We tend to be less cautious

Wearing a safety device creates a feeling of safety. This makes us less cautious. This well documented behavior is called risk compensation. We tend to take more risks when wearing safety equipment.

Risk compensation is the tendency to take more risks when wearing safety equipment.

The New York Times reported an odd increase in injuries after bicycle helmets became popular in the US:

“the rate of head injuries per active cyclist has increased 51 percent just as bicycle helmets have become widespread. …

the increased use of bike helmets may have had an unintended consequence: riders may feel an inflated sense of security and take more risks. …

The helmet he was wearing did not protect his neck; he was paralyzed from the neck down. …

”It didn’t cross my mind that this could happen,” said Philip, now 17.

”I definitely felt safe. I wouldn’t do something like that without a helmet.” ”

Safety experts recognise the role of risk compensation.
From the New York Times article:

”People tend to engage in risky behavior when they are protected,” he said. ”It’s a ubiquitous human trait.”

Even cyclists who discount the daredevil effect admit that they may ride faster on more dangerous streets when they are wearing their helmets.”

A study in Accident Analysis and Prevention found that children are also affected by risk compensation:

“Results indicated that children went more quickly and behaved more recklessly when wearing safety gear than when not wearing gear, providing evidence of risk compensation.”

A 1989 study found that helmet wearers were 7 times more likely to have accidents.

Risk compensation is an unconscious phenomenon.
We may not be aware of it.
Yet it affect the way we ride, the way we approach risks.

We are more likely to be hit by cars

Risk compensation also affects motorists.
Motorists tend to be less careful around helmeted cyclists. Drivers assume helmeted cyclists are “protected”.

A study published by the University of Bath in the UK reported that cars leave less room to helmeted cyclists:

“Bicyclists who wear protective helmets are more likely to be struck by passing vehicles”

Injuries tend to be more severe

Another subtle aspect of risk compensation is that we tend to ride faster.
A study in the Risk Analysis international journal found that:

“those who use helmets routinely perceive reduced risk when wearing a helmet, and compensate by cycling faster”

In case of an accident, the higher speed results in more severe injuries.

There is a greater risk of the head hitting the road

In the event of an accident, helmets increase the risk of the head hitting the road.  Helmets increase the volume/size of contact area of the head. Helmeted riders are more than twice as likely to hit their head in an accident, with more impacts to the sides. Post-crash studies found that most helmets show impacts to the side,where a bare head is protected by the shoulders.

Helmets increase the volume of the head, doubling chance of the head hitting the road in an accident;

A 1988 study reports that helmeted riders hit their heads seven times more often than un-helmeted riders.

We can suffer severe brain injury

In 1960, people believed that brain injury was due to linear acceleration, from the head hitting a wall for example. This belief has shaped the design of bicycle helmets.

Since, scientific research has shown that the main cause of brain injury is diffuse injury, caused by the head turning quickly. The skull may be intact, but there can severe internal brain injury. This article reports from a surgeon who operates on cyclists:

” “The ones with brain swelling, that’s diffuse axonal injury, and that’s bad news” …

the whole brain is shaken up, creating many little tears in its inner structure …

Such patients undergo personality change, can contract epilepsy and have difficulty controlling their anger. They might become unemployable. Depression is a common accompaniment to brain injury. Rosenfeld sees patients’ families shattered, too. “They’re never the same. It often leads to marriage disharmony and family breakdown.” …

Rosenfeld’s opinion is candid. “I don’t know if [helmets] do much to protect the inner part of the brain,” “

Research has found that helmets can increase rotational acceleration:

“The non-shell helmet did in all trials grab the asphalt surface, which rotated the head together with the helmet. The consequences were in addition to the rotating of the head, a heavily bent and compressed neck, transmitted on through the whole test dummy body after the impact.  …

This gives an average angular acceleration of 20800 rad/s² for rotating the head from 0 to 0.26 rad during the 5 ms. Löwenhielm proposes 4500 rad/s² to be the maximum angular acceleration that can be tolerated for a limited time period”

Helmets were found to amplify rotational acceleration to four times higher than the tolerable maximum.

The larger head volume amplifies rotational acceleration. A 3cm increase in helmet circumference increases rotational acceleration by 150%:

“the 3000rad/s² to 8500rad/s² measured during abrasive and projection oblique tests with size 54cm (E) helmeted headforms. However, for the most severe cases using a size 57cm (J) headform, rotational acceleration was typically greater than 10,000rad/s² and increased to levels of 20,000rad/s², a level at which a 35% – 50% risk of serious AIS3+ injuries is anticipated.”

The volume of a bicycle helmet amplifies rotational acceleration to dangerous levels where severe brain injury can occur.

A New Zealand doctor reports:

“cycle helmets were turning what would have been focal head injuries, perhaps with an associated skull fracture, into much more debilitating global head injuries”

In Canada, the length of stay in hospital increased increased following helmet laws, from 4.3 days to 6.9 days. The number of serious head injury admissions increased by 46%.

Contrary to popular belief, helmets are not designed to protect against brain injury.
However, they can increase rotational acceleration, causing severe brain injury.

What a load of rubbish!

This might sound like a load of rubbish to cyclists who wear helmets. Some believe their helmet saved their life. Few consider they may have fewer accidents without a helmet.

Cycling injuries rose dramatically after a helmet law was introduced in Australia.

The rate of cycling injuries tripled after Australia introduced a helmet law.

You might feel safer wearing a helmet.
However that doesn’t mean you are safer.

In 1993, a team of researchers conducted lab experiments on bicycle helmets. The purpose was to measure the chin strap forces in accidents. The researchers were shocked by what they found. They found that helmets can seriously damage cyclists neck:

“The non-shell helmet did in all trials grab the asphalt surface, which rotated the head together with the helmet. The consequences were in addition to the rotating of the head, a heavily bent and compressed neck, transmitted on through the whole test dummy body after the impact.”

A related incident was reported in the New York Times:

“In August 1999, Philip Dunham, then 15, was riding his mountain bike in the Great Smoky Mountains National Park in North Carolina and went over a jump on a trail. As he did, his back tire kicked up, the bike flipped over and he landed on his head. The helmet he was wearing did not protect his neck; he was paralyzed from the neck down.

Two years later, Philip has regained enough movement and strength in his arms to use a manual wheelchair. He has also gained some perspective. With the helmet he felt protected enough to ride off-road on a challenging trail, in hindsight perhaps too safe.

”It didn’t cross my mind that this could happen,” said Philip, now 17. ”I definitely felt safe. I wouldn’t do something like that without a helmet.”

Look at a bicycle helmet. It has been designed with comfort in mind. It is made of light weight material that grip the road on impact rather than glance off it (as is the case with motorcycle helmets).

The increase in the volume of the head, coupled with the gripping of the road surface, means that when a head comes into contact with the ground at speed, the head or body is rotated, sometimes snapping the spinal cord.

This is a dangerous aspect of cycling with a helmet. You run the risk of paraplegia or quadriplegia.

Bicycle helmets can get caught in accidents, damaging the neck, as reported in the Canberra Times:

“Lud Kerec was training for one of the toughest triathlon events in the world when he smashed head-on into another cyclist in the ACT’s north. …

”It is unlikely I’ll walk one day,” said the 65-year-old Mr Kerec, who takes half a cup of drugs a day. He was nearly garrotted by the strap from his own helmet after he believes it became tangled in the other bike and yanked his head back.”

In 2010, a helmeted cyclist died in Wanniassa (Australian Capital Territory). The pathologist’s report to the coroner shows that that he suffered diffuse axonal injury. Diffuse axonal injury is a severe type of brain injury aggravated by bicycle helmets.

These are not unique incidents. Many studies have reported increased neck injuries from bicycle helmets. For example, research by McDermott et al. (Trauma, 1993, p834-841) found 75% more neck injuries among helmet wearers.

Why don’t bicycle helmets have warnings about the risk of permanent disability while wearing them?
This is a serious risk that people should be aware of.

When wearing “protection” results in more injuries,
perhaps we need to look deeper about what is really going on.

Wearing a helmet can make us feel safer.
However feeling safe is different than being safe.

After a helmet law was introduced in Australia, many cyclists insisted their helmets had saved them.

Yet cycling injuries increased.

How can both be true at the same time?

They can be true at the same time if there is a large increase in accidents.

From the injury data, this is what happened.

This is the paradox of bicycle helmets. People believe their helmets saved them, despite suffering more injuries. The irony is that the helmet saved them from accidents that may not have happened without the helmet.

It seems “obvious” & “intuitive” that wearing a helmet should reduce injuries.
Yet sometimes our intuition can be wrong.
Sometimes there are consequences we cannot see that are more harmful than what seems obvious.

More helmets –> more accidents –> more injuries

This surprising result not unique to Australia. Other countries have experienced increased injuries following an increase in helmet wearing.

In the US, a rise in helmet wearing led to more head injuries, according to the New York Times

the rate of head injuries per active cyclist has increased 51 percent just as bicycle helmets have become widespread…

the increased use of bike helmets may have had an unintended consequence: riders may feel an inflated sense of security and take more risks…

”People tend to engage in risky behavior when they are protected,” he said. ”It’s a ubiquitous human trait.”

Even cyclists who discount the daredevil effect admit that they may ride faster on more dangerous streets when they are wearing their helmets.

In New Zealand, a study found that injuries more than doubled following a bicycle helmet law.

A 1989 US study found that helmet wearers were 7 times more likely to have accidents.
How can a flimsy piece of polystyrene compensate for 7 times more accidents?

A strange helmet culture

Riding in Australia is a unique experience. Cycling accidents are considered normal. There is a special word for a bicycle accident, called a “stack”. Many cyclists have tales of their frequent “stacks”, and how each stack reinforce their belief in helmets. They would never ride without a helmet. Cycling is far too dangerous, even suicidal, according to a doctor from Melbourne:

riding a bicycle on Melbourne’s roads … is “verging on suicide”

It is a strange ideology, where helmets and accidents justify each other.
Cyclists wear helmets because they have frequent accidents.
Wearing a helmet increases the risk of accidents.

Contrast this with countries that do not mandate helmets, like the Netherlands.
Accidents are rare.
Cyclists have little fear of accidents.
Cycling is safe.

Which philosophy is safer?

1. Accident avoidance: no helmets, few accidents. The Netherlands
2. Accident protection: many accidents protected by helmets. Australia.

Australia cycling serious injury rate is 22 times greater than in the Netherlands:

Can bicycle helmets compensate for more accidents?

Choosing to wear a helmet seems a like “No brainer“. Such an obvious “precaution”.

Choosing not to wear a helmet is a more subtle decision.
It requires paying attention to what cannot easily been seen, rather than what seems “obvious”.
It requires an understanding of how helmets affect the risk of accidents.
It requires comparing a higher risk of accident with protection from polystyrene. 

It feels safer to wear a helmet. Yet the evidence indicates it may not be safer.

The paradox is: feeling safe is not the same as being safe.

The US government has dropped its claim that bicycle helmets reduce 85% of head injuries. The claim came from “research” conducted by helmet advocates in 1989. Many researchers have tried to replicate its results, but have been unable to do so. Amid severe criticism, the authors had to re-work their data, and arrived at a lower effectiveness rate.

This invalid claim is often quoted by people eager to push helmets. The US government had quoted the claim on its web site.

In 2013,  the US Department of Transportation agreed to delete the claim. This followed a petition lodged under the Federal Data Quality Act. The Data Quality Act requires information on federal web sites to be accurate and supported by appropriate research.

This was first reported by the Washington Area Bicyclsists Association. This followed its successful campaign against a bicycle helmet law in Maryland in early 2013.

US helmet manufacturer Riddell had to pay US$3 millions in compensation to an injured football player. Rhett Ridolfi suffered severe brain damage, as well as paralysis, despite wearing a helmet. A Colorado jury found Riddell negligent in failing to warn players about concussion.

This is one of many lawsuits about brain injury while wearing a helmet. The injured person lawyer said:

“If they had told the truth, and said, ‘You have a 50 percent change of getting a concussion with this helmet,’ what mother or father would let their kid play football in a Riddell helmet? And you can still buy this helmet today.”

Helmets provide the illusion of protecting against brain injury. Helmets cannot protect against rotational acceleration, the principal cause of brain injury. Report from the Toronto Star:

“Increasingly, what helmets have become are talismans. Riddell (and every other manufacturer) understands that no space-age resin, no lightweight polymer, no amount of high-tech bafflegab is going to fully protect you if you nail something hard and fast at just the wrong angle. They manufacture the illusion of full protection …

What they’re selling is witchcraft. The fault here does not lie with the manufacturers. It lies somewhere within the culture. …

There is very little difference between wearing a helmet and wearing a piece of the true cross. Both are faith objects. The power of any talisman is that its protective aura is self-reinforcing. As long as you aren’t hurt while you’re wearing it, one presumes the talisman takes the credit. …

the surest way to protect against brain injury is to either engage in pastimes that
A) don’t require helmets or
B) have adapted themselves to relatively safe, helmetless participation. …

With the helmet goes a misplaced sense of invincibility.”

As Jerry Seinfield noted, a key issue is the culture surrounding helmets:

Bicycle helmets have the same deficiency. Additionally, they can increase brain injury:

“Protecting the brain from injury that results in death or chronic disablement provides the main motivation for wearing helmets. Their design has been driven by the development of synthetic polystyrene foams which can reduce the linear acceleration resulting from direct impact to the head, but scientific research shows that angular acceleration from oblique impulse is a more important cause of brain injury. Helmets are not tested for capacity to reduce it and, as Australian research first showed, they may increase it.“

Helmets have been promoted by claiming they protect against brain injury. This can lead to people overestimating their benefit, taking more risks. As reported in the New York Times:

“the increased use of bike helmets may have had an unintended consequence: riders may feel an inflated sense of security and take more risks. …

The helmet he was wearing did not protect his neck; he was paralyzed from the neck down. …

”It didn’t cross my mind that this could happen,” said Philip, now 17.

”I definitely felt safe. I wouldn’t do something like that without a helmet.” “