Author Biography:

By Daniel Cousins, MSc

Like every other contact sport, there is a concern about concussions and a desire to reduce their incidence. While the self-governance of clubs and tournaments is crucial to allow for individual interpretation of historical texts, thereby keeping HEMA as accurate as possible and preventing sportification, it has some flaws, and injury prevention is one of them. This means there is no easy way to track the injury status of a participant within and between tournaments, nor is there a method in place for someone else to rule out a participant; it is a self-declaration. HEMA tournaments could, in theory, add concussion spotters, but it would be difficult to implement. First, there would need to be an additional judge/ spotter for each ring to watch the matches, when tournaments can struggle to get enough people already. Next, spotters would typically watch for specific hits to the head that look dangerous, but all hits to the head in HEMA could look dangerous. You are hitting someone in the head with a large piece of steel. This would mean the spotter would need to watch for changes in movement patterns and behaviour, which would require a significant amount of training, further limiting the number of qualified, volunteer spotters. Another solution that other sports have implemented is banning specific types of hits. In HEMA, the head is a valid and high-value target; removing all hits to the head would be a large detriment to the sport.

If the rules cannot change, then the equipment needs to. The first thing that we should discuss is what a concussion actually is and how they are caused. A concussion is also commonly called a mild traumatic brain injury (mTBI). It happens when the brain and the skull collide through direct impacts and/or rapid acceleration/deceleration. That is as detailed as I intend to get on concussions and will now switch over to how we stop them using equipment and for that I turned to a friend.

I sat down with Tom Hoshizaki to talk about head impacts, helmets and a way to make HEMA safer. Tom is a PhD student who studies ways of reducing impact characteristics on the head from techniques on falling to helmet design. Tom has been around concussion and head impact research for a long time, and in some ways, it’s the family business thanks to his father, Dr. Blaine Hoshizaki, the director of the Neurotrauma Impact Science Laboratory at the University of Ottawa. The first thing we talked about was the helmet rating system using the CEN 1 and 2 criteria for puncture. HEMA and Olympic fencing are tied together in a lot of ways, and puncture is a pretty big concern whenever swords are involved, but we should differ when it comes to the head. The blades used in Olympic fencing are much lighter and more flexible than those in HEMA, so high-impact forces are not a major concern. The CEN and FIE ratings on helmets concern the puncture resistance of the bib, the puncture resistance and material of the mask and the general shape of the sides and back. This is unrelated to the ability of a helmet to absorb forces. For the helmet rating systems, a more appropriate sport to look at would be lacrosse, where a stick can, and does, make contact with the sides and top of the head. Lacrosse helmets are certified through NOCSAE (National Operating Committee on Standards of Athletic Equipment) and use a metric called the Gadd Severity Index (GSI) or the Head Injury Criterion (HIC). These measurements take the rotational and/or linear accelerations of the head and the duration of the impact to predict the risk of injury. NOCSAE has a limit of 5000rad/s^2 for rotational force or 156g for a linear acceleration. For a helmet to be acceptable, it needs to be able to absorb enough force from a realistic impact in the sport to reduce the acceleration on the head to be below these values. This brings us to the first issue. What is a normal head impact in HEMA?

There is currently no data on the head impact characteristics that occur in HEMA. In order to know how much padding a helmet needs in order to reach a target, you need to know what it is going to be facing. I have a project planned to begin to build up some normative data on different impact sites and angles from different swords. This will then give an idea of what parts of the helmet will be facing what kinds of forces. From there, we need to impact test the helmets. The helmets and overlays have next to no padding on the inside of them, and what padding is there is mainly for a better fit to the head. In all likelihood, they will not pass the ability to reduce force. The good thing that he said going for us right now are hard plastic overlays. These overlays and helmet styles (Rattlesnake) will have a lower friction on them, and a cut will have a better chance of glancing, so less resultant force goes to the head and for a shorter duration. From here, we need better designs on helmets and overlays. For force to be reduced, it needs to go somewhere, and the best way to do that is through a material that will deform under the force. An interesting engineering problem is going to be what to do with he masks. Very few sports tolerate any kind of direct impact to the face, and someone smarter than me will have to come up with a way for the mask to reduce resultant acceleration on the head.