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Policy statement

Published evidence sceptical of helmet effectiveness or promotion


The papers below, published by the medical or professional press or presented at conferences, include analyses that cast doubt on the effectiveness of cycle helmets in reducing head injuries (at least serious head injuries), or on the wisdom of helmet promotion or laws.

A Bicycling Mystery: Head Injuries Piling Up

Barnes JE. New York Times, 29 Jul 2001. 2001.

In the USA, the rate of cyclist head injuries has risen 10% although helmet use has soared and cycle use has declined.

A cost-benefit analysis of BC's bicycle helmet law

Johns R. Velo City Global, Vancouver 2012. 2012.

The relative costs and moral issues of British Columbia's helmet law

A rational approach to pedal cyclist head protection  

Depreitere B. Catholic University of Leuven. 2004.

Bicycle helmets could not offer sufficient protection to the temporal area against lateral blows. There was no unequivocal beneficial effect of the helmets on the rotational acceleration of the head and on the vibration of the skull base.

Alcohol, bicycling and head and brain injury: a study of impaired cyclists' riding patterns

Crocker P, Zad O, Milling T, Lawson KA. American Journal of Emergency Medicine, 2010;28(1):68-72. 2010.

Alcohol use by cyclists is more strongly associated with head and brain injuries than cycle helmets. (Also subsequent letter by D. Robinson doi:10.1016/j.ajem.2010.02.019)

Assessment of current bicycle helmets for the potential to cause rotational injury  

StClair VJM, Chinn BP. Transport Research Laboratory, PPR213. 2007.

Australia's helmet law disaster  

Turner L. Institute of Public Affairs, IPA Review 2012(64):28-29. 2012.

Australian per capita cycling participation in 1985/6 and 2011  

Gillham C, Rissel C. World Transport Policy & Practice, 2012(May);18(3):5-10. 2012.

Bicycle helmet legislation for the uptake of helmet use and prevention of head injuries (Review)

Macpherson AK, Spinks A. Cochrane Database of Systematic Reviews, 2007 issue 2 Art. No. CD005401. 2007.

Unable to show that reductions in head injuries after helmet laws were result of helmets rather than decline in cycling.

Bicycle helmet legislation: Can we reach a consensus?  

Robinson DL. Accident Analysis & Prevention, 2007;39(1):86-93. 2007.

Suggestions for data and methodology to resolve conflict between case-control studies and trends.

Bicycle helmets - a case of risk compensation?  

Fyhri A, Bjørnskau T, Backer-Grøndahl A. Transportation Research Part F, 2012;15(5):612-624. 2012.

Helmet laws disproportionately discourage the safest cyclists, who are not speed-happy and who cycle without much cycling equipment. In this way the overall average risk per cyclist is increased and interventions such as helmet laws have no net benefit.

Bicycle helmets and accidental asphyxia in childhood

Byard RW, Cala A, Ritchey D, Woodford N.. Medical Journal of Australia, MJA 2011;194(1):49. 2011.

Accidental hanging still occurring due to cycle helmets when worn by children off their bikes.

Bicycle helmets and brain injury  

Curnow WJ. Accident Analysis & Prevention, 2007 May;39(3):433-6.. 2007.

Further response on the inadequacy of the Cochrane Review to provide evidence that helmets protect against brain injury.

Bicycle helmets and public health in Australia

Curnow WJ. Health Promotion Journal of Australia, 2008 Apr;19(1):10-15.. 2008.

After helmet legislation was introduced, rates of cycling declined sharply with loss of benefits for health, but the risk of casualty increased. Compulsion to wear a bicycle helmet is detrimental to public health in Australia.

Bicycle helmets: a scientific evaluation

Curnow WJ. Transportation Accident Analysis & Prevention, Nova Science Publishers, Chapter 6. 2008.

A detailed analysis of brain injuries, helmets and legislation

Bicycle helmets: lack of efficacy against brain injury  

Curnow WJ. Accident Analysis & Prevention, 2006 Sep;38(5):833-4.. 2006.

Rebuttal of criticism of Curnow's 2005 paper, The Cochrane Collaboration and Bicycle Helmets.

Bicycle-related head injury rate in Canada over the past 10 years  

Middaugh-Bonney T, Pike I, Brussoni M, Piedt S, Macpherson A. Injury Prevention, 2010;16:A228. 2010.

Although bicycle-related injuries are generally declining, this decline is not consistent, nor is it clearly associated with helmet laws.

Bicycling injury hospitalisation rates in Canadian jurisdictions: analyses examining associations with helmet legislation and mode share  

Teschke K, Koehoorn M, Shen H, et al. BMJ. 2015.

The purpose of this study was to calculate exposure-based bicycling hospitalisation rates in Canadian jurisdictions with different helmet legislation and bicycling mode shares, and to examine whether the rates were related to these differences.

Bicyclists, helmets and head injuries: a rider-based study of helmet use and effectiveness

Wasserman RC, Waller JA, Monty MJ, Emery AB, Robinson DR. American Journal of Public Health, 1988 Sep;78(9):1220-1. 1988.

Usually cited as a pro-helmet paper, nevertheless helmet wearers were 7 times more likely to have hit their heads than non-wearers.

Changes in head injury with the New Zealand bicycle helmet law  

Robinson DL. Accident Analysis & Prevention, 2001 Sep;33(5):687-91. 2001.

The large increase in helmet wearing as a result of the NZ helmet law has not led to any obvious change in head injuries over and above existing trends.

Changing pattern of child bicycle injury in the Bay of Plenty, New Zealand  

Moyes SA. Journal of Paediatrics and Child Health, 43(2007):486-488. 2007.

Since the New Zealand helmet law was enacted, childrens' injuries from bicycle use have increased but there has been a marked reduction in collisions with motor vehicles. This is the result of a change in the way bicycles are used by children. (This suggests that any reduction in head injuries post-law would be at least in part because children face less serious injuries as they now cycle much less in traffic)

Children and cycle helmets -- the case against  

McCarthy M. Child Care Health Dev, 1996 Mar;22(2):105-11. 1996.

Cycle helmets give very limited protection and shift the blame onto children if they are injured even though adult motorists are often at fault. 5 times as many child pedetrians die after road crashes than child cyclists.

Cycle Helmets

. BMA Board of Science and Education, ISBN 0-7279-1430-8. 1999.

The wearing of helmets by cyclists should not be made compulsory, but the wearing of helmets – preferably to the Snell B95 standard – should be encouraged.

Cycle helmets and road casualties in the UK

Hewson PJ. Traffic Injury Prevention, 2005;6(2):127-134. 2005.

There is no evidence that cycle helmets reduce the overall cyclist injury burden at the population level in the UK when data on road casualties is examined.

Cycle helmets: the case for and against  

Hillman M. Policy Studies Institute, ISBN 0-85374-602-8. 1993.

At best, helmets only marginally reduce a cyclist's chance of being fatally or serious injured. The balance of evidence does not suggest that a helmet law would reduce the level of head injuries. Similarly, encouraging voluntary helmet use is unlikely to reduce the risk of head injury. The primary means of reducing serious head injury is to create an environment in which crashes are less likely to occur.

Cycling and children and young people: a review

Gill T. National Children's Bureau. 2005.

"Those ... who cycle should be under no illusion that helmets offer reliable protection in crash situations where our lives may be in danger. Neither should we believe that widespread adoption of helmet wearing would see many fewer cyclists killed or permanently disabled. The evidence so far suggests otherwise."

Cycling: your health, the public's health and the planet's health  

Bloomfield A. Making Cycling Viable symposium. 2000.

Opinion from neurosurgeon that helmets had made some head injuries worse. Need to reconsider issue as legislation has not delivered benefits predicted.

Deaths of cyclists in London 1985-92: the hazards of road traffic  

Gilbert K, McCarthy M. BMJ, BMJ;1994:308(6943):1534-7. 1994.

30% of cyclists' deaths in outer London and 58% in inner London involve heavy good vehicles. Helmets do not address the source of danger in crashes where the injury is severe or fatal. Helmets restrict cyclists rather than motor vehicles.

Do cycle helmets prevent serious head injury?  

McCarthy M, Illingworth C. BMJ, 1992 v305 p881-3. 1992.

Cycling is safe, green and healthy. The main study supporting cycle helmet use is useless as policy guidance as it compared quite different groups of cyclists. Cycle helmets do not improve safety and place responsibility for injury protection on the victim.

Do cyclists have an exaggerated perception of the effectiveness of cycle helmets and the risks of cycling?  

Burton R. University of the West of England. 2008.

Drivers overtaking bicyclists: Objective data on the effects of riding position, helmet use, vehicle type and apparent gender  

Walker Ian. University of Bath. 2006.

Evaluating the health benefit of bicycle helmet laws  

de Jong P. Macquarie University NSW. 2009.

Net health costs of helmet laws greatly outweigh the safety benefits.

Evaluation of New Zealand's bicycle helmet law  

Clarke CF. New Zealand Medical Journal, 2012;125(1349). 2012.

A halving of cycle use may have led to around 53 additional premature deaths each year. At the same time cyclist injuries have more than doubled compared to pedestrians.

Extent and severity of cycle accident casualties

. Scottish Executive Social Research. 2005.

Fewer head and face injuries with helmets, but no effect on injuries serious enough to require hospital admission or other ongoing treatment.

Fatal injuries to bicycle riders in Auckland

Sage MD, Cairns FJ, Koelmeyer TD, Smeeton WMI. NZ Med J, Vol 98, No793, pp1073-1074, 1985. 1985.

"This study indicates that compulsory wearing of suitable safety helmets by cyclists is unlikely to lead to a great reduction in fatal injuries, despite their enthusiastic advocacy". Includes death of helmeted cyclist in simple fall without involvement of motor vehicle."

Hats off (or not?) to helmet legislation  

Chipman ML. Canadian Medical Association Journal, 2002 Mar 5;166(5):602. 2002.

Although the proportion of cyclists wearing helmets increased in Nova Scotia following helmet legislation and the number of head injuries fell, the main effect of the law was a large decrease in the number of people cycling.

Head injuries and bicycle helmet laws  

Robinson DL. Accident Analysis & Prevention, 1996 Jul;28(4):463-75. 1996.

The most notable effect of helmet laws in Australia has been to reduce cycling, and this may have generated a net loss of health benefits to the nation. The risk of dying from head injury per hour is similar for unhelmeted cyclists and motor vehicle occupants, and a helmet law for motorists has the potential to save 17 times as many lives as a cycle helmet law.

Head injuries and helmet laws in Australia and New Zealand

Robinson DL. 2005.

An assessment of the helmet laws. There is little benefit to either cyclists or the community from passing laws forcing cyclists to wear helmets. Rather than encouraging cyclists to wear helmets, the laws appear to have discouraged cycling, resulting in reduced health and fitness, but very little change in the head injury rate. Indeed, risks per cyclist seem to have increased, compared to what would have been expected without the law.

Heads up - the science of helmets

Walker B. Cycle, Jun/Jul 2005. 2005.

Helmets offer only limited protection in simple low-speed falls with no other vehicle involved. Helmet standards have declined greatly in recent years yet most helmets do not meet the standards to which they are accredited. The courts remain to be convinced that helmets can be relied upon to provide useful protection in most crashes.

Health on the move 2. Policies for health promoting transport

Mindell JS, Watkins SJ, Cohen JM. Transport & Health Study Group. 2011.

Cycling has great potential to assist public health programmes and reduce road danger. Fair comparison proves that the risks of cycling are within the range to which drivers and pedestrians are exposed. The most careful long-term studies do not reveal evidence of noticeable prevention of serious head injuries with rising helmet use.

Heat transfer variations of bicycle helmets  

Bruhwiler PA, Buyan M, Huber R, Bogerd CP, Sznitman J, Graf SF, Rosgen T. J Sports Sci, 2006 Sep;24(9):999-1011. 2006.

Lack of systematic understanding of the principles behind bicycle helmet ventilation, which varies considerably between helmets.

Helmet laws and health  

Robinson DL, Acton CH. Injury Prevention, 1998;4:170-172. 1998.

Complementary articles, for and against the effectiveness of helmets.

Helmet laws: creating consensus out of controversy and contradictions

Robinson DL. Velo City 2007. 2007.

Helmet legislation and admissions to hospital for cycling related head injuries in Canadian provinces and territories: interrupted time series analysis  

Dennis J, Ramsay T, Turgeon AF, Zarychanski R. British Medical Journal, BMJ 2013;346:f2674. 2013.

Injury rates from walking, gardening, weightlifting, outdoor bicycling and aerobics

Powell KE. Medicine & Science in Sports and Exercise, 1998;30:1246-1249. 1998.

Fewer people reported injuries from cycling than any of the other activities.

Intended and unintended consequences of youth bicycle helmet laws  

Carpenter CS,Stehr MF. Journal of Law and Economics, Vol 54 No2 May 2011. 2011.

In America, 650,000 fewer children ride bikes each year after helmet laws go into effect. Study has its weaknesses.

Investigating population level trends in head injuries amongst child cyclists in the UK

Hewson PJ. Accident Analysis & Prevention, 2005;37(5):807-815. 2005.

Head injuries are declining for child cyclists and pedestrians, but this is not related to helmet wearing data.

Making Vision Zero real: Preventing pedestrian accidents and making them less severe  

Erke A, Elvik R. TOI, Norwegian Centre for Transport Research, Report 889/2007. 2007.

There is evidence of increased accident risk per cycling-km for cyclists wearing a helmet. Meta analyses of helmet benefit are very likely affected by publication bias and methodological flaws. Increasing the amount of cycling would decrease accident risk.

New Zealand bicycle helmet law - do the costs outweigh the benefits?

Taylor M, Scuffham P. Injury Prevention, 2002;8:317-320. 2002.

No clear evidence from countries that have enforced the wearing of helmets  

Robinson DL. BMJ, 2006;332:722-725. 2006.

There is no clear evidence of benefit from countries that have enforced the wearing of cycle helmets.

On your head be it: helmets

Davis R. Death on the Streets chapter 11, ISBN 0-948135-46-8. 1992.

No conclusive benefit from helmets, but they do deflect attention away from dangerous driving.

Pedal cycle accidents in Great Britain

Downing CS. Ways to Safer Cycling conference. 1985.

Cycle helmets have potential to reduce cyclist casualties by less than 1%, compared with 27% for developments in training and engineering.

Public Bicycle Share Programs and Head Injuries  

Graves Janessa M., Pless Barry, Moore Lynne, Nathens Avery B., Hunte Garth, Rivara Frederick P.. American Journal of Public Health. 2014.

American Journal of Public Health 104, e106_e111

Publication bias and time-trend bias in meta-analysis of bicycle helmet efficacy: A re-analysis of Attewell, Glase and McFadden, 2001

Elvik R. Accident Analysis & Prevention, 2011;43(3):1245-1251. 2011.

Attewell et al influenced by publication and time-trend biases. When controlled for, the protective effects of helmets are smaller. Adding new studies, no overall benefit of helmets found.

Reducing bicycle accidents: a re-evaluation of the impacts of the CPSC bicycle standard and helmet use

Rodgers GB. Journal of Products Liability, 1988 ,11:307-317. 1988.

The largest ever cycling casualty study involving over 8 million cases of injury and death to cyclists in the USA over 15 years. It concluded that there was no evidence that hard shell helmets had reduced the head injury and fatality rates. Moreover, there was a significant positive correlation between fatalities and helmet use (i.e. helmeted riders were more likely to be killed).

Ride your bike: healthy policy for Australians  

Rissel C. Health Promotion Journal of Australia, 2003;14(3):151-153. 2003.

Emphasis on helmets has deterred many people from achieving the health benefits of cycling.

Risk compensation and bicycle helmets  

Phillips RO, Fyhri A, Sagberg F. Risk Analysis, 2011; Mar 18. 2011.

Field study, the findings of which are consistent with the notion that those who use helmets routinely perceive reduced risk when wearing a helmet, and compensate by cycling faster.

Safety in numbers in Australia: more walkers and bicyclists, safer walking and bicycling

Robinson DL. Health Promotion Journal of Australia, 2005;16:47-51. 2005.

Following the introduction of compulsory helmets for cyclists, there was a 30% reduction in cycling and it was associated with a higher risk of death or serious injury per cyclist, outweighing any benefits of increased helmet wearing.

Serious injury due to land transport accidents, Australia, 2003-04  

Berry JG, Harrison JE. Australian Institute of Health and Welfare, Inj Res & Stat Series No.38. 2007.

Helmeted cyclists have about the same percentage of head injuries (27.4%) as unhelmeted car occupants and pedestrians (28.5%). Wearing a helmet seems to have no discernible impact on the risk of head injury.

Sikre skoleveje: En undersogelse af borns trafiksikkerhed og transportvaner  

Jensen SU, Hummer CH. Danmarks Transport Forskning, Rapport 3, 2002. 2002.

Helmet promotion may be responsible for a generation opting for driving instead of cycling.

Specific patterns of bicycle accident injuries - An analysis of correlation between level of head trauma and trauma mechanism  

Möllman FT, Rieger B, Wassmann H. DGNC Köln. 2004.

No significant difference concerning the level of head-trauma due to bicycle accident between cyclists wearing a helmet and others.

The Cochrane Collaboration and bicycle helmets  

Curnow WJ. Accident Analysis & Prevention, 2005;37(3):569-573. 2005.

Review takes no account of scientific knowledge of types and mechanisms of brain injury and is not a reliable guide to the efficacy of helmets and to interventions concerning their use.

The effect of bicycle helmet legislation on bicycling fatalities  

Grant D, Rutner SM. Journal of Public Policy, 2004;23(23). 2004.

Fatalities reduce 15% in the long term, but this can't be only because of legislation. Nationally a 12% reduction in fatalities was associated with a 21% reduction in bicycle use.

The effects of bicycle helmet legislation on cycling-related injury: the ratio of head to arm injuries over time  

Voukelatos A, Rissel C. Australasian College of Road Safety, ACRS 2010;21(3):50-55. 2010.

Helmets were not the main reason for the drop in head injuries in Australia since helmet laws were introduced. General improvement in road safety from random breath testing and other measures were probably the cause.

The effects of wearing protective helmets on attentional processes in young cricketers

Neave N, Emmett J, Moss M, Scholey A, Wesnes K. Northumbria University, Cognitive Science Unit. 2004.

The wearing of cricket helmets slows reaction time due to heating the brain

The efficacy of bicycle helmets against brain injury  

Curnow WJ. Accident Analysis and Prevention, 2003,35:287-292. 2003.

The meta-analysis of case-control studies does not provide scientific evidence that such helmets reduce serious injury to the brain as it does not distinguish injuries caused through fracture of the skull and by angular acceleration.

The health impact of mandatory bicycle helmet laws  

de Jong P. Risk Analysis. 2012.

In jurisdictions where cycling is safe, a helmet law is likely to have a large unintended negative health impact. In jurisdictions where cycling is relatively unsafe, helmets will do little to make it safer and a helmet law, under relatively extreme assumptions, may make a small positive contribution to net societal health. The model serves to focus the mandatory bicycle helmet law debate on overall health.

The health risks and benefits of cycling in urban environments compared with car use: health impact assessment study  

Rojas-Rueda D, de Nazelle A, Tainio M, Nieuwenhuijsen MJ. British Medical Journal, BMJ 2011; 343:d4521 . 2011.

The health benefits of cycling exceed the risks by 77:1, even in a busy city where few people wear helmets.

The impact of compulsory cycle helmet legislation on cyclist head injuries in New South Wales, Australia: A rejoinder  

Rissel C. Accident Analysis & Prevention, 2012;45:107-109. 2012.

This paper challenges Walter, Olivier, Churches and Grzebieta, 2011 detailing many shortcomings that are said to make its conclusions invalid.

The possible effect on frequency of cycling if mandatory bicycle helmet legislation was repealed in Sydney, Australia: a cross sectional survey  

Rissel C, Wen LM. Health Promotion Journal of Australia, 2011; 22: 178-83. 2011.

The potential for cycle helmets to prevent injury - a review of the evidence

Hynd D, Cuerden R, Reid S, Adams S. Transport Research Laboratory, PPR446. 2009.

Despite attempts to manipulate the results, one of the largest reviews of the evidence has not been able to find any reliable evidence that helmets have benefited cyclists

The risk compensation theory and bicycle helmets  

Adams J, Hillman M. Injury Prevention, 2002;8:e1-e1. 2002.

Part of debate between authors pro- and against the theory of risk compensation.

Three lessons for a better cycling future  

Wardlaw MJ. BMJ, 2000-12-23/30 n321 p1582-5. 2000.

Cycling has a fine safety record; driving does not. The statistical wrangle over cycle helmets is a side issue; helmet promotion engenders the impression that cycling has become much more hazardous than driving, which deters cycling and increases risk for those who continue to cycle.

Trends in cycle injury in New Zealand under voluntary helmet use  

Scuffham PA, Langley JD. Accident Analysis and Prevention, 1997 Jan;29(1):1-9. 1997.

In the 12 months prior to the introduction of a helmet law, helmet wearing in New Zealand rose to 84% for primary school children, 62% for secondary school children and 39% for adults. However, there was no evidence that increased helmet use had resulted in fewer serious head injuries.

Trends in helmet use and head injuries in San Diego County: The effect of bicycle helmet legislation

Ming J, Gilchick RA, Bender SJ. Accident Analysis & Prevention, 2006;38(1):128-134. 2006.

No significant reduction in serious head injury over study period. Serious head injuries rose as helmet use grew fastest. Although one of the most popular areas for cycling in the USA, the incidence of serious head injury was low.

Understanding children's injury-risk behavior: Wearing safety gear can lead to increased risk taking  

Morrongiello BA, Walpole B, Lasenby J. Accident Analysis & Prevention, 2007 May;39(3):618-23. 2007.

Children went more quickly and behaved more recklessly when wearing safety gear (including helmets) than when not wearing gear providing evidence of risk compensation.

Peer criticism

The peer criticisms that follow are among those that have been published by the medical or professional press in the form of Letters to the Editor or short articles.

Bicycle helmets benefits might be overestimated

Robinson DL. American Journal of Emergency Medicine, 2010;28(4):527-528.

Response to Crocker et al, 'Alcohol, bicycling, and head and brain injury'.

Cycle helmet law not properly assessed  

Clarke CF. Injury Prevention, letters on-line. Dec 2010

Evidence on cycle helmets is contested, ambiguous and inconclusive  

Ward P. Injury Prevention e-letters 2006

Good data and constructive debate can help resolve controversial issues  

Robinson DL. Injury Prevention e-letters 2006.

Do enforced bicycle helmet laws improve public health?

BMJ Rapid Responses 2006

Rapid responses - General debate
Rapid responses to Robinson article
Rapid responses to counter-article

Helmets not helpful - an example of poor public policy

Curnow WJ. Health Promotion Journal of Australia 2005;16(2):160

Also letter from Clarke C

Helmet legislation is dangerous for cyclists  

Trottier TA. Canadian Medical Association Journal Electronic letters 11 Apr2005

Helmets for cyclists and the ethics of legislation  

Rawlins Sir J, Surgeon Vice-Admiral. Journal of the Royal Society of Medicine 2004;97:556-7

Effectiveness of cycle helmets and ethics of legislation  

Wardlaw MJ. Journal of the Royal Society of Medicine 2004;97:409-10

Effectiveness of cycle helmets and ethics of legislation  

Burdett A. Journal of the Royal Society of Medicine 2004;97:503

Reasons for trends in cyclist injury data  

Robinson DL. Injury Prevention 2004;10:126-127

Only wholeness leads to clarity  

Wardlaw MJ. Archives of Disease in Childhood 2004;89:692-3

Helmet laws and cycle use  

Robinson DL. Injury Prevention 2003;9:380-3

Butting heads over bicycle helmets  

Wardlaw MJ. Canadian Medical Association Journal 2002;167:337-9

Also letter by DeMarco TJ.

The risk compensation theory and bicycle helmets  

Adams J, Hillman M. Injury Prevention, 2001;7:343

Cycle helmets: Risk taking is influenced by people's perception of safety and danger  

Hillman M, Adams J et al. British Medical Journal 2001;322:1063-5

Also letters by Godefrooij T, Jacobsen P, Wardlaw MJ

Changes in head injury with the New Zealand bicycle helmet law  

Robinson DL. Accident Analysis and Prevention 2001;33:687-91

Bicycle helmets - it's time to use them  

BMJ electronic letters 2000 - 2002

23 peer responses to an editorial about cycle helmets. Most responses sceptic of their value.

Cyclists should wear helmets  

Davis A, Waterston T, Robinson DL, Keatinge R, Hillman M, Hall GH, BMJ 1997;314:69

Protection afforded by cycle helmets  

Keatinge R, Parry R. Protection afforded by cycle helmets. BMJ, 1994;309:1441 (26 Nov)

See also