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Published evidence sceptical of helmet effectiveness or promotion
See also: Contradictory evidence about the effectiveness of cycle helmets
Evidence support of helmet effectiveness
Helmet laws: What has been their effect?
Analysis

Papers Peer Criticism
Papers

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

Bicycle helmets and public health in Australia
Curnow WJ. Health Promotion Journal of Australia, 2008 Apr;19(1):10-15
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.

Changing pattern of child bicycle injury in the Bay of Plenty, New Zealand
Moyes SA. Journal of Paediatrics and Child Health, 2007;43:486-488
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)

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
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.

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.

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

Bicycle helmet legislation for the uptake of helmet use and prevention of head injuries (Cochrane Review)
Macpherson A, Spinks A. Cochrane Database of Systematic Reviews, 2007 issue 2 Art. No. CD005401.
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.
Suggestions for data and methodology to resolve conflict between case-control studies and trends.

Bicycle helmets and brain injury
Curnow WJ. Accident Analysis & Prevention, 2007 May;39(3):433-6.
Further response on the inadequacy of the Cochrane Review to provide evidence that helmets protect against brain injury.

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

Bicycle helmets: lack of efficacy against brain injury
Curnow WJ. Accident Analysis & Prevention, 2006 Sep;38(5):833-4.
Rebuttal of criticism of Curnow's 2005 paper, The Cochrane Collaboration and Bicycle Helmets.

Do enforced bicycle helmet laws improve public health?
Robinson DL. . BMJ, 2006;332:722.
There is no clear evidence of benefit from countries that have enforced the wearing of cycle helmets.

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
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.

Cycling and children and young people: a review
Gill T. National Children's Bureau, 2005. ISBN 1-904787-62-2
"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."

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.

Cycle helmets and road casualties in the UK
Hewson PJ. Traffic Injury Prevention, 2005;6(2):127-134
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.

Safety in numbers in Australia: more walkers and bicyclists, safer walking and bicycling
Robinson DL. 2005. Health Promotion Journal of Australia: 2005;16:47-51
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.

Investigating population level trends in head injuries amongst child cyclists in the UK
Hewson PJ. Accident Analysis & Prevention. 2005;37(5):807-815.
Head injuries are declining for child cyclists and pedestrians, but this is not related to helmet wearing data.

Heads up - the science of helmets
Walker B. Cycle, June/July 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.

The Cochrane Collaboration and bicycle helmets
Curnow WJ. Accident Analysis & Prevention. 2005;37(3):569-573
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.

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.

Risk compensation in children’s activities: A pilot study
Mok D, Gore G, Hagel B, Mok E, Magdalinos H, Pless B. Paediatr Child Health. 2004;9(5):327-330.
First empirical evidence of risk compensation when cycling. Injured children who had worn helmets rode faster and suffered more damage to their bikes.

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.

Head Injuries and Helmet Laws in Australia and New Zealand
Robinson DL. 2004
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

The efficacy of bicycle helmets against brain injury
Curnow WJ. Accident Analysis & Prevention. 2003,35:287-292
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.

Ride your bike: healthy policy for Australians
Rissel C. Health Promotion Journal of Australia. 2003;14(3):151-153
Emphasis on helmets has deterred many people from achieving the health benefits of cycling.

Hats off (or not?) to helmet legislation
Chipman ML. Canadian Medical Association Journal, 2002;166(5): 602
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.

Sikre skoleveje: En undersøgelse af børns trafiksikkerhed og transportvaner
Jensen SU, Hummer CH. Danmarks Transport Forskning, Rapport 3. 2002.
Helmet promotion may be responsible for a generation opting for driving instead of cycling.

Changes in head injury with the New Zealand bicycle helmet law
Robinson DL. Accident Analysis & Prevention: 2001 Sep;33(5):687-91
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.

A bicycling mystery: head injuries piling up
Barnes JE. New York Times, 29th July 2001
In the USA, the rate of cyclist head injuries has risen 10% although helmet use has soared and cycle use has declined.

Three lessons for a better cycling future
Wardlaw MJ. BMJ: 2000-12-23/30 n321 p1582-5
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.

Cycling: your health, the public’s health and the planet’s health
Bloomfield A. Making Cycling Viable Symposium, New Zealand, July 2000.
Opinion from neurosurgeon that helmets had made some head injuries worse. Need to reconsider issue as legislation has not delivered benefits predicted.

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

Helmet laws and health
Robinson DL, Acton CH. 1998. Injury Prevention: 1998;4:170-172
Complementary articles, for and against the effectiveness of helmets.

Trends in cycle injury in New Zealand under voluntary helmet use
Scuffham PA, Langley JD. Accident Analysis & Prevention: 1997;29(1):1-9
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.

Children and cycle helmets -- the case against
McCarthy M. Child Care Health Dev: 1996 Mar;22(2):105-11
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.

Head injuries and bicycle helmet laws
Robinson DL. Accident Analysis & Prevention: 1996 Jul;28(4):463-75
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.

Deaths of cyclists in London 1985-92: the hazards of road traffic
Gilbert K, McCarthy M. BMJ;1994:308(6943):1534-7
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.

Cycle helmets: the case for and against
Hillman M. Policy Studies Institute, 1993. ISBN 0-85374-602-8.
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.

On your head be it: helmets
Davis R. Chapter 11, Death on the streets, 1992. ISBN 0-948135-46-8
No conclusive benefit from helmets, but they do deflect attention away from dangerous driving.

Do cycle helmets prevent serious head injury?
McCarthy M, Illingworth C. 1992. BMJ: 1992 v305 p881-3
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.

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
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).

Pedal cycling accidents in Great Britain
Downing CS, Transport & Road Research Laboratory. Department of Transport 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.

Fatal injuries to bicycle riders in Auckland
Sage MD, Cairns FJ, Koelmeyer TD, Smeeton WMI. NZ Med J, Vol 98, No793, pp1073-1074, 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.
Peer Criticism

The following responses, citing evidence unsupportive of helmet use, are among those that have been published by the medical and professional press in the form of Letters to the Editor or short articles.

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