Evaluating the impact of cycle helmet use...

For all discussions about this "lively" subject. All topics that are substantially about helmet usage will be moved here.
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NATURAL ANKLING
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Re: Evaluating the impact of cycle helmet use...

Postby NATURAL ANKLING » 14 Jul 2020, 3:50pm

Hi,
Beaten to a pulp as usual :mrgreen: :lol:
NA Thinks Just End 2 End Return + Bivvy
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Please forgive the poor Grammar I blame it on my mobile and phat thinkers.

Steady rider
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Re: Evaluating the impact of cycle helmet use...

Postby Steady rider » 14 Jul 2020, 7:49pm

In evaluating helmets some of the problems appear to be;
wearing a helmet increases the accident rate
increases the frequency and number of helmet impacts compared to a bare head
helmet impacts generally last longer in duration than for bare head
brain damage is a function of both the level of acceleration and duration of impact
the level of risk varies by cyclist behaviour that may change with helmet usage
Drivers behaviour may change by cyclists wearing helmets
The risk when cycling can change due to several factors
Head injury is related in part to cyclist's behaviour
Many differences have been reported when comparing the behaviour of injured cyclists for wearers and non-wearers.
Helmet legislation when enforced can discourage cycling
When legislation is in force the police can use it to stop selected cyclists if they choose, e.g blacks
Last edited by Steady rider on 14 Jul 2020, 7:52pm, edited 1 time in total.

Jdsk
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Re: Evaluating the impact of cycle helmet use...

Postby Jdsk » 14 Jul 2020, 7:51pm

Some of those are genuine problems that make studies difficult to perform and the results hard to understand.

But some are assertions about what is currently known.

I suggest separating the two.

Jonathan

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Re: Evaluating the impact of cycle helmet use...

Postby Steady rider » 14 Jul 2020, 7:59pm

There is probably some evidence to support all the points made with some being stronger than others.
If you see an 'assertion' perhaps details can be provided to clarify the issue.

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Re: Evaluating the impact of cycle helmet use...

Postby Jdsk » 14 Jul 2020, 8:08pm

A very rough cut:

Problems to be managed in studies:
the level of risk varies by cyclist behaviour that may change with helmet usage
Drivers behaviour may change by cyclists wearing helmets
Head injury is related in part to cyclist's behaviour
Helmet legislation when enforced can discourage cycling

Assertions about what is already known from studies:
wearing a helmet increases the accident rate
increases the frequency and number of helmet impacts compared to a bare head
helmet impacts generally last longer in duration than for bare head
Drivers behaviour may change by cyclists wearing helmets
Head injury is related in part to cyclist's behaviour
Helmet legislation when enforced can discourage cycling
Many differences have been reported when comparing the behaviour of injured cyclists for wearers and non-wearers.

Orphans:
brain damage is a function of both the level of acceleration and duration of impact

Jonathan

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Re: Evaluating the impact of cycle helmet use...

Postby Steady rider » 14 Jul 2020, 8:19pm

More research looking into the level of acceleration/duration of impact for a range of impacts and what could be near misses for a bare head may be useful.

The Case against bicycle helmets and legislation, VeloCity cycling conference, Munich 2007. A detailed report presented at the world’s leading cycling conference providing details showing how helmet use and legislation has reduced both health and safety in general terms. http://www.ta.org.br/site/Banco/7manuai ... helmet.pdf

in addition, extra research considering the accident rate and helmet usage may be good to see.

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RickH
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Re: Evaluating the impact of cycle helmet use...

Postby RickH » 14 Jul 2020, 8:41pm

https://www.cyclehelmets.org/1261.html

Helmet wearing in the Netherlands is estimated at 0.5%

In contrast, 13.3% of cyclists admitted to hospital were wearing helmets (NB that isn't with head injuries that is with any injury). Not because wearing a helmet is hugely dangerous in itself but that they were cycling in a more dangerous manner by nature of the activity they were participating in - 50% of the helmeted admissions were riding MTBs & 46% racing bikes.

These are the sort of confounding factors that make study very difficult. Especially as cycling is a relatively safe activity so the samples to study are small and direct comparison between one place and another can have a multitude of other factors making it even harder to get like for like.

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Re: Evaluating the impact of cycle helmet use...

Postby Jdsk » 14 Jul 2020, 8:53pm

Jdsk wrote:But some are assertions about what is currently known.

The template that we use in systematic reviews in this sort of area is PICO: Population/ Intervention/ Comparator/ Outcome.
https://en.wikipedia.org/wiki/PICO_process

Without something like that it's very hard to synthesise what different studies show.

But of course it's equally useful when designing studies, or describing what you'd like to see in future studies. Because if they're designed with something like that in mind beforehand it's much easier to work out what they mean afterwards.

Jonathan

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Re: Evaluating the impact of cycle helmet use...

Postby Jdsk » 14 Jul 2020, 8:54pm

RickH wrote:Especially as cycling is a relatively safe activity so the samples to study are small and direct comparison between one place and another can have a multitude of other factors making it even harder to get like for like.

Yes.

Jonathan

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Re: Evaluating the impact of cycle helmet use...

Postby mikeymo » 14 Jul 2020, 11:02pm

RickH wrote:Especially as cycling is a relatively safe activity


Relative to what?

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Re: Evaluating the impact of cycle helmet use...

Postby drossall » 14 Jul 2020, 11:39pm

Relative to not-cycling for a start. The medical profession vary widely on how the health benefits stack up, but 20 years of life expectancy gained for every year lost to accidents seems something like an average.

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Re: Evaluating the impact of cycle helmet use...

Postby mikeymo » 14 Jul 2020, 11:41pm

drossall wrote:Relative to not-cycling for a start. The medical profession vary widely on how the health benefits stack up, but 20 years of life expectancy gained for every year lost to accidents seems something like an average.


So I'm going to live 20 years longer because I cycle. Is that what you're saying?

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Re: Evaluating the impact of cycle helmet use...

Postby drossall » 15 Jul 2020, 12:06am

No.

Imagine that you could work out the total number of years of life expectancy that cyclists lose in fatal accidents. For the sake of argument, say that, across all cyclists, we on average live one month less because of accidents. (No idea whether that figure is even remotely true - I plucked it out of the air). But then we'd also live 20 months longer because of health benefits.

Of course it's all about averages, and in reality some people suffer fatal accidents, sometimes quite young, while others live almost forever. But the whole thing is about future expectancy - it's a bit late, when either of those has happened to you, to start wondering whether cycling is a good idea! You can never know for certain that you'll live another 20 years, but cycling would appear to do far more, through health promotion, to help you to do so than it risks through accidents.

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Re: Evaluating the impact of cycle helmet use...

Postby mikeymo » 15 Jul 2020, 12:15am

drossall wrote:No.

Imagine that you could work out the total number of years of life expectancy that cyclists lose in fatal accidents. For the sake of argument, say that, across all cyclists, we on average live one month less because of accidents. (No idea whether that figure is even remotely true - I plucked it out of the air). But then we'd also live 20 months longer because of health benefits.

Of course it's all about averages, and in reality some people suffer fatal accidents, sometimes quite young, while others live almost forever. But the whole thing is about future expectancy - it's a bit late, when either of those has happened to you, to start wondering whether cycling is a good idea! You can never know for certain that you'll live another 20 years, but cycling would appear to do far more, through health promotion, to help you to do so than it risks through accidents.


I see, I understand now, thank you. You should go into statistics or epidemiology or some field like that. I sure hope I'm one of those people who lives "almost forever". Yes, you right, the whole thing is about "future expectancy". Past expectancy is just too late.

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Re: Evaluating the impact of cycle helmet use...

Postby pjclinch » 15 Jul 2020, 8:26am

mikeymo wrote:
RickH wrote:Especially as cycling is a relatively safe activity


Relative to what?


As has been noted, relative to not cycling is one. Rather than look at life expectancy you might look at health at a certain age, and as a regular 50-something cyclist the general estimate is I'll be in similar shape to my 40-something non-cycling notional twin. That gets more and more important the older you get. Doctors are now starting to prescribe cycling because of the health benefits.

Relative to walking, mile for mile the number of serious injuries and fatalities are similar in the UK, cycling comes out slightly better. You do have issues that of course a cyclist might be expected to do more miles, so you can compare hour for hour but you're never quite comparing apples to apples because ultimately different modes are used in different ways. Cycling is less safe than driving by most measures, but not ridiculously so, and it also depends a lot on where/how you cycle. The Doom/Distance ratio for the UK as a whole for cyclists is about 23/billion km IIRC, about double that of NL (12) but if you're on urban back roads the average is 8 (better than NL as a whole!) but if you're on rural A roads it hits a whopping 170 (that may be distorted by the low amount of cycling that happens on rural A roads, but even so it sure ain't good).

There's cycling and there's cycling, of course. If your idea of "cycling" is BMX Supercross it probably isn't that safe, but for a lot of A to B transport on the sort of roads people are happy to cycle on without trying to set PBs cycling just doesn't measure as very dangerous by the standards of everyday things folk do that aren't felt to be "dangerous".

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