I wrote this piece for Living Safer Magazine. If you ride, read it.
Bicycle helmets have been ubiquitous in the cycling community for decades. Laws requiring children under certain ages to wear bicycle helmets exist in every state, and for good reason.
Statistics show that bicycle helmets reduce the likelihood of serious head injuries in a bicycle crash by 60% overall, reduce the likelihood of a traumatic brain injury by 53%, and reduce the risk of fatality by 34%. Those are significant reductions for simply wearing what is essentially a “hard hat.” So, how do they protect your head?
Linear/Direct Impact Injury
Bicycle helmets provide primary protection against blunt force trauma that could potentially cause a skull fracture through the use of a foam interior and hard outer shell. Such blunt forces are called linear or direct impact forces. It is easy enough to understand what could happen if you fall from a bike and your head strikes a solid object such as a tree, a car or the ground. Helmets provide a crucial barrier between your skull and the outside world, potentially saving your life.
Skull fractures can result in some of the most serious injuries a person can sustain, leading to a litany of lifelong problems and, in many cases, death. Even from a seemingly minor impact, when your skull isn’t fractured, you can still sustain a “closed head injury,” such as a subdural hematoma (bleeding or bruising of the tissue surrounding the brain) or a concussion.
Axonal Shear Injury
An axonal shear injury is caused by the rapid rotation or deceleration of the head. These injuries are typically “closed head” injuries that do not involve skull fracture, but rather cause injury by the brain’s sudden movement within the skull. They can also result in serious long-term injury or death.
A Multi-directional Impact Protection System (MIPS) is a patented technology that protects the head from the rotational forces that can cause or worsen traumatic brain injuries. Today, all serious cyclists wear helmets with MIPS technology. MIPS reduces the transfer of rotational force to the brain by providing an almost floating barrier between the rig that secures the helmet to your head and the helmet’s hard shell.
MIPS doesn’t provide extra protection from a direct blunt force impact to the head. It allows your head to move slightly within the helmet so that if your helmet strikes something, your head has extra room to move without having the helmet transfer 100% of the energy of the impact to your skull, and subsequently your brain. This is particularly effective when the helmet gets suddenly stuck, even for a split second, on whatever it has impacted.
While a non-MIPS helmet will still provide you with some protection from blunt force trauma, helmets without extra protection against rotational forces are completely lacking in protection from axonal shear injuries, which can be devastating. Studies have shown that MIPS technology further reduces the risk of closed-head injury by at least 10%. The reality is probably higher.
WaveCel Technology
While MIPS reduces rotational forces in the event of an impact, WaveCel claims to reduce both rotational and linear forces by distributing the energy of a blunt impact through a network of cells on the interior of the helmet, flexing and gliding in such a way as to divert the rotational forces that a MIPS helmet seeks to minimize.
Other Helmet Safety Technologies
There are other technologies that claim to protect against axonal shear injuries, such as SPIN, Fox Fluid, Turbine Leatt, Kali Protectives, Koroyd by Smith, SHRED and KinetiCore. While these are less common than MIPS or WaveCel, you may come across them during your search for a proper helmet.
Which Helmet is Right for Me?
Choosing the right helmet is critical to maximizing the protection it provides. The most important factor is fit. The helmet should fit you well: not too small, which would unnecessarily expose the sides of your skull, and not too large, which could cause it to slide around if you’re thrown from your bicycle or if the helmet hits something. It should have a firm, snug fit when tightened.
Resources for Researching the Right Helmet for You
There are many online resources available to assist you in your search for the right bicycle helmet. The gold standard for helmet reviews is conducted each year by Virginia Tech, whose Helmet Ratings are widely accepted as the most comprehensive bicycle helmet evaluation and rating system in the world. In 2024, they rated 241 bike helmets of all types. You can explore the ratings here.
Another great resource is the Bicycle Helmet Safety Institute, found at helmets.org. They provide a comprehensive, though somewhat cumbersome, website full of data, analyses and other fantastic information.
The jury is still out on whether WaveCel is truly as effective as MIPS, but if you look at the 2024 Virginia Tech Helmet Ratings, you won’t find a WaveCel helmet in the top 20. They’re all MIPS. At a minimum, if you want to truly protect your cabeza, you need a helmet with some form of extra protection against the rotational forces that cause brain-shearing injuries.
The bottom line is to take your helmet purchase seriously. Do your research and find the right helmet for you. Taking the time to do it right could quite literally save your life.
Originally published in Living Safer Magazine, Volume 16 Edition 3. Read the full issue here