Hard Knock Ice
CTE & Ice Hockey

Boston College players line up near the goal prior to a game against Boston University. Photo by Steve McGuire.

Jack McBain (11), Christopher Brown (10) and Oliver Wahlmstrom (18) prepare to take a face-off against Boston University. Photo by Steve McGuire.

Boston University's Cam Crotty (red) and Boston College's David Cotton (white), sending Cotton to the ice. Photo by Steve McGuire.

Boston College players line up near the goal prior to a game against Boston University. Photo by Steve McGuire.
Fighting in Hockey
Fighting is more closely associated with hockey than any other non-combat sport. The comedian Rodney Dangerfield communicated this relationship when he said, “I went to a fight the other night, and a hockey game broke out.”
While the Goodman, Gaetz and Meichenbaum study states, “Fighting was not a major cause of concussion,” pugilistic interactions are known to contribute to CTE — demonstrated in boxing culture in the 1920s — likely through subconcussive impacts.
It is worth noting that three of the professional hockey players that have been diagnosed with CTE — Bob Probert, Derek Boogaard and Reggie Fleming — were notable fighters in the NHL.
During the 2017-18 season, HockeyFights.com recorded 280 fights between players. That is the fewest fights in a single season since the site began compiling this data in 2000. The NHL has averaged 553.7 fights per season since the turn of the century.
Even if ice hockey officials found a way to eliminate fights altogether, a 2016 study has determined that that change alone could lead to more physically aggressive play. Gregory DeAngelo, Brad R. Humphreys and Imke Reimers published results that indicated that the number of hits in an NHL game are actually reduced for up to ten minutes following a fight. Without fighting, the study indicates, games would include a higher sustained level of hits.
A flurry of motion catches the eye behind the goal. The scraping of skates against ice is punctuated with the sharp click of a stick against rubber and a heavy thud of bodies hitting the boards. Red on white. The glass flexes, warping around the helmet pressed against the panes. Seven-thousand voices crescendo into a collective, “Oooo!” The puck skitters away, and the crowd’s attention follows.
Boston College’s junior forward David Cotton slips to the ice, his legs tangled up with Boston University’s Cam Crotty. Cotton shakes off the hit and chases the puck back up the ice.
This jarring hit was just one of many that Cotton, Crotty, and the other members of the Boston College and Boston University men’s ice hockey teams would endure that night.
Chronic traumatic encephalopathy (CTE) is perhaps the greatest villain in the modern era of the violent, contact-defined National Football League, but in the rink, where hard, repetitive contact is as much a part of the game as anything else, the conversation seems a little bit quieter.
I set out to answer three questions:
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How concerning is the CTE problem in ice hockey?
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How is the hockey community responding to the threat of CTE in the sport?
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How are top collegiate programs that funnel players into professional careers, like Boston College, dealing with an increased national focus on CTE?
How concerning is the CTE problem in hockey?
According to a study by Boston University’s CTE Center, CTE is a progressive degenerative brain disease that can be caused by repetitive brain trauma, brain trauma that can be either concussive or subconcussive, like the hit sustained by Cotton.
Head trauma, whether concussive or subconcussive, can happen anywhere on the ice, whether it be a collision between players or a player collision with the rink structures, as detailed in a 2001 study by David Goodman, Michael Gaetz and Daniel Meichenbaum that examined concussions in Canadian Amateur hockey.
Bert Lenz, the director of Sports Medicine for Olympic sports at Boston College, explained to me that repetitive head trauma is an accepted part of the game.
“In ice hockey, it’s—it’s part of the sport,” he said. He compared the game’s interactions to those of football, saying that impacts in hockey are less predictable than those in football because of the nature of the game.
“So, in football, you reset the pieces, and you do the play again. I don’t know what the rate is; there’s not a lot of action in football, but there’s a lot of resetting of plays,” he said, “So, that piece for football becomes repetitive trauma based on everything starts again in the exact same position. Hockey, you’ve got to get yourself caught, either with your head down coming across the ice or up against the boards and then you get hit. ... I think the resetting doesn’t make it as repetitive in hockey as it does in football.”
Zafonte went on to say that he worries for “all people who have significant long-term repetitive contact” but that “we don’t know who is at highest risk.”
At any rate, limiting the number or severity of hits, and thus the number of potential concussive or subconcussive hits, may contribute to slowing or reducing the disease in ice hockey players.
While the evidence seems to point toward CTE being a problem worthy of address in hockey, there is some pushback from the highest levels of the sport.
How is the hockey community responding to the threat of CTE in the sport?
In 2016, Gary Bettman, the commissioner of the NHL, denied that CTE was caused by concussions when responding to a series of inquiries by Sen. Richard Blumenthal of Connecticut. Bettman said, “The relationship between concussions and the asserted clinical symptoms of CTE remains unknown.”
Bettman doubled down, saying, “Ultimately, the most concerning aspect of the current public dialogue about concussions in professional sports (as well as youth sports) is the implicit premise that hundreds of thousands — if not millions — of individuals who have participated in contact sports at the high school, collegiate and/or professional levels are not only at a high level of risk for, but actually more than likely to develop, a degenerative, irreversible brain disease (i.e., C.T.E.), and that they should be informed as such.”
In 2018, Bettman continued his insistent denial that there was any link between CTE and ice hockey in an interview with WFAN Sports Radio. When pressed to respond to the study conducted by Boston University’s CTE Center, Bettman said, “Boston [University], they will tell you that as it relates to hockey, they don't have enough evidence to reach any conclusions, and they have told me that directly."
That claim was quickly refuted by Dr. Ann McKee, a neurologist with BU’s CTE Center, and Chris Nowinski, the chief executive of the Concussion Legacy Foundation in a response obtained by several sports media outlets, such as TSN: “... it is misleading for Mr. Bettman to say we haven’t reached any conclusions. The evidence clearly supports that CTE is associated with ice hockey play. Since that 2012 meeting with Mr. Bettman, the VA-BU-CLF [Veterans Affairs-Boston University-Concussion Legacy Foundation] research team has identified CTE in more ice hockey players, including four amateur hockey players, not all of whom had significant fighting exposure.”
It appears that Bettman's denial has not necessarily had a widespread effect on the hockey playing community. Denhartog says that the hockey community acknowledges that Bettman's comments are likely in the best interests of the team and the team owners, not in the best interests of the players. He also believes that the hockey community understands the existence of the problem in spite of Bettman's efforts to deny it.
I recently conducted a survey that gathered more than 200 responses from hockey players and fans on Twitter, Facebook and Reddit. In this survey, respondents with collegiate and/or semi-professional ice hockey experience were asked to communicate their perspective on the connection between the sport and CTE. The results indicated that the majority of the respondents that identified as collegiate or semi-professional hockey players saw CTE as a serious problem facing the game.
How is a top collegiate ice hockey program like Boston College dealing with an increased national focus on CTE?
A little over a month before the game against Boston University, I sat down with Lenz to talk about the CTE problem in hockey and how Boston College was addressing it.
Boston College falls under the jurisdiction of the Gameday Safety Ordinance, a measure proposed by Councilor Josh Zakim and signed into effect by Boston Mayor Marty Walsh in 2014.
This ordinance requires schools participating in Division I NCAA events to employ a neurotrauma consultant on call at all football, hockey and men’s lacrosse games held in the Boston area. This ordinance predates the NFL’s 2017 move to employ neurotrauma consultants at every game.
When asked about how protocols have changed at Boston College, Lenz said that not a lot changed as a result of the ordinance.
“I feel we were ahead of the curve,” he said, “and a lot of that goes to us already having football and being ahead of the curve on including our physicians. We had a team already available. We didn’t have a 'neurospecialist.' But we’ve had sports medicine-trained family medicine physicians that have the extra certification, the extra qualifications that come under that ordinance that allow you to have the proper coverage at football games, and our team physicians have always had that.”
One of the notable differences between the Gameday Safety Ordinance and the NFL’s recent rule change is that neurotrauma consultants are not required to be on-site during Boston collegiate sporting events and thus would not be able to identify a potentially serious head injury and stop play temporarily.
“So the individual has to report the symptoms. The NCAA pushes them, and they have to sign certain papers saying that they will report the symptoms. They still don’t report the symptoms. But they’ve all been educated way more than anyone who played 10 or 15 years ago.”
If the players will not protect themselves, and, as Denhartog noted, there seems to be a lack of understanding among coaches and referees, who is protecting these players?
I asked Zafonte if there was anything that sports organizations could be doing right now to address the problem of CTE and protect younger players.
His primary suggestion was to introduce rules-based changes to the sports. He pointed out that USA Hockey amended their rules in 2011 to outlaw hitting in youth leagues with players under thirteen years old.
“I think some of these things are being done,” he said. “I think USA hockey and changed the age of hitting for kids, early on at some time, understanding how we do that, and how we play the puck and what the optimal teaching scenarios are in limiting some elements of that early contact. And drawing up rules-based changes that accommodate for that is true.”
Similarly, Denhartog praised the hockey community for its efforts to ensure that equipment standards in youth hockey are working to protect players’ heads.
“Now what I feel was a step in the right direction was adding a helmet rule mandating all players require HECC approved helmets that are not expired (stickers on the back of helmets.) While a lot of gear can be passed down the plastic on helmets age and with newer tech to helmets this helps players by wearing gear designed to take hits better,” he said.
I asked Denhartog if he, as a referee and one of the closest observers of the sport had recommendations about changes that could be implemented immediately. He recommended that penalties for specific checks be made more severe in youth hockey to try and decrease some of the illegal checking that can be seen at the lower levels.
Denhartog also suggested that education in a different area could help reduce head injuries as hockey players move through their careers: technique.
“I firmly believe we need to find a way to teach some sort of hitting at an earlier age in a safe manner,” Denhartog said. “Finding a way maybe to teach hitting without the risks early on so players have a better way to separate a player from the puck without excessive punishment. Teaching things like rub down techniques by skating and guiding a player into the boards without a full on check could be extremely helpful in teaching proper hitting without punishment.”
As for the future of head injuries in ice hockey, “it’s hard to say,” according to Lenz, “because they still have so much more to study. … There’ s so much research for them to do.”
Lenz is right. Ice hockey does not have the same type of resetting as football, but the number of hits sustained during play is certainly repetitive.
As Lenz hinted at, hits are an important part of the game of ice hockey.
According to statistics compiled by Fox Sports, NHL players committed an average of 1.18 qualified hits per game during the 2017-18 season. A qualified hit is considered a valid check on a player who has possession of the puck. There are 82 games in an NHL season, and the average NHL career lasts five and a half seasons, according to RAM Financial Group data published by Bleacher Report. If a player averages 1.8 hits per game in an 82-game season for five seasons, he will average 400 qualified hits in his hockey career.
This number, 400 career hits, completely leaves out hits that do not hit the statistics books as “qualified.” Four hundred collisions would be the baseline statistic. Add to that the number of illegal hits, accidental collisions, player-rink collisions and fights (see sidebar) and that number can rise well over 500 career interactions that could be potentially be classified as concussive or subconcussive interactions.
Mitchell Denhartog, who has served as an ice hockey referee for 14 years, spoke with me about his experiences as one of the closest observers of the sport. He communicated to me that these hits can be a significant problem for ice hockey players:
"Easily one of the most often interaction in hockey would be checking in the game. The issue I tend to see is bad form or dangerous checks. These tend to arise from either poor hitting form or intent to punish a player for a variety of reasons."
While the number of career hits may seem insignificant, keep in mind that the medical community has not determined how many hits cause CTE or if there is a lower limit on the number or kinds of hits that can contribute to the disease.
Dr. Ross Zafonte, the chief of Physical Medicine and Rehabilitation at Massachusetts General Hospital, explained to me that the disease is extremely complex and that the severity or even the presentation of the disease’s symptoms could be dependent on “the density of exposure, the type of exposure, maybe one’s own genetics, maybe other medical co-factors, plus the changes that come from the pathology itself.”

Based on data collected between 10/23/18 and 12/8/18 by Steve McGuire. Visualization created in Tableau. Methodology detailed at the bottom of the page.
BC’s Concussion Protocol
According to Lenz, the protocol for dealing with a neurotraumatic incident is rather straightforward if the player self-identifies symptoms or is presenting with visible symptoms, but the situation gets stickier when the player does not self-identify.
“The NCAA pushes them, and they have to sign certain papers saying that they will report the symptoms. They still don’t report the symptoms. … It’s the kids that come back to the bench, you walk over say ‘are you alright,’ they look you in the eye, they say ‘everything’s fine.’ And then the biggest thing is revisiting them.”
According to Lenz, Boston College uses a five-day concussion protocol to ensure that players do not reaggravate or worsen a neurotraumatic injury.
“Once they’re symptom-free, there is a five-day return from the point they’re symptom-free, and during that day, after that 24 hour period after they’re symptom-free, they start a progressive climb towards return to play. It used to be ‘okay, you’re symptom-free today, go back to your sport.’ Those days have changed. Now, it’s a progressive, pretty much a full five day, return to a full practice and then hopefully a game the following week.”
Lenz could not comment on whether this is an NCAA-enforced progression or a Boston College-specific policy.
This would put the onus on the player, the coaching staff, the referees and any on-hand medical staff to make the call in the moment.
Denhartog related to me that placing this responsibility on the coaches and referees is potentially dangerous.
“If the player says they’re fine, the coach isn’t going to question that,” said Denhartog. He expressed that there is a need for better training among coaches and referees to be able to identify head injuries when they occur on the ice and address the problem.
As for the players, Lenz said that the college educates players for the purposes of making them responsible for their own injuries.
“As far as addressing the kind of media frenzy that in some cases this has become,” he said, “it’s a very important issue, concussions are real, educating the student-athletes on what the symptoms are, what the impact of them playing with symptoms becomes is one of the bigger pieces.”
Lenz continued by comparing CTE awareness to the rise in litigation against tobacco companies. According to Lenz, both smokers and professional hockey players 25 years ago were not properly educated about the potential effects of smoking and hockey, respectively, and the result was that these people were able to sue their respective industries successfully because of their declining health.
Then Lenz said something that caught me off guard.
“So I tell the guys, you have nothing, you have nowhere to go,” he said, “because, at this point, you’ve all been educated enough to know what a symptom is, what the symptoms are, and what the next step is going to be. You’re not going to have anyone to sue. You’ve got nowhere to go. So protect your heads now.”
At this point, it became clear to me that a significant amount of responsibility is on the players to address their own head trauma as a result of their actions on the ice. However, Lenz said that the gravity of the situation is sometimes not enough to get players to take that responsibility: