The Brain Bucket

According to History of Armor, helmets have been in use for thousands of years. 

Initially designed to protect you if you were smacked in the head with a club or a rock, modern mountain bike helmets are used to reduce injury if you smack your noggin against trees and rocks. So, other than moving from bronze and copper to plastics and high-density foams, maybe not much has changed in a few millennia.

Although now, instead of asking a blacksmith to pound out a head-shaped piece of metal, you can go to a bike shop, sporting goods store, or online and choose from hundreds of different options. What’s the difference between a $30 helmet and a $300 helmet? Plenty, but before getting into the differences in fit, venting, weight, looks, and durability, let’s cover what helmets are actually protecting you from.

Concussions and More

NOT a great CT to have.

I've mentioned that I'm an emergency medicine provider with nearly 20 years of experience, so I’m no stranger to dealing with head injuries. I see them from falls from horses, falls from ladders, car accidents, bicycle crashes and even just falls from a standing height. 

Many factors can increase the risk of sustaining a serious head injury, or “traumatic brain injury” (TBI), and those include the height from which a person fell, the speed they have been traveling, the age of the person, and certain medications (primarily ones that “thin the blood”).

Head injuries can be broken down to mild, moderate and severe by two sometimes conflicting criteria–structural damage to the brain and/or neurologic symptoms. I say these are at times conflicting because a person can have concerning neurologic symptoms, but no visible damage to the brain (seen on an MRI or CT scan), and/or a person could have bleeding on the brain or a skull fracture, but little to no neurologic symptoms. 

Many people are familiar with concussions as they are fairly common. Concussions symptoms can range from short lived dizziness or nausea, to longer term difficulty concentrating and headaches. There is no specific treatment for concussions, and no specific test that can confirm or exclude a concussion. Any tests, like MRIs or CT scans are done only to look for other injuries such as bleeding. 

With enough force, blood vessels in the brain and the brain tissue itself can get damaged, leading to bleeding. In some cases, a small amount of bleeding won’t cause long term problems, but more significant bleeding can lead to disability or even death. 

Bottom line, while most head injuries will be minor, even mild hits can cause a concussion, which can have long term effects. And, that’s not even talking about the issue of multiple concussions over a lifetime which can lead to a condition known as Chronic Traumatic Encphalopathy (CTE). CTE has gotten plenty of publicity because of its effects on football players, but it can happen to anyone with a history of several head injuries. How many? No one knows. So it’s a good idea to do what you can to reduce your risk.

I think we can all agree that head injuries are bad, but do helmets really work to prevent them?

Test and Certification

All helmets sold in the United States need to be certified by the Consumer Product Safety Commission (CPSC). The helmets are tested to ensure that they are able to withstand certain impacts such as being dropped from about six feet against a flat anvil or four feet against a curb-shaped anvil. The helmets need to prove that they reduce peak acceleration to less than “300g.” What?

In this case, a “g” is gravity and is used to determine the amount of force that would be exerted against the head and brain in an impact. Walking around, here on Earth at least, we’re experiencing 1g just about all the time (except when taking off in a plane or dropping on a roller coaster). More g’s equals more force. If you want to see the technical calculations, head to your favorite physics reference web site or over to helmets.org, which does a great job explaining the science. Calculations show that about 1000g’s can be transmitted to your brain in two-thousandths of a second in a fall without a helmet. Helmets slow that impact down to seven or eight thousandths of a second to disperse the “energy pulse.” 

The CPSC certification is needed to be sold in the US, but there are other certifications that helmets can meet including Snell, and American Society for Testing and Materials (ASTM) that are more rigorous but are totally voluntary.

With all the different certifications it can be confusing, but fortunately other organizations such as Virginia Tech and Consumer Reports conduct large-scale independent testing to help guide riders when choosing a helmet. 

Helmet manufacturers use various methods and materials to meet these certifications,  while also making the helmets lightweight, cool, and comfortable. Additional innovations have come along beyond the standard Expanded Polystyrene (EPS) foam to add more protection. 

Got MIPS?

For the most part, helmets were designed to protect against direct impacts, which is why standard testing involves them to be strapped to a “headform” and dropped vertically onto an anvil. The reality is that most crashes are not direct impacts and can include rotational forces which also injure the brain. 

In the mid-1990’s, a Swedish neurosurgeon, Hans von Holst, along with researchers Peter Halldin and Svein Kleiven started looking at those rotational forces and considered ways to mitigate them. Multi-directional Impact Protection System, or Mips, was born out of this research and helmets with the Mips technology feature an inner layer that allows for a small amount of helmet movement; enough to help disperse the impact from a crash and help protect the brain. 

The attention to rotational forces that Mips put on helmet designers also prompted other innovations, and while many people look for the recognizable yellow Mips logo, Trek/Bontrager’s WaveCel technology is also effective, and maybe even more so. O’Neal uses IPX ACells. No matter which option you go with, they all seem to help reduce the risk of brain injury.  

The big question is, however, do helmets really work? Intuitively, you’d have to agree that anything that can reduce the forces transmitted to the head, and brain, from an impact would be beneficial. So, if helmets can prove that they do reduce those forces, it should be inferred that they reduce injuries. Many studies have supported this. A truly pedantic researcher *could* point out that the only real evidence would be to have a randomized controlled trial where people of similar age and health were hit on the head with similar forces, some with helmets, and some without, to actually say that helmets work. A similar argument has occurred regarding the use of parachutes, as no one has really ever done a well designed study on their effectiveness. But, I digress.

Buckle-up and Send It

I’ve bored you with some science but hopefully you have a better understanding of what helmets do. So, now, how do you pick between a $20 mountain bike helmet on Amazon versus a $224 Fox Dropframe Pro? At the most basic level, both meet CPSC requirements, so both meet the minimum protection requirements. The similarities end there, as you’ll tend to find better ventilation, better fit and retention straps, removable and washable padding, lighter materials, and safety ratings that probably well exceed CPSC’s standards.

You might also wonder about the differences between road helmets and mountain bike helmets. Again, both will meet CPSC requirements, and many road helmets will have all the same advantageous features (Mips, good vents, etc), but road helmets will tend to be more focused on aerodynamics while mountain bike helmets might be slightly heavier because of added coverage areas. Mountain bike helmets are also now being designed to better accommodate goggles and GoPro attachments, because if you’re gonna send it, you’ve gotta film it.

While it’s good to compare all the different features, including safety ratings, it often comes down to fit and style. I did an informal survey amongst many of my riding buddies and common brands were Giro, POC, 661, Troy Lee Designs, Louis Garneau, and O’Neal.

My go-to helmet right now is O’Neal’s Pike IPX. It fits my head well, is relatively light at just under 400g, has IPX ACells to provide rotational protection and has overall good coverage. And, at $149, is a good mid-range helmet. 

Dave’s Story

I advocate for helmet use in my current job as an emergency medicine provider, but in a previous life I was a professional BMX rider, and my good friend and teammate, Dave Tufts, and I would travel the country doing stunt shows that also highlighted the importance of bike helmets. He’s knocked his bean a few times, here are his thoughts on helmets:

“I’ve ridden bikes my whole life. I love riding and it’s really something that is good for me mentally and physically, but if you’re going to ride, inevitably you are going to crash. I mostly ride BMX flatland and mountain bikes, but also my road bikes off and on.  I’ve actually had quite a few small concussions from a car accident, an accident at work and of course bike crashes. (editor’s note: also, another time he tried to do a backflip off a small concrete platform and essentially jumped up, got upside down, and landed head first… the editor is embarrassed to note that at the time this was quite funny)

About 7 years ago, I rediscovered my love of mountain bikes and went from my very old outdated bike  to a very high end full carbon Cannondale. It was literally my dream bike.  I was so excited to get it that I also bought a new helmet.  I found Bell’s light weight full face Star Wars helmet with removable jaw guard that was painted green to look like Boba Fett. The Force took over so I ordered it. Yes I’m a dork. 

Anyway, the reason I went with the uncommon full face helmet for single track trail riding was because I know ME out in the woods. I like to ride somewhat on the edge–it’s fun. And, I’m very aware of all the obstacles like trees, rocks, etc that can affect me in a crash.

 

 Twenty years ago I was riding my BMX bike on a halfpipe ramp and I had a major crash from 8 feet up. I hung up the back wheel and went face first into the plywood at the bottom of the ramp. I never took my hands off the grips. I tore my AC joint in my right shoulder and got one heck of a concussion. Luckily that day I was wearing a full face dirt bike helmet and it saved my head and my face from much worse. I got knocked out cold and woke up in the bushes off the side of the ramp.  I had 2 surgeries to fix my shoulder, but luckily had just a moderate concussion at the time. Having experiences like this helped me realize that the forces involved when falling while flying down a trail aren’t that much different from riding ramps and crashing.

 

About 6 months into ripping with my Cannondale I had another accident and concussion. I wasn’t myself for about 2 weeks. And again, luckily I had that Boba Fett full face on. I was going Mach-10 into a turn and my front wheel hit some slick clay and instantly washed out to the side causing me to straight up pummel my forehead and face into the ground. It was lights out again. I woke up about 6 feet from my bike face down. I was in the ferns out cold and there was dirt on the backs of my gloves from them dragging next to me. My world was spinning and my forehead was bruised, but my jaw, nose and face were ok. I had a headache and my friends all definitely noticed a difference in me for a while. But without that helmet it would have been MUCH worse!  I bought another one and I don’t ride without it. I think my helmets are cool and they work. I’m proof because I can still ride.”

Protect Your Head, Protect Your Helmet

Helmets, like the rest of your riding gear, will have a limited life span, and even without a crash, helmets should probably be replaced every few years. Over time, high heat (from keeping your helmet in a hot car), UV exposure and general wear and tear could decrease a helmet’s effectiveness, but you may want to replace your helmet when new colors or styles hit the market.

If you do have a crash–even if the helmet looks okay–it should be replaced. Helmets are designed to only protect you from one crash. Some helmet manufacturers offer crash replacement discounts to help ease the pain. 

This means you may need to spend a bit of money upfront for a good helmet and may need to replace it, whether after a crash or just over time. Many years ago, Bell helmets had a great ad campaign that asked, “does your kid have $100 feet and a $10 head?” showing that many parents will spend more on sneakers than a good helmet. The point though was that in many cases you get what you pay for. Cheaper helmets may still meet the CPSC requirements, but they are not going to offer the same protection and features as more expensive models. You don’t necessarily need to spend several hundred dollars (although, many of the top rated helmets on the Virginia Tech testing are in that range), to get light weight, good ventilation, and excellent protection.

According to TBI.com, “Cycling, in its various forms, causes the most head injuries of any recreational or sporting activity,” so chances are that at some point in time, you may go down. Thousands of years ago, people knew how important it was to protect their heads, so it should be a “no brainer.” (#dadjoke)

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