To understand Leatts neck brace testing and what it means to you, youll first need to know what a neck brace is supposed to do, how it accomplishes that, and understand the basics of scientific testing. As much as some of this information may seem obvious, Ive actually read postings and forums where it suggested that, mannequins be launched off of jumps just to see what happens. Well theres a lot more to testing than what can be seen with the eye. And theres actually quite a complex data recording system that pulls all of our information together including high-speed video.
What a neck brace is supposed to do?
As most of you know helmets protect you by absorbing impacts. Chest protectors and elbow guards generally work by spreading the impact over a larger area. And knee braces basically work by keeping your knee from bending ways its not supposed to go. Effective neck braces use similar ideas but not exactly. Leatt neck braces use what we call “alternative load-path technology” to reduce the extreme forces that can occur in any kind or any speed of crash.
Of course, the challenge with motorcycle ATV snowmobile and bicycles is that the riders body is not restrained by any seat belt or shoulder harness, so all Leatt neck braces are designed to work with a full-face helmet to create alternative load paths that are alternative paths. Those paths distribute injury-causing loads to places other than the rider’s neck. When we say loads were talking about the initial head impact forces which normally would travel from the ground to the riders head through the neck and into the body. Alternative load-path technology helps redirect those forces, from the head to the body, in a controlled manner and therefore to less vulnerable body structures.
What often cause injuries:
Note here in the spinal column, how small the top seven vertebrae are in comparison to the larger ones lower down. These top seven vertebrae make up the cervical spine, or neck, while the lower vertebrae are the thoracic and lumbar vertebrae that make up your back. This alternative load path technology is the key to dr. Chris Leatts invention of modern neck braces. Car racing braces technically tether the drivers head to the seat since the driver’s body is completely strapped into the vehicle. In fact it was NASCAR driver Dale Earnhardts tragic death that led to a new and improved design of car racing neck protection. Motorcycle ATV snell beyond bicycle riders because we are not restrained by a seatbelt or harness, face a different set of risks.
Regardless of speed, all of us can crash or lose control and hit our heads in the ground or other hard object and the weight and momentum of the rest of our body can act as a piledriver, pounding us into whatever it is thats stopping our momentum.
This unrestrained torso event is exactly what creates most of the extreme forces that cause neck injuries. The human’s neck can take a lot of punishment before a catastrophic injury occurs and perhaps thats why some riders choose not to wear a neck brace. But in a perfect storm in the combination of the worst possible circumstances, any writer from the fastest most experienced to the slowest and most cautious can experience a career-ending, maybe even life-ending neck injury.
How can a brace protect you?
Now let me be perfectly clear. No safety gear, no helmet, no brace, no chest protector, no piece of safety gear devised by man can prevent all foreseeable injuries. Just as the bones and the soft tissue of our bodies have their limitations, every piece of safety gear ever made has its limitations as well.
Structure of a brace:
Let me now show you how the various parts of one of our neck braces help prevent neck injuries. Bearing in mind that the helmet striking the brace is a key function.
- The front helmet rim strike area.
- The rear helmet rim strike area.
- Lateral helmet rim strike areas for when your head is knocked from one side to the other and puts pressure there.
- A back flip up.
- Front pectoral load dispersion area.
- Collarbone relief area.
- Padding encapsulate s the chassis. Padding also helps bring the head to a stop, thereby increasing the effectiveness of alternative load-path technology, and helps control and reduce rapid brain deceleration which can cause brain injuries. Padding also actively helps prevent the rim of the helmet projecting over the edge of the brace; which if happens causes increased forces on the neck. Padding also helps cushion the chin and helps protect the soft tissues around the neck.
- Engineered fracture points in the sternum area
- Trapezoid winged
- Rear platform and thoracic strut
- Shoulder muscle load dispersion area
- Adjustable helmet strike platform heights to adjust for different neck lengths and body shapes
The above resulting in 360 degrees of protection.
Also theres a rigid chassis for the most effective use of alternative load pad technology, yet yields have predetermined load forces, so as not to produce further injuries. As an example a brace made of solid steel would be the most effective brace possible but would be unwearable and dangerous to other body parts. EMT removal system thoracic strut or scapular wings have managed stiffness angles for fitment a breakaway feature and Perry spinal muscle load dispersion area.
Neck brace testing
Most neck brace testing is not designed to simulate every possible crash event but instead, to produce neck forces that are substantial. Simply put there are thousands of ways to crash, so its just not feasible to test every scenario. Instead, testing focuses on reliably reproducing the primary direction and magnitude of forces exerted on the neck during a crash.
One of the most important aspects of testing is that it be repeatable. Repeatability is the scientific standard that laboratory engineers use. Repeating the same directions in the magnitude of force with a different brace design allows us to study their effectiveness. Some scientific testing also may not look like you might imagine. Youve seen video of cars being crash tested with dummies as occupants, the airbags deploying, seatbelts restraining the dummies on impact. These tests are designed for a variety of purposes and carmakers have conducted these tests for decades. But if you had to look at just the forces applied to the neck, you dont need to destroy a whole car. Engineers use test sleds or bucks to deliver the impact of a crash. This sled being propelled backward, simulating a frontal impact is one example. Testing by organizations such as the SFI foundation use recognized sled test protocols for restraint torsos to measure forces at the neck helmet. Testing can focus on just the head-the only part of the body its designed to protect. Helmet tests include among others using a drop power to drop a weighted helmet onto hemispherical shaped steel anvils. Or to measure resistance to penetration, heavy steel spikes are dropped onto helmets. These tests again may not look much like a crash that you would expect to have, yet theyre an important part of helmet testing that was probably used to certify the helmet you currently own.
Other tests are a little more self-evident as to why they are done. Some of these are tests that make you feel a little more confident about buying the product knowing that it passed, but still do not look like a motorcycle or bicycle crash. This video shows one of our carbon-fiber braces being structurally tested by pulling it with 1200 Newtons of force. This is done to ensure that the connections and hinges are designed well enough to keep the brace together during a crash. The origin of Leatt’s neck brace testing goes way back to the very beginning of Leatt before the full worldwide launch. Dr. Chris Leatt before he had his own laboratory went to BMW in Munich and obtained their help in testing prototype braces.
German engineers in BMWs testing lab conducted in the first pendulum testing as a way to reliably replicate the direction and magnitude of forces that can injure a riders neck in a crash. As you know Leatt makes neck braces for a variety of sports, so we focus on tests that reproduce the forces that can be experienced on a riders neck. Regardless of whether the rider is on a motorcycle, ATV snowmobile or bicycle, since the first pendulum tests performed by BMW engineers Leatt has continually refined and perfected this testing protocol, as well as creating new ones.
Here are most of the types of neck brace testing that we do
- Pendulum testing using our hybrid 3 test dummy
- Motorcycle anthropomorphic test device neck.
Please note that in all the following tests using the hybrid 3 dummy, the majority of the results are not recorded visually. Its recorded through the 24 sensors built into the dummy and captured in a computer specifically designed for the purpose. Please also note that in a real world crash the ground is fixed and the riders body gives way. In these tests, where the dummys body is fixed we have the block simulating the ground give way.
Types of block impacts:
Square block impacts
Standard hyperextension: here the impact block is set lower
in order to hit higher up on the head. This forces the head into acute angle of hyperextension or rear words bending and simulates the upper part of the head hitting either ground or another object and being forced violently backwards.
Posterior hyper translation. Here the impact block is set higher in order to simulate a more full-on frontal impact of the face forcing the head to translate backwards as well as bend backwards. This is an extreme type of injury mechanism.
Standard hyperextension posterior hyper translation and posterior lateral hyperextension: this simulates the head hitting the ground or an object at an oblique angle, forcing the head to bend rear words and sideways at the same time. Such an impact may cause rotational injuries amongst others.
Hyperflexion. Some studies show that this is the most common injury type; about 40 percent of neck injuries happen this way is usually combined with compression. Hence the reason we measure the NIJ (Neck Injury Criteria) which looks at the combination of the two.
Anterior lateral hyperflexion: this simulates the head striking the ground or an object at an oblique angle forcing the head to bend forwards and sideways. Such an impact may cause rotational injuries amongst others.
Rounded block impact:
Secondary hyperflexion and alternative load path theory test: this our most important test simulating flexion of the neck combined with compression. Again, this is the most common injury type and measuring how well the brace reduces those forces and redirects them away from the neck and onto adjacent body structures such as the pectoral muscles and the trapezius muscles. This test shows us how important it is to have protection at the front and not allow 100% of the free forward rotation of the neck. The results speak for themselves.
Pure axial loading: many of the tests mentioned before evaluate the first few milliseconds of a pure compression loading. In a crash, we can clearly show that no neck brace can reduce pure compression acting alone. As this brace is likely not yet in cod act with the helmet at this stage. This type of loading is a rare occurrence but may cause injuries such as burst fractures within the first few moments after the crash before the neck brace can intervene.
The benefit of the Leatt brace is to stabilize the spine after such a crash, help protect the vulnerable spinal cord and help reduce the possibility of subsequent neurological injuries such as paraplegic or even death. Note in this graph that the first portion of the impact is almost identical between tests with or without the brace. This is the pure axial loading phase but you can see the reduction of forces later on in the impact as the helmet contacts the brace and the brace is stabilizing the cervical spine.
Rear breakaway strut testing on both ours and our competitors braces. Techs can pressure testing of the front of the brace visually shows where the pressure points are created on the pectoral muscles of the chest. And the same testing procedure on the back shows that the pressure points are distributed to the top shoulder muscles and the paraspinal muscles not directly on the spine
Sled testing for range of motion was initially done at the South African Bureau of Standards before we started measuring forces strictly at the neck.
- CE structural integrity strength testing
- Environmental testing in heat cold and high ultraviolet light conditions
- Fatigue testing repeated opening and closing of the mechanisms
- Rigidity testing helps demonstrate that a rigid structure works better than a foam soft or flexible structure
In addition to all these tests Leatt has years of experience going back to the very first neck brace using sophisticated computer models of the human neck and back. With these computer models painstakingly refined by our biomechanical engineers, Leatt can study a wider variety of vents than can be physically tested. Computer modeling is done using life mods software and allows our engineers to replicate forces on the neck and body that cannot be replicated with the dummy. Detailed spine models are created using MSC atoms and life mod finite element analysis using MSC sim office and nastran.
What does this mean to you?
So what does this mean to you the writer? Well-documented tests such as NIJ an abbreviated injury score our systems of determining the forces necessary to injure peoples necks. Unfortunately no precise studies have been done specifically pertaining to the types of injuries that our motorcycle, bicycle ATV and snowmobile riders are exposed to. Considering the wide range of potential crash scenarios and individual variations in body size shape and weight, the main criteria to determine a neck brace is value is measuring the reduction of forces. It can increase the force is required to injure you by such a significant amount that it can help prevent many injuries and reduce the severity of others.
Our goal is to reduce the occurrence of any neck injury and reduce the severity of any neck injuries that do happen.