Proceedings from the ice hockey summit on concussion: a call to action

National Hockey League Fights per Game and Viewership Trends: 2000-2020

Background

Though once considered an integral part of professional hockey, fighting carries significant health risks to players. Fighting has remained legal in the National Hockey League (NHL) due to its purported economic and entertainment value. However, fights per game have diminished over the past 20 years, challenging the necessity of fighting to promote fan attendance.

Hypothesis

Despite decreasing fighting rates, attendance has been stable and is negatively associated with fights per game.

Methods

Two public databases were reviewed to determine attendance, fighting majors, goals scored, and games played for each NHL team from 2000 to 2020 and averaged on a per game basis. Univariate analysis was used to evaluate relationships between attendance and fights, attendance and goals, as well as goals and fights.

Results

Fights per game decreased from a peak of 0.64 in 2002 to a low of 0.18 in 2020, while average attendance increased from a low of 16,549 in 2004 to a peak of 17,768 in 2013, before settling between 17,400 and 17,500 during the final three seasons of the study period. A significant negative correlation was found between attendance and fights per game (R = -0.6617, p = 0.0020). There was a positive, but not significant correlation between attendance and goals per game (R = 0.2457, p = 0.3105). A significant inverse correlation existed between goals per game and fights per game (R = -0.521, p = 0.0222).

Conclusions

NHL fighting rates have diminished during the past two decades, while fan attendance has increased. A significant negative correlation exists between fan attendance and fights per game, casting doubt on fighting's entertainment value. Meanwhile, a significant inverse correlation was noted between goals per game and fights per game. Taken together, these findings suggest fans may prefer higher scoring and less violent competitions. We conclude by suggesting that prohibiting fights in the NHL could improve player safety without negatively impacting fan attendance.

Proceedings From the Ice Hockey Summit III: Action on Concussion

OBJECTIVES

The Ice Hockey Summit III provided updated scientific evidence on concussions in hockey to inform these 5 objectives: (1) describe sport related concussion (SRC) epidemiology; (2) classify prevention strategies; (3) define objective, diagnostic tests; (4) identify treatment; and (5) integrate science and clinical care into prioritized action plans and policy.

METHODS

Our action plan evolved from 40 scientific presentations. The 155 attendees (physicians, athletic trainers, physical therapists, nurses, neuropsychologists, scientists, engineers, coaches, and officials) voted to prioritize these action items in the final Summit session.

RESULTS

To (1) establish a national and international hockey database for SRCs at all levels; (2) eliminate body checking in Bantam youth hockey games; (3) expand a behavior modification program (Fair Play) to all youth hockey levels; (4) enforce game ejection penalties for fighting in Junior A and professional hockey leagues; (5) establish objective tests to diagnose concussion at point of care; and (6) mandate baseline testing to improve concussion diagnosis for all age groups.

CONCLUSIONS

Expedient implementation of the Summit III prioritized action items is necessary to reduce the risk, severity, and consequences of concussion in the sport of ice hockey.

Epidemiology of Injuries in Ice Hockey

CONTEXT

Hockey is a skillful contact sport with an elevated injury risk at higher levels of play. An understanding of injury incidence, type, mechanism, and severity at various levels of competition aids the clinician treating these athletes. The purpose of this clinical review is to discuss the epidemiology of hockey injuries at various levels of participation, including youth, high school, junior, college, and professional.

EVIDENCE ACQUISITION

A literature search was performed by a review of PubMed, Embase, and Cochrane databases and included articles published from 1988 to 2017. Studies were included in this review if determined to be of high quality and containing injury data relevant to the levels of competition. Pertinent data regarding ice hockey injury epidemiology and prevention at various levels of competition were analyzed.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Youth, high school, junior, college, and professional hockey players have unique injury patterns. Injuries occur much more often in a game compared with a practice, and injury risk increases with each level of competition. Preventative measures, such as mandatory facial protection and delayed body checking in games until age 13 years, are proven strategies to reduce the risk of facial injury and concussion.

CONCLUSION

An understanding of common injury types and mechanisms according to age and level of play aids the clinician in diagnosis and management. This information can also guide preventative strategies in the areas of education, coaching, rule enforcement, rule modifications, equipment improvement, and sportsmanship.

Effect of Penalty Minute Rule Change on Injuries and Game Disqualification Penalties in High School Ice Hockey

BACKGROUND

Recent efforts have focused on eliminating dangerous hits in ice hockey. Fair play rule changes have successfully reduced injury risk but have not been widely implemented.

PURPOSE

To determine the effect of a penalty infraction minutes (PIM) rule change in high school boys' ice hockey on injuries and game disqualification penalties.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Injury data were collected from 2 Rhode Island hospital systems and game/penalty data through the Rhode Island Hockey Coaches Association website. Participants included high school boys' hockey varsity players aged 13 to 19 years presenting to 5 emergency departments for hockey injuries during 6 seasons (December 2012-April 2018). Rule change for the 2015-2016 season implemented varying suspensions for players accumulating ≥50 PIM and ≥70 PIM during regular season and playoffs. Injuries were classified as body checking or non-body checking related, and injury rates pre- versus post-rule change were compared via the Cochran-Mantel-Haenszel chi-square test with the odds ratio (OR) to measure risk reduction.

RESULTS

During the study period, 1762 boys' high school varsity hockey games were played. Of 134 game-related injuries, 82 (61.2%) were attributable to body checking. The PIM rule change was associated with a significant reduction in all injuries (OR, 0.55; 95% CI, 0.35-0.86; P = .008), concussion/closed head injury (OR, 0.44; 95% CI, 0.23-0.85; P = .012), and combined subgroups of concussion/closed head injury and upper body injury (OR, 0.50; 95% CI, 0.31-0.80; P = .003). Game disqualification penalties per season were not significantly reduced following the rule change, occurring in 5.2% of games before the rule change and 4.4% of games after (OR, 0.84; 95% CI, 0.54-1.31; P = .440).

CONCLUSION

Implementation of a statewide PIM restriction rule change effectively reduced the mean number of game-related injuries per season among high school boys' hockey varsity players.

Proceedings from the Ice Hockey Summit III: Action on Concussion

The Ice Hockey Summit III provided updated scientific evidence on concussions in hockey to inform these five objectives: 1) describe sport-related concussion (SRC) epidemiology, 2) classify prevention strategies, 3) define objective, diagnostic tests, 4) identify treatment, and 5) integrate science and clinical care into prioritized action plans and policy. Our action plan evolved from 40 scientific presentations. The 155 attendees (physicians, athletic trainers, physical therapists, nurses, neuropsychologists, scientists, engineers, coaches, and officials) voted to prioritize these action items in the final Summit session. 1) Establish a national and international hockey data base for SRC at all levels, 2) eliminate body checking in Bantam youth hockey games, 3) expand a behavior modification program (Fair Play) to all youth hockey levels, 4) enforce game ejection penalties for fighting in Junior A and professional hockey leagues, 5) establish objective tests to diagnose concussion at point of care (POC), and 6) mandate baseline testing to improve concussion diagnosis for all age groups. Expedient implementation of the Summit III prioritized action items is necessary to reduce the risk, severity, and consequences of concussion in the sport of ice hockey.

Youth Sport-Related Concussions: Perceived and Measured Baseline Knowledge of Concussions Among Community Coaches, Athletes, and Parents

OBJECTIVE

To assess concussion knowledge of athletes, coaches, and parents/guardians in a community setting and to understand trends/gaps in knowledge among subgroups to tailor efforts toward creating educational interventions.

PARTICIPANTS AND METHODS

This prospective cross-sectional study involved 262 individuals (142 [55%] female): 115 athletes participating in noncontact and contact sports (ages 13-19 years), 15 coaches, and 132 parents. Recruitment occurred from August 30, 2015, through August 30, 2016, at 3 local high schools. Participants completed a questionnaire developed by the investigators to assess concussion experience and basic knowledge.

RESULTS

Females, health care employees, and parents showed stronger concern for potential long-term sequelae of concussion, whereas athletes were most concerned about not being able to return to sport. Those with higher perceived concussion knowledge were slightly older (median age, 42.5 vs 33 years), more educated (college or higher: 42 [70%] vs 100 [50%]), and more likely to be health care workers (22 [37.9%] vs 34 [17.7%]) and scored higher on knowledge questions (average correct: 75.5% vs 60%). Most participants could identify potential concussion sequelae, but only 86 (34.3%) identified a concussion as a brain injury. Of the subgroups, coaches scored highest on knowledge questions. Those with a concussion history tended to consider themselves more knowledgeable but were also less concerned about sequelae. Overall, those with a concussion history scored slightly higher on knowledge questions (average correct: 69.8% vs 61.9%). Participants involved in contact sports were more likely to have had a concussion vs those in noncontact sports (57 [26%] vs 4 [10.3%]).

CONCLUSION

Significant differences in perceived and actual concussion knowledge across different subgroups of study participants involved in high school sports were identified.

Concussion in Ice Hockey: Current Gaps and Future Directions in an Objective Diagnosis

OBJECTIVE

This review provides an update on sport-related concussion (SRC) in ice hockey and makes a case for changes in clinical concussion evaluation. Standard practice should require that concussions be objectively diagnosed and provide quantitative measures of the concussion injury that will serve as a platform for future evidence-based treatment.

METHODS

The literature was surveyed to address several concussion-related topics: research in ice hockey-related head trauma, current subjective diagnosis, promising components of an objective diagnosis, and current and potential treatments.

MAIN RESULTS

Sport-related head trauma has marked physiologic, pathologic, and psychological consequences for athletes. Although animal models have been used to simulate head trauma for pharmacologic testing, the current diagnosis and subsequent treatment in athletes still rely on an athlete's motivation to report or deny symptoms. Bias-free, objective diagnostic measures are needed to guide quantification of concussion severity and assessment of treatment effects. Most of the knowledge and management guidelines of concussion in ice hockey are generalizable to other contact sports.

CONCLUSIONS

There is a need for an objective diagnosis of SRC that will quantify severity, establish a prognosis, and provide effective evidence-based treatment. Potential methods to improve concussion diagnosis by health care providers include a standardized concussion survey, the King-Devick test, a quantified electroencephalogram, and blood analysis for brain cell-specific biomarkers.

Evaluation, management and prevention of lower extremity youth ice hockey injuries

Ice hockey is a fast-paced sport played by increasing numbers of children and adolescents in North America and around the world. Requiring a unique blend of skill, finesse, power and teamwork, ice hockey can become a lifelong recreational activity. Despite the rising popularity of the sport, there is ongoing concern about the high frequency of musculoskeletal injury associated with participation in ice hockey. Injury rates in ice hockey are among the highest in all competitive sports. Numerous research studies have been implemented to better understand the risks of injury. As a result, rule changes were adopted by the USA Hockey and Hockey Canada to raise the minimum age at which body checking is permitted to 13–14 years (Bantam level) from 11–12 years (Pee Wee). Continuing the education of coaches, parents and players on rules of safe play, and emphasizing the standards for proper equipment use are other strategies being implemented to make the game safer to play. The objective of this article was to review the evaluation, management and prevention of common lower extremity youth hockey injuries.

Safe-Play Knowledge, Aggression, and Head-Impact Biomechanics in Adolescent Ice Hockey Players

CONTEXT

Addressing safe-play knowledge and player aggression could potentially improve ice hockey sport safety.

OBJECTIVES

To compare (1) safe-play knowledge and aggression between male and female adolescent ice hockey players and (2) head-impact frequency and severity between players with high and low levels of safe-play knowledge and aggression during practices and games.

DESIGN

Cohort study.

SETTING

On field.

PATIENTS OR OTHER PARTICIPANTS

Forty-one male (n = 29) and female (n = 12) adolescent ice hockey players.

INTERVENTION(S)

Players completed the Safe Play Questionnaire (0 = less knowledge, 7 = most knowledge) and Competitive Aggressiveness and Anger Scale (12 = less aggressive, 60 = most aggressive) at midseason. Aggressive penalty minutes were recorded throughout the season. The Head Impact Telemetry System was used to capture head-impact frequency and severity (linear acceleration [g], rotational acceleration [rad/s(2)], Head Impact Technology severity profile) at practices and games.

MAIN OUTCOME MEASURE(S)

One-way analyses of variance were used to compare safe play knowledge and aggression between sexes. Players were categorized as having high or low safe-play knowledge and aggression using a median split. A 2 × 2 mixed-model analysis of variance was used to compare head-impact frequency, and random-intercept general linear models were used to compare head-impact severity between groups (high, low) and event types (practice, game).

RESULTS

Boys (5.8 of 7 total; 95% confidence interval [CI] = 5.3, 6.3) had a trend toward better safe-play knowledge compared with girls (4.9 of 7 total; 95% CI = 3.9, 5.9; F1,36 = 3.40, P = .073). Less aggressive male players sustained significantly lower head rotational accelerations during practices (1512.8 rad/s (2) , 95% CI = 1397.3, 1637.6 rad/s(2)) versus games (1754.8 rad/s (2) , 95% CI = 1623.9, 1896.2 rad/s(2)) and versus high-aggression players during practices (1773.5 rad/s (2) , 95% CI = 1607.9, 1956.3 rad/s (2) ; F1,26 = 6.04, P = .021).

CONCLUSIONS

Coaches and sports medicine professionals should ensure that athletes of all levels, ages, and sexes have full knowledge of safe play and should consider aggression interventions for reducing head-impact severity among aggressive players during practice.

Does fair play reduce concussions? A prospective, comparative analysis of competitive youth hockey tournaments

Background/aim

To determine if Boys Bantam and Peewee and Girls U14 sustain fewer concussions, head hits, ‘other injuries’ and penalties in hockey tournaments governed by intensified fair play (IFP) than non-intensified fair play (NIFP).

Methods

A prospective comparison of IFP, a behaviour modification programme that promotes sportsmanship, versus control (non-intensified, NIFP) effects on numbers of diagnosed concussions, head hits without diagnosed concussion (HHWDC), ‘other injuries’, number of penalties and fair play points (FPPs). 1514 players, ages 11–14 years, in 6 IFP (N=950) and 5 NIFP (N=564) tournaments were studied.

Results

Two diagnosed concussions, four HHWDC, and six ‘other injuries’ occurred in IFP tournaments compared to one concussion, eight HHWDC and five ‘other injuries’ in NIFP. There were significantly fewer HHWDC in IFP than NIFP (p=0.018). However, diagnosed concussions, ‘other injuries’, penalties and FPPs did not differ significantly between conditions. In IFP, a minority of teams forfeited the majority of FPPs. Most diagnosed concussions, HHWDC, and other injuries occurred to Bantam B players and usually in penalised teams that forfeited their FPPs.

Conclusions

In response to significant differences in HHWDC between IFP and NIFP tournaments, the following considerations are encouraged: mandatory implementation of fair play in regular season and tournaments, empowering tournament directors to not accept heavily penalised teams, and introducing ‘no body checking’ in Bantam.

Concussion in the National Hockey League: a systematic review of the literature

Players in the National Hockey League (NHL) are often sidelined by injuries, including concussion. The acute, intermediate and long-term effects of repetitive head trauma remain a concern of many. In 1997, the NHL and NHL Players Association established the NHL-NHL Players Association Concussion Program to diagnose, assess and treat concussion via a standardized and scientific approach. Documenting and analyzing the trends, incidence and underlying mechanisms of concussion may help in devising future prevention and treatment plans for concussion in hockey in general and the NHL in particular. The purpose of this study, therefore, was to systematically review and summarize the existing published literature on the trends, incidence rates and underlying mechanisms of concussion in the NHL.

Ice Hockey Summit II: zero tolerance for head hits and fighting

OBJECTIVE

To present currently known basic science and on-ice influences of sport-related concussion (SRC) in hockey, building on the Ice Hockey Summit I action plan (2011) to reduce SRC.

METHODS

The prior summit proceedings included an action plan intended to reduce SRC. As such, the proceedings from Summit I served as a point of departure, for the science and discussion held during Summit II (Mayo Clinic, Rochester MN, October 2013). Summit II focused on (1) Basic Science of Concussions in Ice Hockey: Taking Science Forward; (2) Acute and Chronic Concussion Care: Making a Difference; (3) Preventing Concussions via Behavior, Rules, Education and Measuring Effectiveness; (4) Updates in Equipment: their Relationship to Industry Standards; and (5) Policies and Plans at State, National and Federal Levels to reduce SRC. Action strategies derived from the presentations and discussion described in these sectors were subsequently voted on for purposes of prioritization. The following proceedings include knowledge and research shared by invited faculty, many of whom are health care providers and clinical investigators.

RESULTS

The Summit II evidence-based action plan emphasizes the rapidly evolving scientific content of hockey SRC. It includes the most highly prioritized strategies voted on for implementation to decrease concussion.

CONCLUSIONS

The highest priority action items identified from the Summit includes the following: (1) eliminate head hits from all levels of ice hockey, (2) change body-checking policies, and (3) eliminate fighting in all amateur and professional hockey.

Postconcussion symptoms are associated with cerebral cortical thickness in healthy collegiate and preparatory school ice hockey players

OBJECTIVE

To investigate the degree to which concussion history and postconcussive symptoms are associated with cortical morphology among male hockey players.

STUDY DESIGN

Male subjects (n = 29), ranging in age from 14 to 23 years (mean 17.8 years), were recruited from preparatory school and collegiate ice hockey teams and underwent neuroimaging and baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) testing. Cerebral cortical thickness was regressed against ImPACT Total Symptom Score (TSS), concussion history, as well as baseline measures of psychopathology. Reconstruction of surfaces and cortical thickness analysis were conducted with FreeSurfer (version 5.3.0).

RESULTS

ImPACT TSS was inversely associated with local cortical thickness in widespread brain areas. Associations were revealed in a host of frontal as well as bilateral temporoparietal cortices. Conversely, concussion history was not associated with cortical thickness. An "Age by Concussion History" interaction was associated with thickness in the right ventrolateral and right parietal cortices. Post-hoc analysis revealed that concussed participants did not exhibit age-related cortical thinning in these regions.

CONCLUSION

We have identified an association between brain structure and postconcussive symptoms among young, otherwise-healthy male athletes. Postconcussive symptoms and related reductions in cortical thickness may be tied to participation in a full-contact sport that involves frequent blows to the head.

Modifying factors in sports-related concussion: dangerous style of play

In its third iteration, the Concussion in Sport Group identified 10 modifying factors that were presumed clinically to influence the investigation and management of concussions in sports. "Dangerous style of play" was delineated as one of these factors, most likely based on clinical lore. These modifying factors were retained in a more recent Concussion in Sport Group statement. To date, there has been no concerted effort to support or refute the inclusion of this constellation of behaviors as a modifying factor in sports-related concussion. This article reviews and summarizes the limited evidence related to a dangerous style of play in sports-related concussion, offers a preliminary assessment of its relevance as a modifying factor, and provides additional information on other aspects of player, coach, and governing body behavior and their potential effect(s) on reducing concussive injuries.