The Ideal Helmet Standard
Summary: Our ideas for an ideal helmet standard.
There have been almost no advances in bicycle helmet standards in the US since the early 1990's. Why have standards not improved in a so many years?
Any standard must be practical. A manufacturer must be able to meet it and still sell helmets. The Snell foundation published a bicycle helmet standard in 1970 requiring a heavy, hot helmet in the motorcycle style. Very few helmets were ever certified to it, they did not sell at all, and it was quickly forgotten. Upgrading standards is tied to upgrading protection in a wearable, marketable helmet, and that has not occurred since the early 1990's.
The second constraint on helmet standards is the ability to design an accurate test that can be replicated across multiple laboratories with uniform results. That limits the parameters that can be tested. How do you design a uniform test for ease of helmet adjustment, for example, when many subjective factors may be involved. And how do you test for "strap creep" that permits straps to loosen in use, when they stay adjusted for the rolloff and strap strength tests.
The third major constraint is a lack of precise medical data on exactly what level of protection is required to prevent either the worst of the brain injuries or the milder concussions that we would all like helmets to prevent. Then there is the still-perplexing rotational injury component of brain injury, and its relationship to helmet design.
With these limits in mind we still think it is useful to consider what an ideal helmet standard would look like.
Requirements for an Ideal Helmet Standard
1. Energy Management: A single lab test rig design in all labs. Lab drop tests at least 2 meters on all anvils. Variable weight headforms that roughly correspond to the actual weight of the head size. All g's below 200, or below some defensible number representing minimal risk of concussion, probably closer to 100.
2. Strap system: Hold in dynamic yank equal to current standards, but pull off after 3 to 5 seconds of steady pull to prevent playground hangings. Test for strap creep in use. Durability test for all parts involving thousands of cycles for the fasteners.
3. Fit test: Rolloff test, plus a displacement test with minimal shift on the head permitted. Test for ability to accommodate most or all head shapes.
4. Comfort tests: Test for minimal ventilation. Weight limit. Limit for restriction of peripheral vision. Perhaps someday a test for sweat control.
5. Exterior shape: Test for smooth and round exterior without elongated shape or any projections that could snag, including helmet shell design features.
6. Mount for breakaway mirror and visor: Test for standard mounts.
7. Visor and accessory test: Test for shatter resistance of any visor or accessory sold, as well as conformity with breakaway specification. Test for minimum visor deflection when snagged.
8. Visibility: Test for day and night conspicuity.
9. Durability in use: Test for shell scuffing and fitpad rot.
10. Cleaning: Test for durability when cleaned with common cleaners.
11. Instructions: Test for clear, concise, understandable instructions for fitting and use, available in the native language of the user, with graphic representations.
12. Coverage: Specification for area of coverage that includes 95 percent or more of documented impact locations.
13. Environments: Current conditioning standards are probably adequate for low temp, high temp and wet testing.
Do we anticipate this ideal standard in any reasonable time frame? No. There have been so few advances in helmet technology over the last decade, and there is so little incentive for manufacturers to plow money into research and development, that we would not anticipate helmets that could meet an ideal standard in our lifetime, and probably not in yours either.
There have also been no major advances in lab testing equipment and protocols over the last decade. Old arguments about test rig designs have never been settled. No private or public lab is investing in research on major new systems for improving our testing. No new advances in designing better tests are on the horizon.
Development of an international bicycle helmet standard is stalled. Europe has a different test rig that it considers superior and the US regards as unnecessarily complex. The US uses two different drop rigs that produce slightly different results and studiously ignores the problem because each rig has its champions who regard the other as inferior, and because nobody wants to invest in new rigs. The US uses 2 meter drop heights, while Europe uses 1.5 meters, resulting in helmets that are thinner and often will not pass US tests. Europe uses a 250 g failure criterion, while the US uses the same 300 g threshold that it has used for 50 years and can't let go of. In fact Consumer Reports
In the absence of better standards, manufacturers are stalled in improving their helmets by two constraints: marketing and legal liability. They are convinced that they can't sell a helmet that is thicker and therefore bulky looking. And their lawyers will not let them advertise that a helmet is "safer" or "more protective" or even "designed to prevent concussion" for fear that they will lose lawsuits when a rider is injured in that helmet.
We are appalled at the pessimism of this conclusion. In the absence of major new initiatives by somebody in the field, there will not be any significant improvements in helmet performanc in the next decade.
There are two rays of hope: a new group began work in 2002 on providing the medical underpinnings for advances in standards based on more accurate injury thresholds. For more info, check on our page on what we need to make progress. And for concussion data and research we are now indebted to football players, who suffer more economic loss from concussion than any other population group and are now funding basic research in this field. Results of that research began to become public in 2004, and may someday result in improvements in helmet design, at least for football helmets. Here is an article in Discover Magazine titled Lights Out: Can contact sports lower your intelligence? that discusses some of the info emerging on concussion levels and mechanisms.
This page was last revised on: August 24, 2007.