In boxing, behind every punch connecting and glove pushing into a face, there is a complex collection of engineering principles at play that can vibrate a human skull and cause serious neurological damage. The impact of a punch can jolt the brain, causing it to move across the cerebrospinal fluid that it sits in and putting the person at risk. The rotation and rebound of the brain inside the skull from the rapid force applied is what produces concussions in the sport. Theoretically, headgear will reduce the likelihood of a concussion by softening the blows.
Today, we will go over if this translates to a real reduction in brain injuries for boxers. In an investigation by Sanzo, Rybak, and DiMarco, they found that modern boxing headgear is effective in reducing linear accelerations of punches to the head. The results of their 2023 study showed that headguards proved to be far less effective at reducing rotational acceleration, which is correlated the most with concussions. So boxers wearing headgear were significantly less likely to be bruised or cut, but not nearly as protected from brain injuries (Sanzo et al., 2023). It was found in some tests that certain models of headgear increased the rotational motion a small amount. This slight increase is due to the bulk added to the head region by the padding in the headgear, which proves to be effective for absorbing direct impacts; however, for punches thrown at an angle of rotation, the additional radius increases the torque.
Studies from 2018 performed by Razaghi, Ghaffari, and Hasanzadeh reinforce these same findings. This mechanical study tested 12 commercially available headguards and concluded to test how foam layering and stiffness play role in energy absorption (Razaghi et al., 2018). It was found that softer foams were effective for low-energy absorption; however, they were easily flattened in high-energy impacts at high speeds. These high-energy collisions transfer energy directly to the skull. For harder foam headguards it was found that they were noticeably less comfortable and had secondary acceleration peaks. These tests concluded that there is not a single headguard material that prevents concussions, but there are ideal foam densities to prevent such damage.
Research from 2021 analyzed amateur and Olympic boxing data to search for positive or negative correlations between headgear and concussion prevention. Viewing data over 50 years (Tjønndal et al., 2021) found that boxing headgear effectively decreases external injuries, but it was inconclusive if it decreases rotational trauma that caueses concussions. The lack of evidence for decreasing rotational trauma is one of the primary reasons many international boxing organizations do not use headgear. In the AIBA boxing organization, they believe the lack of neurological protection that headguards is reason enough to remove them from competition despite their proven effectiveness in protecting boxers from external injuries, such as bone fractures or cuts.
In a 2017 biomechanical study exploring this paradox, advanced cameras used to capture high-speed motion and boxing dummies were used to replicate boxing hits (Le Flao et al., 2017). The tests were conducted from a variety of different angles, punch locations, and head movements so collect data with a range of impact transmissions. The findings indicate that body and neck posture can be as or more important than headgear for acceleration loads. This is where the sayings roll with the punches and tuck your chin come from. If a fighter rotates their body or uses their shoulder to take the impact of the punch they are able to effectively protect themselves from neurological damage. The movement effects how energy is absorbed in the head and neck area, which is a biomechanical finding any experienced boxer learns to master.
The ability of headgear to protect against external cuts and bruises is very real and backed by clear evidence. However, the assumption that the same is true for neurological protection is unfortunately false. The closest finding is that headgear in some cases reduced direct-force acceleration, which could be preventively effective for reducing long-term issues such as memory loss and cognitive failure. For any athlete, it is important to understand that every impact to the head, including non-concussive blows, can lead to unwanted neurological effects, and protecting the brain goes beyond the equipment we use.
Research is being conducted in search of a solution to this problem for boxers and protect the next generation of fighters. New materials composed of layered viscoelastic foams and gels are under development with the primary goal of absorbing linear force and reducing rotational acceleration. Along with this material research, headguards with built in sensors are being used to capture real time impact data (Di Marco et al., 2023). The quest to better understand and track biomechanical forces will change the lives of athletes and fighters who are concerned about protecting their most valuable organ: the brain.