On Nov, 9th 2023 Carolina Panthers tight end Hayden Hurst took a violent blow to the head during a routine football play which resulted in his head hitting the ground. Hurst was slow to rise, but there was no medical staff rushing to his side. After all, these types of hits are normal in football and honestly, it’s only in slow motion that you see his head snap backwards to meet the ground at the end of the play. Hurst went directly to the medical tent, was cleared for play after passing all of the required concussion testing, and then returned to the field. However, the true repercussions of the incident became glaringly evident when Hurst "woke up" four hours later on the plane ride home, unable to recall the play or the subsequent four hours. He was later diagnosed with Post Traumatic Amnesia.
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The CTE Epidemic:
Whether you are watching from your living room couch or calling the plays on the sidelines, it's widely acknowledged that football, both at the college and NFL levels, exposes players to frequent and impactful headshots. The severity and long-term impact of these head injuries have received many headlines following advances in medical technologies that allowed Chronic Traumatic Encephalopathy (CTE) to be evaluated postmortem. CTEs are caused by repeated head injuries which result in the death of nerve cells in the brain. According to the Mayo Clinic, CTE isn’t caused by a single head injury, but rather repeated head injuries. CTEs have also been associated with second impact syndrome, which is when a second head injury occurs before the first injury has healed. Preventing the second injury can be a challenge because, as in the case of Hurst, the symptoms of the injury can gradually increase over time.
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The ability to quantify the cumulative brain damage sustained over time has instigated a shift in the collective culture of the NFL and has spurred innovation within the medical community.
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The Evolution of Football Safety:
Effectively preventing football-related brain injuries hinges on addressing and minimizing concussions. In 2022, the NFL reported an increase in concussions to 149 from 126 in 2021. The solution is two-fold; implementation of safety-related play rules and the improvement of play protective equipment. While executives in the NCAA and NFL were actively engaged in formulating and enforcing safety rules for the game, the medical and engineering communities simultaneously began enhancing protective equipment. The brain, housed within the skull and cushioned by cerebrospinal fluid, becomes susceptible to injuries like concussions during sudden changes in motion. When sudden changes in motion occur, the brain moves in the skull and causes injuries like concussions. Football-related head injuries can broadly be categorized into two types: linear and rotational forces. Linear forces act in straight lines, encompassing backward, forward, or sideways movements. Conversely, rotational forces, often deemed the most dangerous, induce the head to rotate around its center, resulting in shearing of brain tissues. Recent strides in biomechanical research have facilitated the quantification of forces required for injury, the impact of repeated forces, and the cumulative effects associated with them. So, now that researchers have this fresh insight, they've rolled up their sleeves to create test setups for repeatedly checking how well equipment performs.
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With a clear understanding of the forces in play and the thresholds for injury, the research and development community sprang into action. In 2019, the NFL introduced the "NFL Helmet Challenge," a $3 million competition aimed at sparking and funding accelerated innovation. Over two years, teams of engineers and biomaterials experts from various disciplines worked on developing their helmet prototypes. The top 3 teams were then given another $1.55 million in grants to move those helmets into production. Laboratory testing revealed that these helmets showed a 13% improvement over the top performing helmets currently worn in the NFL. Thanks to the skillset of these multidisciplinary teams, this was 4 times the improvement typically seen in new helmet designs.
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While lacking prior experience in the design of football helmets, the Canadian team, Kollide, brought a unique skill set to the table—they were well-versed in designing medical devices. They assembled four smaller companies with distinct expertise. These included specialists in 3D printing, medical implants, 3D scanning software, and a sports equipment company. This strategic fusion of diverse skills and a medical device mindset helped to craft their innovative approach to addressing the safety challenges in football. Their final design included a liner of the helmet that featured a breakthrough design that included 3D-printed mesh pads. The 3D-printed mesh structure consists of 95 pads, each with a mesh interior optimized to absorb and redirect impact energy. Because this liner is 3D-printed, it can be customized for each player based on a 3D scan of the player’s skull.
Revolutionizing Helmet Design:
Impressio, a Denver-based company, took a groundbreaking approach by utilizing liquid crystal elastomers to craft a material specifically designed for absorbing and dissipating energy. The choice of elastomers, known for their biomechanical properties, including effective shock absorption, has gained traction in applications like prosthetic implants. Impressio created a 3D-printed lattice structure made of liquid crystal elastomers. In the event of impact, the columns within this lattice structure undergo a controlled buckling process, efficiently absorbing and dissipating energy. Chis Yakacki, the company’s co-founder, said “So, we have this material that’s very soft, very comfortable, can form to your head. But when impacted, all those small molecular crystals will rotate, get rid of the energy and attenuate those accelerations experienced by the wearer,” said Yakacki.”1
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The last company included in the top 3 was Detroit-based Xenith. Xenith is no stranger to the football helmet arena and currently has one being used on the field. The NFL challenge offered them the financial backing to take their development to the next level. They decided to design a helmet that took all the tools at their disposal and make the best helmet possible. Their design incorporated a 3D-printed lattice liner, a collaborative effort with BASF, and an innovative variable stiffness shell for the exterior. But what really improved their performance was a polymeric material that fit between the liner and the shell. Crafted from reactive polymers, this material demonstrated dynamic properties based on the type of impact. For low-speed impacts, it exhibited soft and flexible characteristics, while for higher-speed impacts, it strengthens.
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A Personal Perspective:
I’ve been a sports fan my entire life, so my interest in trending football news comes as no surprise. As a biomedical engineer, my fascination with the product improvement process is a given. However, what may not be immediately apparent is my deeply personal connection to the efforts in enhancing football safety. As the mother of a 15-year-old boy who not only loves, but actively participates in this sport, I've witnessed firsthand the transformative effects football has had on his character, friendships, physical strength, and discipline. Yet, this enthusiasm is coupled with an awareness of the dangers associated with the sport. The strides made in design challenges and biomaterial improvements aren't just technical enhancements; they hold significant importance for parents, coaches, doctors, and players who are passionate about the sport while prioritizing safety. Kollide's approach of treating the helmet as a medical device is spot on. As the saying goes, "the whole is greater than the sum of the parts." Solving this issue requires contributions from various industries, each providing layers of the solution. It's a collective effort that can make a real difference in ensuring the safety of those who love and engage in the sport.
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