Program has aided efforts to collect data on ice hockey injuries.

OBJECTIVE

To describe the epidemiology of injuries sustained in high school boy's ice hockey in the 2008-2009 through 2013-2014 academic years and collegiate men's and women's ice hockey in the 2004-2005 through 2013-2014 academic years using Web-based surveillance.

DESIGN

Descriptive epidemiology study.

SETTING

Online injury surveillance of ice hockey teams of high school boys (annual average = 34), collegiate men (annual average = 20), and collegiate women (annual average = 11).

PATIENTS OR OTHER PARTICIPANTS

Boys', men's, and women's ice hockey players who participated in practices and competitions during the 2008-2009 through 2013-2014 high school academic years or the 2004-2005 through 2013-2014 collegiate academic years.

MAIN OUTCOME MEASURE(S)

Athletic trainers collected time-loss (≥24 hours) injury and exposure data. We calculated injury rates per 1000 athlete-exposures (AEs), injury rate ratios (IRRs) with 95% confidence intervals (CIs), and injury proportions by body site and diagnosis.

RESULTS

The High School Reporting Information Online system documented 831 boys' ice hockey time-loss injuries during 356 997 AEs; the National Collegiate Athletic Association Injury Surveillance Program documented 2611 men's ice hockey time-loss injuries during 552 642 AEs and 752 women's ice hockey injuries during 232 051 AEs. Injury rates were higher in collegiate men than in high school boys during 2008-2009 through 2013-2014 (4.38 versus 2.33/1000 AEs; IRR = 1.88; 95% CI = 1.73, 2.05) and collegiate women during 2004-2005 through 2013-2014 (IRR = 1.46; 95% CI = 1.34, 1.58). Most injuries occurred during competitions (boys = 80.0%, men = 66.9%, women = 55.3%); injury rates were higher in competitions than in practices for boys (IRR = 8.14; 95% CI = 6.87, 9.65), men (IRR = 6.58; 95% CI = 6.06, 7.13), and women (IRR = 3.63; 95% CI = 3.14, 4.19). At all levels, most injuries occurred to the head/face and shoulder/clavicle and resulted in concussions, contusions, or ligament sprains.

CONCLUSIONS

Injury rates varied across sports but were consistently higher in competitions than in practices. In competitions, concussions were common injuries, highlighting the need for continued development of injury-prevention strategies.

American Medical Society for Sports Medicine Position Statement on Concussion in Sport

Sport-related concussion (SRC) is a common injury in recreational and organized sport. Over the past 30 years, there has been significant progress in our scientific understanding of SRC, which in turn has driven the development of clinical guidelines for diagnosis, assessment, and management of SRC. In addition to a growing need for knowledgeable health care professionals to provide evidence-based care for athletes with SRC, media attention and legislation have created awareness and, in some cases, fear about many issues and unknowns surrounding SRC. The American Medical Society for Sports Medicine formed a writing group to review the existing literature on SRC, update its previous position statement, and address current evidence and knowledge gaps regarding SRC. The absence of definitive outcomes-based data is challenging and requires relying on the best available evidence integrated with clinical experience and patient values. This statement reviews the definition, pathophysiology, and epidemiology of SRC, the diagnosis and management of both acute and persistent concussion symptoms, the short- and long-term risks of SRC and repetitive head impact exposure, SRC prevention strategies, and potential future directions for SRC research. The American Medical Society for Sports Medicine is committed to best clinical practices, evidence-based research, and educational initiatives that positively impact the health and safety of athletes.

What the research says about concussion risk factors and prevention strategies for youth sports: A scoping review of six commonly played sports

INTRODUCTION

Given the growing research on potential adverse outcomes related to concussion and other serious brain injuries and the increased susceptibility for concussion among youth athletes, primary prevention is vital to protect the health and safety of this population. The purpose of this study is to summarize the current research on risk factors and primary concussion prevention strategies focused on specific youth sports, and to identify research gaps.

METHODS

A literature search was conducted using six electronic databases. A scoping review method was used to identify studies that addressed risk factors or primary concussion prevention strategies focused on youth athletes (ages 5-18 years) in six sports (football, ice hockey, soccer, lacrosse, basketball, and wrestling).

RESULTS

Of the 18 publications identified, the publications focused on risk factors (N = 11), policy (N = 1), rule changes (N = 3), education (N = 2), equipment (N = 2), and playing technique (N = 0). Some articles had information related to multiple topics.

CONCLUSIONS

Current research on concussion prevention has primarily been focused on risk factors. There are a dearth of studies that examine primary concussion prevention in sports. When studies do exist, most focus on football and ice hockey. Only a small number of studies focus solely on risk factors or primary prevention in soccer, lacrosse, basketball, and wrestling-all sports in which concussions are common. Practical applications: This scoping review summarizes current research on concussion risk factors and primary prevention strategies in specific sports focused on youth athletes and identifies research gaps to help inform future efforts.

American Medical Society for Sports Medicine position statement on concussion in sport

Sport-related concussion (SRC) is a common injury in recreational and organised sport. Over the past 30 years, there has been significant progress in our scientific understanding of SRC, which in turn has driven the development of clinical guidelines for diagnosis, assessment and management of SRC. In addition to a growing need for knowledgeable healthcare professionals to provide evidence-based care for athletes with SRC, media attention and legislation have created awareness and, in some cases, fear about many issues and unknowns surrounding SRC. The American Medical Society for Sports Medicine (AMSSM) formed a writing group to review the existing literature on SRC, update its previous position statement, and to address current evidence and knowledge gaps regarding SRC. The absence of definitive outcomes-based data is challenging and requires relying on the best available evidence integrated with clinical experience and patient values. This statement reviews the definition, pathophysiology and epidemiology of SRC, the diagnosis and management of both acute and persistent concussion symptoms, the short-term and long-term risks of SRC and repetitive head impact exposure, SRC prevention strategies, and potential future directions for SRC research. The AMSSM is committed to best clinical practices, evidence-based research and educational initiatives that positively impact the health and safety of athletes.

Primary prevention of contact sports-related concussions in amateur athletes: a systematic review from the Eastern Association for the Surgery of Trauma

BACKGROUND

Awareness of the magnitude of contact sports-related concussions has risen exponentially in recent years. Our objective is to conduct a prospectively registered systematic review of the scientific evidence regarding interventions to prevent contact sports-related concussions.

METHODS

Using the Grading of Recommendations Assessment, Development, and Evaluation methodology, we performed a systematic review of the literature to answer seven population, intervention, comparator, and outcomes (PICO) questions regarding concussion education, head protective equipment, rules prohibiting high-risk activity and neck strengthening exercise for prevention of contact sports-related concussion in pediatric and adult amateur athletes. A query of MEDLINE, PubMed, Scopus, Cumulative Index of Nursing and Allied Health Literature, and Embase was performed. Letters to the editor, case reports, book chapters, and review articles were excluded, and all articles reviewed were written in English.

RESULTS

Thirty-one studies met the inclusion criteria and were applicable to our PICO questions. Conditional recommendations are made supporting preventive interventions concussion education and rules prohibiting high-risk activity for both pediatric and adult amateur athletes and neck strengthening exercise in adult amateur athletes. Strong recommendations are supported for head protective equipment in both pediatric and adult amateur athletes. Strong recommendations regarding newer football helmet technology in adult amateur athletes and rules governing the implementation of body-checking in youth ice hockey are supported.

CONCLUSION

Despite increasing scientific attention to sports-related concussion, studies evaluating preventive interventions remain relatively sparse. This systematic review serves as a call to focus research on primary prevention strategies for sports-related concussion.

LEVEL OF EVIDENCE

IV.

PROSPERO REGISTRATION NUMBER

#42016043019.

A fluidics-based impact sensor

Microelectromechanical systems (MEMS)-based high-performance accelerometers are ubiquitously used in various electronic devices. However, there is an existing need to detect physical impacts using low-cost devices with no electronic circuits or a battery. We designed and fabricated an impact sensor prototype using a commercial stereolithography apparatus that only consists of a plastic housing and working fluids. The sensor device responds to the instantaneous acceleration (impact) by deformation and pinch off of a water droplet that is suspended in oil in a sensor cavity. We tested the various geometrical and physical parameters of the impact sensor to identify their relations to threshold acceleration values. We show that the state diagram that is plotted against the dimensionless Archimedes and Bond numbers adequately describes the response of the proposed sensor.

Cervical spine trauma: prevention strategies

Participation in any sport activity carries risk of cervical spine trauma, but certain activities have a higher risk than others, and hence, demand concerted efforts in developing prevention strategies. Prevention often includes efforts surrounding education of stakeholders, creating or modifying rules, and specific policies adopted for decreasing such risk. Stakeholders include sport clinicians, participants, coaches, parents, league administrators, officials, and the public. Thus, both athlete-specific and setting-specific factors must be considered and controlled to the extent possible for a multipronged approach for decreasing cervical spine injury risk. The effectiveness of certain strategies put into place in collision sports, such as American football, rugby, and ice hockey, is reviewed to illustrate this approach. Some research evidence exists that either has informed a strategy, or validated its effectiveness after the fact. More research of a higher level needs to be conducted in all sports to continue to contain the risk of cervical spine trauma to the fullest extent possible.

Traumatic brain injuries in mixed martial arts: A systematic review

Introduction

Mixed martial arts is an emerging combat sport that is gaining popularity worldwide. We systematically reviewed the literature regarding the prevalence, severity and risk factors of head injuries sustained in mixed martial arts activities.

Methods

We conducted a comprehensive systematic review of Ovid MEDLINE, Embase, PsycINFO, EBM Reviews, CINAHL, SPORTDiscus, and Web of Science from 1990 to 2016 for studies of any design that reported associations of acute or chronic head injuries in persons participating in mixed martial arts activities.

Results

The initial database search yielded a total 472 citations, including 264 unique citations after duplications were removed. A total of 18 articles, primarily of observational data, showed ‘technical knockouts’ and ‘knockouts’ are prevalent in this sport (range: 28.3–46.2% of all matches) with other studies showing the lifetime average of 6.2 technical knockouts or knockouts in a career. Studies used inconsistent reporting methods for concussion, and no information regarding long-term follow-up was available.

Conclusion

Mixed martial arts fighting may be associated with repetitive head injuries and potential long-term neurological consequences; however, data on this topic are poor. Larger studies and stringent medical oversight are needed to improve the management and understanding of mixed martial arts head injuries, with implementation of harm reduction strategies and/or rule modifications to prevent long-term neurological sequelae. Systematic Review Registration: PROSPERO – CRD42014010019.