University study on concussions raises questions about athlete safety
Researchers at the University of Michigan are aiming to make progress toward encouraging safer equipment for athletes and raising awareness about common brain injuries that can occur on the field — an issue of rising concern in both professional and college sports — through new helmet technology.
A new sports-helmet prototype capable of dissipating impulse from impact and taking kinetic energy away from the skull and brain while playing high-contact sports is being developed by a team in the College of Engineering. Though helmets currently used for sports like football are intended to protect against skull and brain injuries, this new prototype aims to step beyond that with new understandings about how the brain becomes injured.
Co-author of the study Ellen Arruda, a professor of mechanical engineering, said the project began by looking at applying lightweight materials to the blast and impact associated with high-contact sports.
“It’s only recently that we’ve understood traumatic brain injuries,” Arruda said. “The helmets that we’re using weren’t designed to protect the brain; they were designed to prevent skull fracture … Now that we understand that they also have to protect the brain, we realized that literature had virtually no information on how to go about doing that … no one carefully looked at what it would take to optimally reduce the force and impulse of an impact in a helmet design over and over and over again.”
Arruda said she and her colleagues specifically researched football and were thus well prepared to try to initially develop the prototype helmet technology, called Mitigatium, for the Head Health Challenge III. This competition was created to encourage the development of materials that better absorb or dissipate harsh impact.
The prototype Arruda and her colleagues are developing has different capabilities than traditional football helmets already in use, the team said.
“It has the ability to dissipate impulse, or take kinetic energy out of the brain, (and) prevent it from being transferred to the brain,” Arruda said. “It does that by visco-elastically dampening the stress wave as it goes through the helmet.”
Co-author Michael Thouless, professor of mechanical engineering, said before beginning the prototype, the researchers worked together to look at the mechanics of impact and try to understand what aspects of the mechanics actually contribute to injury.
According to the NFL 2015 injury data report released in January 2016, in 2015 there were a total of 271 concussion incidences in both the preseason and regular season, with only 37 concussive injuries occurring during practice and 234 occurring during a game. This report indicates that 2015 holds the highest amount of concussions in the past four years. 2014, only one year before, held only 206 total incidences.
At the University, the question of how to handle concussions in athletes gained significant attention over now-former football coach Brady Hoke’s actions regarding then-sophomore quarterback Shane Morris’ concussion in the Sept. 27, 2014 game against Minnesota. Morris was involved in a hard head-on hit, yet continued to play despite what was later confirmed as a concussion.
Speculation arose that Hoke took the wrong steps in ensuring Morris’ safety and health for the sake of the game. Former University Athletic Director Dave Brandon spoke with the Daily following the incident in 2014 to discuss the importance of student-athlete health. Brandon resigned from the University soon after the incident. Hoke told media sources that he was unaware of Morris’ condition during the game.
University President Mark Schlissel later also released a statement, demonstrating concern for the health of student athletes and apologized to Morris, his family and his teammates for the way the situation was handled.
The incident, among others, led to the Big Ten moving to institute independent medical spotters during games.
Associate Kinesiology Prof. Steven Broglio said concussions can have a multitude of effects on any athlete. Broglio said concussions are typically seen as an alteration in mental status with or without loss of consciousness. He added that in many cases, symptoms include disorientation, feeling unbalanced or mental confusion. Because it is not possible to complete a CT scan, MRI or X-ray to determine if an athlete has a concussion, the diagnosis is purely based on clinical evaluation.
Oftentimes, Broglio said players might not report their injury in fear of having to leave the field.
“Certainly it’s an issue if (the athlete doesn’t) report their injury to a medical professional,” Broglio said. “Only about 10 percent of the (concussion) injuries result in a loss of consciousness, so it’s very easy to hide the injury if you’re an athlete.”
There are many cases in which the athlete continues to play during the game but reports their injury afterward, Broglio said. He said this might be because head injuries do not always result in concussions.
“(However), signs and symptoms can slowly develop and that can be anywhere from 40 minutes after the impact to days after the impact,” Broglio said. “Certainly athletes that continue to play after they’re concussed, if they chose not to report, they are going to prolong their recovery period. If an athlete is suspected of the injury, then they should be immediately removed from play and then evaluated by a trained professional.”
However, this does not necessarily happen as sports become more competitive, Broglio said.
Researchers Thouless and Arruda found that in the mechanics of a concussion, there are two parts of a hit that matter in determining medical outcome: the force and the impulse, which are both developed during an impact.
The first trial for the prototype only had to meet the Head Health Challenge’s entry requirements, Arruda said. Researchers dropped a weight on the prototype and measured the rebound height of that weight.
The testing Arruda and her colleagues are doing now uses a cylindrical prototype, to which they added a skull and brain surrogate using materials that are similar in mechanical properties to a real skull and brain, Arruda said. Using the cylindrical skull and brain, the researchers put layers of helmet material around it and allowed the prototype to roll.
Researchers then filmed the trial to observe the speckle pattern, which shows and measures strain on the brain on the surface of the brain, and saw how it stretched and deformed. They were then able to compare the calculations of their helmet design versus existing helmet designs.
Arruda and her colleagues are one of five finalists in the Head Health Challenge, to which they will send their refined version to compete by the end of the year. She said the researchers are currently focusing on finding the best combination of materials for optimal performance.
However, she noted that no matter what the outcome of the competition, she believed overall better technology needs to be put into helmets. Current helmets are easily cracked or broken during high-contact sports such as football, and producers of the equipment have not yet begun to reduce the force and impulse of an impact. As a result, helmets would ideally be replaced more often. However, this solution is not practical in the long-term, Arruda said.
“You can’t just stop the game after every impact where the helmet has been fractured and get a new one,” Arruda said. “It’s not only impractical from the standpoint from the flow of the game, it’s very costly. A strategy like that would probably never make it down to the little kids playing football who often don’t have very expensive helmets.”
Thouless agreed with Arruda, saying football helmets are unlike helmets used for activities such as riding a bike. If a person falls off their bike, his or her helmet likely cracks to dissipate the energy from the fall, and is replaced before the next use. With football and other high-contact sports, this is a less practical system.
In addition to better quality helmets, Broglio said he thought that to resolve the issue there was a need for better-defined rules in games such as football, hockey and lacrosse, stricter enforcement of them, harsher penalties for violating the rules and better education about concussions.
However, research in the field on the impact of concussions — and therefore, how they should be approached — remains contested.
In a presentation in December 2014 by Jeffrey Kutcher, the national director of the Sports Neurology Clinic, Kutcher addressed misconceptions about concussions, specifically the distinction between a concussion, post-concussion syndrome and chronic effects of playing sports. Kutcher was previously an associate professor of neurology at the University, director of the NeuroSport program and a Michigan football team physician.
Despite some findings, Kutcher said in an interview with the Daily on Sunday he believes there are many misconceptions about concussions even today, particularly an overemphasis on the concussion itself.
“The vast majority of these injuries do not result in any long-term problems,” Kutcher said.
Rather than being a progressive problem, Kutcher said in many cases potential effects might include having a one-time decrease in the brain’s ability to form cognitive tasks.
“(Long term effects are) not about how many times a concussion has occurred,” Kutcher said. “More, it’s about how many times that brain has experienced force … For each individual, there’s going to be the amount of force that will become problematic. We don’t know what really sets those thresholds, those levels, but we do know that it’s a multifactorial thing.”
In contrast, an article published in the International Journal of Psychophysiology, of which Broglio was a co-author, observed an association between the number of concussions resulting in a loss of consciousness and greater variability of reaction time in various tasks.
The study noted that its claims support similar findings done in previous research that has observed a relationship between concussive injury and impairments in cognitive tasks.
However, the study added, “further research is needed to better address the apparent importance of sensory and attentional demands for detecting concussion related deficits.”