Bicycle Helmet Safety Institute

Helmet Construction and Performance

Summary: Resources for researching helmet construction and performance.

• Our page for helmet designers, with many of the same references as this page.
• Our basic page on how helmets work and what standards do.
• Our page on the Ideal Helmet.
• Our page describing Helmet Standards.
• Our page describing Helmet testing.
• Our short Summary of Helmet standards: answering five questions on standards.
• Our long Comparison of Bicycle Helmet Standards, comparing the world's bicycle helmet standards point-by-point.
• Our page on what is needed to make progress in helmet standards.
• Our page on the limits of helmet protection.
• Our page attempting to describe What is a "g".
• Our page of calculations for the severity of lab tests compares the drops to MPH speeds.
• Our page on how helmets are constructed and what materials they are made from.
• Our page on helmet foam.
• An analysis of energy management thickness for an anti-concussion helmet.
• Our page on helmets in cold temperatures.
• Our page on helmet patents.
• Our advice for inventors of new helmets.
• Our page on full-face helmets.
• Our page on helmets that are inmolded.
• A study of the effects of sliding resistance of a helmet in a crash.
• A study of chin strap forces in a crash related to the sliding resistance of a helmet.
• Our ideas on what happens in a crash.
• Our best guesses on the cost of manufacturing a bike helmet.
• Our page on bicycle helmet history.

Some great articles

• Motorcyclist magazine publishes excellent articles on helmets. Well researched and written, we recommend them for general background even though the focus is on motorcycle helmets.
• Lights Out: Can contact sports lower your intelligence? This article appeared in Discover Magazine in December 2004. It was a very interesting source of info being developed on concussion levels and mechanisms.

Helmet Optimization in Europe

The HOPE study is a full-scale Europe-wide examination of helmets and their effectiveness. Nobody has ever done this before. The Final Report (2015) conclusions include:

• "..most bicyclists in Europe recognise the increased safety of wearing a helmet. However, they provide an extensive list of reasons why they still do not do so, including thermal discomfort."
• "The primary conclusion of this Working Group is that the full potential of bicycle helmets has not yet been fully exhausted. In fact, helmets could even provide additional benefits, when protection is extended further on the lateral side."
• "Working Group 1 is confident in its recommendation that increased usage of bicycle helmets can reduce the number and severity of head injuries."
• "While literature varies on the overall effectiveness of bicycle helmets, the inconsistent usage and lack of data mean that absolute conclusions cannot yet be drawn about the overall impact of bicycle helmets on safety."

There is much more in the report, including recommendations for changes in bicycle helmet testing standards.

Statistics and Medical Journal References

• Our page of Statistics from various sources. Of course they don't agree--just take your pick!
• Our page of peer-reviewed journal articles from various medical and injury-prevention journals.
• CR 195: Bicycle helmets and Injury Prevention: A Formal Review (2000) "Bicycle helmet efficacy is quantified using a formal meta-analytic approach based on peer-reviewed studies...The results are based on studies conducted in Australia, the USA, Canada and the United Kingdom, published in the epidemiological and public health literature in the period 1987- 1998. The summary odds ratio estimate for efficacy is 0.40 (95% confidence interval 0.29, 0.55) for head injury, 0.42 (0.26, 0.67) for brain injury, 0.53 (0.39, 0.73) for facial injury and 0.27 (0.10, 0.71) for fatal injury. This indicates a statistically significant protective effect of helmets." BHSI note: Most of the "helmets" in pre-1987 days were not capable of meeting today's standards. If the study were redone with more recent data we would expect a more protective effect would emerge.
• Our list of Mandatory Helmet Laws in the U.S. and elsewhere.
• A long study and detailed 1995 review of the literature on The Effectiveness of Bicycle Helmets by Dr. Michael Henderson. Badly outdated but still good.
• Circumstances and Severity of Bicycle Injuries, a summary report of Harborview's Helmet Studies. You can access the full study on the Snell Memorial Foundation website. Highly recommended!
• The UK has published a study of helmet effectiveness geared toward decision-making on mandatory helmet requirements.
• The Health Department of Western Australia has published a study of bicycle injuries and deaths over the period 1981 to 1995. It shows a drop in the proportion of head injuries as helmets were adopted.
• Our review of an article on helmet fit problems as documented by a pediatric practice in Falmouth, Massachusetts.
• Improved Shock Absorbing Liner for Helmets is a study done by the Australian Department of Infrastructure and Transport testing standard foam liner materials against a "Cone-head" dual density liner."The newly designed shock absorbing foam liner, when compared with the current liner, displayed significantly more crushing, greater timeduration (interaction), less slab-cracking and recorded peak decelerations less than the required 300 g's (g-force)."

Consumer information

• Our workshop titled Frequently-Asked Questions About Bicycle Helmets.
• Our Bibliography of Helmet Documents has abstracts of over 500 helmet studies, papers, articles, etc. Most of it was done before 1996. We have references for other bibliographies with more recent publications as well.
• Our Toolkit for Helmet Promotion Programs has info for people who are launching a program.
• A page of information on How to Evaluate a Helmet Program.
• The Harborview study of best practices in helmet promotion programs.
• Our page for students researching a term paper on helmets.

The SafetyLit page.

SafetyLit produces a weekly digest with hundreds of journal articles abstracted every week. A search using the phrase "bicycle helmet" finds more than 300 journal articles and reports on the topic. A goldmine for researchers provided by the Center for Injury Prevention Policy & Practice at San Diego State University. You can subscribe for the weekly report, one of the most useful ways to keep current on journal articles in the helmet field. It has a section on Pedestrians and Bicycles, and one on Protective Headgear.

The TRIS page

You can research journal articles on bicycle helmets (and other subjects) on the TRIS Search Page. The Transportation Research Information Service has more than 400,000 books, journal articles, and technical reports on transportation research from the 1960's to the present. Put "bicycle and helmet" in the search window and it will return more than 145 references. The abstracts are sometimes disappointing, but the citations are very useful.

Evaluations

We have a page up on evaluations for helmet campaigns.

The US National Highway Traffic Safety Administration, part of DOT, has an extensive report called

Bicycle Helmet Use Laws: Lessons Learned from Selected Sites CD-ROM 2004

It includes lessons learned from Austin, Texas; Jacksonville and Duval County, Florida; the State of Maryland; the State of Oregon; Port Angeles, Washington, and Seymour, Connecticut. The web link actually has the entire CD if you click on "Table of Contents," and clicking on the "printer friendly version" link gets you a 219 page file in .pdf format that is actually the whole report.

Market Statistics

What little we know about the size of global or national helmet markets.

Our Search Function

You can use our site's search function for specific points that we may have missed.

What we do not have

We have put up everything we know on the web. Some major gaps remain, and you will not find information here on:

• Manufacturing techniques and materials used in helmets other than our page on foams and our page on helmet construction.
• Helmet marketing, other than our page on global market statistics.
• How to bring a helmet to market, or anything about business plans.
• Legal cases involving helmets or manufacturers.
• Data on college campus crashes or helmet use.

A Site by Helmet Sceptics

• The best site to begin investigating the scepticism some people hold about helmets is the Bicycle Helmet Research Foundation. They have a Policy Statement page that indicates where they are coming from, and links to other like-minded sites. The last site update was some time ago.

How to Cite or Reference Our Materials