How to protect your brain by not wearing a helmet

[Steady rider]

For New Zealand 5yo+ages, the data in Table 3 above shows the accident rate per million hours increased from 31.35 to 69.38. This related to all accidents involving motor vehicles and for "other" reasons, probably mainly falls and riding into objects or stationary vehicles. For those involving only motor vehicles it did not change very much, roughly eight per million hours to seven per million hours. Accidents due to "other" increased substantially from approximately 23 to 63 per million hours. The 23 accidents per million hours is approximately one per 43,000 hours of cycling on average. If cycling 10 hours per week, this would equate to once in 82 years on average. The disadvantages to helmets and increased risk taking only needs to be minute to increase the accident rate and exceed the expected benefits in a proportion of accidents.

see link page 1, page 13
https://www.researchgate.net/publicatio ... jury_rates

Increasing the accident risk could result in extra falls monthly, whereas the expected benefits could be once in so many years.

[pjclinch]

So you describe risk compensation again (from machinery) which I've acknowledged, but you also employ those advantages because you feel safer to do so, even if you have the best brakes in the world and the grippiest tyres, you won't do so unless you feel safer from going at the faster speeds, not wearing/wearing a helmet has a significant influence on that decisin making, riding to the max and in fact beyond.

Even still the grip of the tyres is not enough for the modern brakes/rider on the edge, only today in the Dauphine a rider went too fast into a corner and slid out, this was moments after David Miller had spouted a loud of nonsense regards how many lives helmets had saved in the pro ranks which clearly he has no idea about since the number of deaths and injuries post helmet wearing has increased.

As it happens I've slid out on a bend, and I wasn't even wearing a helmet and wasn't racing or getting paid: I just wanted to see if I could get round it on a particular line (thought I could, I was wrong). The point here is it that helmets are one of a number of things that will encourage riders to go closer to their perceived Red Line, but you continue to paint them as particularly significant above and beyond other things. For example, your implication that riders ride closer in the pro peloton with their helmets, and then say there are more accidents despite the other risk compensation factors while it's entirely likely it's because of them.

Take the helmets off and watch pro racing and indeed amateur/enthusiast riding become safer, address the issue of people operating killing machines and that improves a huge chunk more.

When I stopped wearing a helmet I slowed down... and then I got used to riding without one again and got back to going as fast as I was happy to go (slower than when I was in my teens and 20s, unhelmeted, in fact). After a month or so there was no discernible difference, because even in a helmet I had nothing to gain from crashing. For a racer the goal is to win the race. The closer you go to the limits the better your chances of winning, if you get it wrong and crash you're far less likely to. Mechanical improvements give a genuine ability to control a bike better and thus take it close to the line, but the closer you get the more chance of getting it wrong.

I would be very surprised if helmets had significantly more effect on risk taking than a more sure-footed ride, but you persist in singling them out for disproportionate blame. How much does a World Tour team leader get paid? Do you think that might factor in the willingness to go round bends quicker? I'm quite sure it does, but it's off your radar because it's not a helmet.

Pete.

[gregoryoftours]

Hi,
I fell off on black ice and hit the side of my head on a relatively solid ground.
I reckon I suffered mild concussion for several days.
This is the first time in 52 years riding.
The helmet was damaged, the argument goes that if I was not wearing a helmet my head wouldn't have come anywhere near the ground.

These sort of things are for once-in-a-lifetime experience not your every day one.
You pays your money and takes your choice.
Incidentally I landed on my hip too after a few minutes I struggled to stand and was a real challenge to get home using just one leg powering. Several x-rays and couldn't walk for several weeks without crutches.
Without the helmet I probably would've needed and ambulance, this is just my opinion, my head collision Was not recorded anywhere, how many are actually recorded when someone damages their helmet?

I had exactly the same experience a few years ago, washing out suddenly on black ice and going down hard on the front/side of my head and hip. I came to the same conclusion as you. It was suggested that I couldn't know that my head would have hit the ground if I hadn't been wearing a helmet, and that my own choice to wear a helmet or not shouldn't be influenced by the experience because it was anecdotal evidence! It was a bit ridiculous to be honest. I would invite those who suggested that my head would probably not have hit the ground to aim a hard headbutt at a wall and pull the blow starting deceleration at 2cm distance from the bricks!

I often don't wear a helmet and think that everybody should be free to choose, and in many situations a helmet might not help or even be harmful. But in that instance I have absolutely no doubt that the helmet saved me from a more serious injury.

[gregoryoftours]

It's a hard one. I fell off a couple of weeks ago and banged the side of my helmet on a kerb. But would it have happened if I wasn't wearing a helmet? - a helmet makes your head bigger.

You should have put your hands down to break your fall (even babies do that when they lose their balance
trying to walk) and wore protection for your palms to prevent them from being damaged.

And have a nice broken collarbone! The classic MTB hands out injury.

[Steady rider]

I would invite those who suggested that my head would probably not have hit the ground to aim a hard headbutt at a wall and pull the blow starting deceleration at 2cm distance from the bricks!

It is probably the wrong way to view the situation. see Diagram A, most falls are to the side and there would likely be a short time period to move the head away from the expected impact area.
http://www.ta.org.br/site/Banco/7manuai ... helmet.pdf

[Jdsk]

It is probably the wrong way to view the situation. see Diagram A, most falls are to the side and there would likely be a short time period to move the head away from the expected impact area.

This "Diagram A"?

Jonathan

[Steady rider]

Yes Diagram A,
Clarke discuses impacts in a later paper, page 42 or 45.
http://www.cycle-helmets.com/au-assessment-2015.pdf

4
Vic Roads refers to:
"A 2013 study investigated the factors, including helmet use, that contribute to head linear and angular
acceleration in bicycle crash simulation tests. It was found that helmet use was the most significant factor in reducing the magnitude of head and brain injury. The study reinforces the benefits of wearing a bicycle
helmet in a crash. It also demonstrated that helmets do not increase angular head acceleration, as some
researchers have claimed. (Andrew S. McIntosh , Adrian Lai & Edgar Schilter (2013): Bicycle Helmets:
Head Impact Dynamics in Helmeted and Unhelmeted Oblique Impact Tests, Traffic Injury Prevention, 14:5,
501-508) (External link)

The 2013 McIntosh et al study tested helmets for impact acceleration levels, lateral and rotational, for helmeted v non-helmeted and reported that both indicated a benefit from wearing helmets. However, it failed to account for various additional factors. Robinson 1996 reported:
"Assuming the observed helmet wearing was typical of the cyclists' regular habits, head injury rates in
helmeted and non helmeted cyclists (7/476 vs 0/49) were therefore not significantly different (p < 0.55), but the incidence of hitting their heads in a cycling accident was most significantly higher for helmet wearers (8/40 vs 13/476 i.e. 20% vs 2.7%; p < 0.00001)."
McIntosh et al failed to take account that helmet wearers had been reported at a have a higher rate of impact than non-wearers. Also, they failed to take full account of the difference in duration of impact for rotational accelerations. The Wayne State Tolerance Curve for head injury indicates higher accelerations can be tolerated for shorter durations214. The duration of impact for non-helmeted was approximately 3 ms and 8ms for helmeted. The product of rotational acceleration and duration are important elements of evaluating head injury215.
McIntosh et al results indicate a rotational product of approximately 8 krads/s² for 8 ms for helmeted (Fig 3), (64 krad/s²-ms) vs for non-helmeted (Fig 4),13 krad/s² for 3 ms (39 krad/s²-ms). In effect, their results show that helmeted may be more at risk from rotational acceleration by the extended time involved. Consequently their conclusions may not be reliable. The research also fails to take account of a major report by St Clair and Chinn [1] who conducted tests showing that helmeted can experience rotational acceleration levels up to 20 krad/s² by impacting a central vent position. McIntosh et al failed to test for central vent impacts.

[Jdsk]

It is probably the wrong way to view the situation. see Diagram A, most falls are to the side and there would likely be a short time period to move the head away from the expected impact area.

What does Diagram A have Io do with either the distribution of falls or the time taken to fall?

What do the +39% and +89% represent?

Thanks

Jonathan

[Mick F]

Diagram A is proportionately way out.

In real life, a helmet is nearly four inches in diameter more than the head diameter ......... ie perhaps 2" thick if you count the plastic head-band and padding plus the polystyrene.

My final helmet went to the local recycling centre. They couldn't recycle it, so it went into the skip and I never looked back.

[NATURAL ANKLING]

Hi,

Diagram A is proportionately way out.

In real life, a helmet is nearly four inches in diameter more than the head diameter ......... ie perhaps 2" thick if you count the plastic head-band and padding plus the polystyrene.

2 inches is a gross miss representation of reality.
I've just measured mine and it comes out at about 26.5 mm including the headband?

[Mick F]

Can't argue other than use my experience of the size.
I no longer have a helmet to measure ................ and I don't want one either.

Maybe it's me?
Maybe it's the size of my head?

Old fashioned sizing, I have a six and threequarters head size. Quite small.
Buy a helmet to fit, they come in Small, Medium, and Large, and "Male" as well.
I always needed a Small Male.

Therefore, the straps internally needed adjusting to their minimum which meant the helmet outer periphery was HUGE compared to my (small) head.

Hence my statement, but I can't measure to prove it, but 2" wider to the sides was about it.
4" diameter more than my six and threequarters.

[Mick F]

Photo of me wearing my last helmet in 2010 at JOG.

Note two things.
I had hair ....... though white.
My head diameter is 6.75"
Helmet outside diameter .............. using proportions?

Looking at the piccy on my screen as it is, my head is 62mm ish across, and the helmet is 85mm ish across.
ie the helmet is 35% wider?

6.75 inches plus 35% = 9.11 inches
So, the helmet is just over inch thick though it looks (and felt) much much more.


........... but 35% bigger "head" is a massive increase in effective head-size.

[pwa]

I "protected" my brain by wearing a helmet on my ride today, and passed quite a few other cyclists (aged from young kids to a bloke probably about 70) all wearing helmets. And guess what! I didn't have an accident of any sort! For the zillionth time I didn't have any sort of incident to put my bonce in danger.

I draw two (possibly conflicting) conclusions from that. Firstly, if wearing a lid is meant to make you take more risks, it isn't noticeably increasing my crash rate. I don't do "pilot error" crashes. Well, not since my teens.

And secondly, I could have had a zillion rides without a helmet and the effect would have been zilch. Make of that what you will.

[Steady rider]

It is rather funny that in about 30 years little research compares the bare head to helmet size and impact rate.

What do the +39% and +89% represent?

Helmeted:- (Sin Q)2 (Sin Q x Cos Q)
Angle Sin Cos Y frontal X sidewards
10 .1736 .9848 .0301 .1709
20 .3420 .9396 .1169 .3213
30 .5000 .8660 .2500 .4300
40 .6427 .7660 .4130 .4923
50 .7660 .6427 .5867 .4923
60 .8660 .5000 .7500 .4330
70 .9396 .3432 .8828 .3213
80 .9848 .1736 .9698 .1709
90 1.0000 .0000 1.0000 .0000
Totals 4.9999 2.8350
Non-helmeted:-
Corresponding impacts for above, angles below 45
degrees would be misses or near misses.
50 – 27.5 .4617 .8870 .2132 .4095
60 – 51 .7771 .6293 .6039 .4890
70 – 65 .9063 .4226 .8213 .3830
80 – 77 .9743 .2249 .9493 .2191
90 – 90 1.0000 .0000 1.0000 .0000
Totals 3.5872 1.5006
They are from the table of relative forces from lines of impact and it appears sideward forces overall would increase, before cushioning effects. 2.835/1.5006 = 1.89

sideward forces causing more brain damage.

[Jdsk]

So when you said:

It is probably the wrong way to view the situation. see Diagram A, most falls are to the side and there would likely be a short time period to move the head away from the expected impact area.

Diagram A didn't actually throw any light on either the distribution of falls or the time period in which the head could be moved away?

Jonathan

PS: Were those trigonometric data from Clarke CF, Bicycle helmets and accident involvement; Cycling World, UK, June 2003? I'd be grateful for help in finding that.