Author Biography:

Daniel Cousins, MSc.

My main area of interest is injuries and human movement, but I can’t be a sword scientist if I don’t write about the science of a sword. For this, I turned to Dr. Jeremy McGibbon, the scientist behind The Standard by Esker Forge. Jeremy is a physicist with extensive training in machine learning and artificial intelligence, in addition to being the maker of one of the most carefully designed swords in HEMA. When I asked about getting into sword making, he explained that his wife was looking at buying a sword and had issues with many of the ones currently on the market, so he decided, why not make one myself. We went through some of the main deicisons behind making the sword. The areas we went over were: mass, stiffness, and balance. When then finished off with a sword makers guide to buying a sword.

Talking about mass was more interesting than I had expected. Changing the mass was where Jeremy put in a lot of thought and effort. A lighter blade is typically easier and faster to move around but will sacrifice strength in the bind. A heavier blade will typically be stronger in the bind, present a better guard and get through a guard better. Esker Forge challenged this using geometry, and after talking to people who use their sword, I would say that they succeeded in a strong and light blade. Obviously, making a strong and light blade would be a massive advantage to the fencer but Jeremy felt strongly about the benefit to safety this would bring. A heavy blade will hit hard, and as I talked about in my post on helmets, the helmets we wear are not good. Being hit in the head by a 1.5kg bar of metal is dangerous and, as proved by their blade, unnecessary. Their blade is 1360g, and I am confident that he could have gone lighter. He is testing an ultra-light alternative to a feder that is currently at 600g, which I am excited to see develop. The mass of the blade is the first thing to look at when you are buying a sword

When it comes to flexibility and stiffness, I learned that these to aspects are quite different but related. Flex is the ability of a blade to deform under stress, and stiffness is the ability of a blade to maintain its orientation under movement. If a blade does not have much flex, it will not bend when thrust and may hurt your opponent. A blade with high stiffness will not wobble/ flop when it is being swung. It is typically thought that a stiff blade will not flex, but that is a matter of geometry and physics. There are two dimensions of a sword that influence the stiffness, the thickness and the width. The thickness and stiffness have a cubic relationship (k=t^3). For example, my HF armory sword is ~5mm thick and would have a k value of 125; the Esker is 6.35mm, which would have a k value of 256, making it twice as stiff. The width is a linear relationship (k=w). This means that to increase the stiffness of a blade, it is more efficient to make the blade thicker than wider. The flex of the blade is based on the taper from the base to the tip. A blade designed with a thick base and an aggressive taper will make the blade stiff during movement but flexible when thrust. The HF Armory sword has a flex rating of 16-17 Kg while the Esker is <15Kg. This gives the next value you should be looking for when purchasing a sword, the maximum blade thickness. Unfortunately, maximum thickness is not a value that manufacturers will often report and that is partly because we as consumers are not asking about it. If a blade is heavy with a small thickness, it will be hard to wield and not have many people who want to spar.

The final aspect of a sword is the tip point of percussion or the balance of the blade. If you were to hold the handle of your sword with a couple of fingers close to the cross guard and move side to side, the blade will swing. Jeremy explained to me that the historical description of the point of percussion is just past the cross guard. This can lead to interpretations of it being on either side of the cross guard but the ideal location, through testing, is 3.5 cm down from the cross guard toward the pommel. The movement of the swing will be in one of three ways: like a pendulum (the tip will move in the same direction as the handle), like a see-saw (the tip will move in the opposite direction) or no movement (the tip will remain stationary). Based on the swing pattern, you would increase or decrease the weight of the pommel until the tip stays stationary. This is important because when you move your hands in different guard positions, you want the blade to pivot around your top hand in order for the blade to pivot properly to keep your tip aligned, your top hand needs to be on the tip point of percussion. If it is not, you will need to constantly adjust the tip position.

When you are buying a sword, you should be looking for these measures and if they are not listed, ask the manufacturer. The more we ask for specific aspects of the sword, they will start to advertise these; if the consumer does not clarify their needs, the producer does not know what to provide. In the meantime I am going to start making a list of different swords and their measurements. Once you have an idea which sword(s) you want, see if anyone at your club has one you can try out or ask around to get other user experience.

I want to reiterate the point about safety, hitting someone and being hit in the head with these swords is dangerous. Both of us agree that HEMA in its current state is not safe and from everything we know about head impacts in other sports, there is going to be some serious long-term damage from taking part in HEMA. Jeremy is exploring different ways to make the swords safer while still staying true to historical texts and I am going to get back to evaluating impacts to the head.

Daniel Cousins, MSc.

On the HEMA subreddit, a common thing I see is people asking about how to get stronger for HEMA or if HEMA is a good form of exercise. The comment section is filled with internet experts who describe what works for them and insist it will work for you. In some ways, I can be considered another one of those internet experts, but I try my best to be informed in my decisions and look for guidance where I am ignorant. That guidance for this topic comes from a close friend of mine, Will Lockwood. Will and I did our undergrad degrees in Kinesiology together, and both were involved in sport medicine for the varsity teams. I spent my time with the rowing team, and he was with rugby. Will went on to become a personal trainer, get his Masters of Professional Kinesiology, become a registered Kinesiologist and is now finishing up his physiotherapy degree in the United Kingdom. Before we get too far into the information, it is important to point out that all aspects of health and physical activity are individualized; what works for one person may not work for another, and if you have a medical condition, you should consult your healthcare professional.

I recognize that everyone has different levels of understanding when it comes to exercise and the human body, so I want to start off with a couple of key concepts. The first concept is mobility, it is the total range of motion of a specific part of the body. Each joint has its own range of motion and then all of the joints can be combined to increase the range of motion of the limb. If you think of the arm as 3 pieces of a chain that are linked together, each link can move a certain amount, so the total movement of the chain is all of the links combined. The next concept is stability, which is your ability to move through a range and keep the structure of a joint. If you think of waving a wet noodle around, there is no stability to it. These first two concepts work together and in some ways, oppose each other. We want to be able to move through a large range of motion and keep the structure.

The third is the kinematic chain; it is the idea that all of our joints are connected, and what occurs at one joint will impact a joint further in both directions of the chain. All of our movements are coordinated actions between joints for example, the shoulder, elbow, wrist, and hand will all work together to make a smooth motion. I have had multiple shoulder surgeries and have a reduced range of motion; this means if I want to reach a specific item, I will need to rely more on the rest of the joints to reach my end target. Alternatively, if I had an injured wrist and had less range, I would need to use the earlier joint to adjust to that. The kinematic chain is not limited to a single limb or even a single side of the body but the entire body is linked together.

Now that’s out of the way, let’s dive in. Before talking to Will, I sent him some videos of basic movements and positions for both sabre/ broadsword and longsword to get an idea of the movements and physical demands of HEMA. I also told him of some areas where I feel pain, discomfort and weakness to get some targeted exercises and stretches, which hopefully you can benefit from. While I focus on a couple of movements in the two disciplines, it does not mean that they are only applicable to those disciplines. It makes it easier to get someone to adopt a new practice when the specific benefits can be identified and the exercises have easy to see direct benefits to the different sword types.

We started off with longsword and the main area that I wanted to talk about with him was shoulder mobility, especially when overhead. I personally have had three right shoulder surgeries and was expecting to get the advice I got from my previous physiotherapists and was surprised when he started talking about the spine. For context, the spine is broken into 3 regions, the cervical, thoracic and lumbar. The lumbar region is responsible for flexion and extension of your torso and the cervical is responsible for your head but the thoracic is a jack of all trades where a lot of mobility issues come from. Your shoulder is made up of a lot of complicated structures and the common ones people think about for the movement is the ball (humerus) and the socket (glenoid). The glenoid is the area on your scapula (shoulder blade) that your humerus connects but the scapula still needs to attach to the rest of your body. In the front, the connection is to the clavicle (collar bone) and the back, it is to the thoracic spine. The movement between the vertebrae in the thoracic spine, and between the scapula and the spine can result in a lot of stiffness and limit getting your arms into a high position. Some good movements that he recommended for cat-cow poses with some rotation to build the movement in the spine. Then thread the needle to get the scapula moving. The important part with this stretch is to make sure you can feel some movement in your scapula and not just rotating your spine and stretching out your arm.

Once you have that range unlocked, you need to make sure you have structure in those extreme positions or your block won’t be effective. There are a lot of different ways to get that structure but one that he suggested was using variations in plank positions. Planks are a great way to create stability across the entire body and you can vary your hand positions quite easily. If you take the standard plank position and slide your hands further above your head you can start building up strength in those higher positions. You can also move them further out to either side. There are ways to turn this into a partner drill by having two people form a “T” shape where one partner’s head is roughly and the other person’s ribs. The partner with their head at the other’s ribs will lift one arm out of their plank and push against the other person. Both people should stay in their positions.

We then moved to sabre/ broadsword, which also moved us to the lower body. You will not often get in the same awkward position that requires a lot of shoulder mobility and stability but the lower body becomes more important. I brought up two main things with Will: comfort in the stance and lunging. The stance is going to be fairly individualized, while there is an “ideal” way to stand, each person will need to make adjustments based on their own body. There is one useful exercise he mentioned to make the stance feel more comfortable. Internal and external rotation of the hips will allow for you stand with a small profile while presenting a threatening posture. A common exercise for this is called 90-90s or windshield wiper. It can be done in either a seated position or laying on your back. The outside part of one leg and the inside of the other will touch the ground with your knees bent to 90 and switch from one side to the other. When it comes to lunges, you need mobility in your ankle, knee and hip. An easy way to do this is deep lunges while rocking forward and back. For this lunge, you want your back knee on the ground and front leg at 90. You then lean as far as comfortable forward while keeping your front heel on the ground and then lean as far back as possible while keeping your toes down. This should be done slowly and with control.

This is probably going to be my longest entry and before I end it, I want to give some final thoughts. First is strength, being strong in HEMA is not a large advantage but the ability to produce and accept controlled amounts of force is very important. Being stronger can make this easier but good technique is much better. The next is taking care of your body. HEMA is a contact sport that requires high intensity exertions. You need to recognize when you have pain, and if that pain is new or getting worse. You need to be aware of your body; it will tell you what it needs. A big thing people tend to have a hard time is that avoidance is not a good way to heal. Avoiding treatment and avoiding the movement could make things worse.

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.