Evaluating the impact of cycle helmet use...

This sub-forum all discussions about this "lively" subject. All topics that are substantially about helmets will be moved here, if not placed here correctly in the first place.

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

Postby Vorpal » 20 Sep 2019, 1:15pm

This one is a little more interesting than the last, although it still has many of the same problems. Of particular interest to me was:
There was a statistically significant increase in chest, spinal, upper and lower limb injury in the helmeted group in comparison to the un-helmeted group (all p<0.001), though in a subsequent analysis of these anatomical injury patterns, those cyclists wearing helmets were still found to have lower rates of TBI.


I don't think that their explanation is entirely adequate.
Although previous studies have suggested variations in car driver behaviour towards helmeted and unhelmeted cyclists that may influence the biomechanics of any subsequent collision. it seems unlikely that cycle helmet wearing fundamentally alters the mechanics and injury burden of distant body regions. A plausible explanation
for this significant difference between the helmet and non helmet wearing groups lies in the threshold to inclusion in the TARN Database.
Consequently, an intervention’s success in eliminating one isolated body region injury from the database will result in a relative overrepresentation of all other injury types in that intervention group when compared a control group.

While I can accept that their explanation accounts for some of the difference, they have dismissed the possibility that cyclist or motorist behaviour can influence this without considering possible differences in speed, which have been demonstrated to have a significant effect on injury outcome.
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Wanlock Dod
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Re: Evaluating the impact of cycle helmet use...

Postby Wanlock Dod » 20 Sep 2019, 1:35pm

I can see that not wearing a helmet could potentially result in a lower threshold for inclusion in the study (once a crash has occurred), and wonder whether that should be treated as a confounding factor. I suppose that it would be a fairly common issue for these kinds of studies but don’t recall it ever getting any discussion.

I agree that over looking the possibility of risk compensation on the part of both drivers and cyclists is probably a serious limitation, but they never even considered any of the circumstances of the incidents (due to limitations of the dataset). The authors are clearly only interested in the hazard assessment and seem to have no interest in either risk or the safety of cyclists.

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

Postby RickH » 20 Sep 2019, 4:49pm

I'm reading this on my phone on a train so not easy to study things in detail.

Are the subjects all road incidents or does it include mountain bikers piling into solid objects - trees, rocks, etc, hence the increase in other injuries?

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

Postby Wanlock Dod » 20 Sep 2019, 6:47pm

RickH wrote:Are the subjects all road incidents or does it include mountain bikers piling into solid objects - trees, rocks, etc?

Yes, all of the above were considered to be fair game for this study.

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

Postby Steady rider » 23 Sep 2019, 2:11pm

http://worldtransportjournal.com/wp-con ... 4.4opt.pdf
see Table 12 for reported differences between helmeted and non-helmeted in the USA
The BMJ report details for alcohol 2% v 15%.
It appears other factors could be involved.

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

Postby Vorpal » 24 Jan 2020, 8:54pm

There is recent interesting response to this article on the bmjopen site

Claims of cycle helmet benefit: Selection bias has a stronger claim as explanatory factor.
https://bmjopen.bmj.com/content/9/9/e02 ... ory-factor
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Re: Evaluating the impact of cycle helmet use...

Postby Marcus Aurelius » 24 Jan 2020, 9:03pm

As per usual, nothing is made of consequential escalation. For example, a helmet less rider, is hit in the head, by an object, whilst riding. Loses control, due to being stunned, goes under a truck, the death is attributed to multiple injuries, no one looks at what started the chain of events, because of the ending. Same happens if a helmet less rider falls off, and their head hits the deck, they spin much further into the road, than they would have done, if they’d remained relatively responsive, wearing a lid, they get hit by a vehicle, that wouldn’t have hit them if they’d not gone so far into the road, again the death is put down to multiple injuries, which a helmet wouldn’t have helped with, without looking at the start of the event chain. Helmets save lives, end of, get over it.
Last edited by Marcus Aurelius on 24 Jan 2020, 9:08pm, edited 1 time in total.

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

Postby Mike Sales » 24 Jan 2020, 9:07pm

Marcus Aurelius wrote:As per usual, nothing is made of consequential escalation. For example, a helmet less rider, is hit in the head, by an object, whilst riding. Loses control, due to being stunned, goes under a truck, the death is attributed to multiple injuries, no one looks at what started the chain of events, because of the ending. Helmets save lives, end of, get over it.


Why then do population level studies show no benefits?
Your certainty in the face of the evidence is not shared by better qualified analysts. Get over that.

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

Postby Marcus Aurelius » 24 Jan 2020, 9:13pm

Mike Sales wrote:
Marcus Aurelius wrote:As per usual, nothing is made of consequential escalation. For example, a helmet less rider, is hit in the head, by an object, whilst riding. Loses control, due to being stunned, goes under a truck, the death is attributed to multiple injuries, no one looks at what started the chain of events, because of the ending. Helmets save lives, end of, get over it.


Why then do population level studies show no benefits?
Your certainty in the face of the evidence is not shared by better qualified analysts. Get over that.


As I said, it’s selective viewing and reporting. They rarely look at the whole chain of events, therefore the important first event, is often overlooked / missed, because the bit that causes the biggest problem ( getting hit and killed / seriously injured by a large vehicle, for example ) couldn’t be helped by a lid, but the initial reason for the event chain could / almost certainly would have been helped by doing so.

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

Postby Vorpal » 24 Jan 2020, 9:14pm

Marcus Aurelius wrote:As per usual, nothing is made of consequential escalation.

The study which started this thread doesn't even sort simple falls from motor vehicle crashes, let alone a multi-failure sequence of events such as you described.
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Re: Evaluating the impact of cycle helmet use...

Postby Mike Sales » 24 Jan 2020, 9:24pm

Marcus Aurelius wrote:As I said, it’s selective viewing and reporting. They rarely look at the whole chain of events, therefore the important first event, is often overlooked / missed, because the bit that causes the biggest problem ( getting hit and killed / seriously injured by a large vehicle, for example ) couldn’t be helped by a lid, but the initial reason for the event chain could / almost certainly would have been helped by doing so.


You need a fairly elaborate hypothetical chain of events to maintain your convictions.
You seem to be referring only to the study above.
I was referring to the comprehensive survey of all the available evidence which concluded that no helmet benefit could be shown.
You have been a member of this forum for long enough to have come across mention of Goldacre and Spiegelhalter.
Here is a link to refresh your memory.

https://www.bmj.com/content/346/bmj.f3817.full?ijkey=I5vHBog6FhaaLzX&keytype=ref

Ben Goldacre, Wellcome research fellow in epidemiology1, David Spiegelhalter, Winton professor for the public understanding of risk2


The enduring popularity of helmets as a proposed major intervention for increased road safety may therefore lie not with their direct benefits—which seem too modest to capture compared with other strategies—but more with the cultural, psychological, and political aspects of popular debate around risk.


You illustrate this well.
I strongly recommend reading the whole editorial. It discusses the problems of various types of study, and the emotional responses to the subject.

Note, they conclude that any benefit of helmets is too modest to capture. If they save lives, how is we cannot tell?

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

Postby tatanab » 25 Jan 2020, 7:26am

Marcus Aurelius wrote:As per usual, nothing is made of consequential escalation. For example, a helmet less rider, is hit in the head, by an object, whilst riding. Loses control, due to being stunned, goes under a truck, the death is attributed to multiple injuries, no one looks at what started the chain of events, because of the ending.

Alternatively - a helmeted rider faints due to the heat stress of riding with insulating material on their head. Loses control etc ------ nobody looks at the cause.

Yes, I've see (and experienced) heat stress when using a helmet - even a modern one.

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

Postby fastpedaller » 25 Jan 2020, 2:57pm

tatanab wrote:
Marcus Aurelius wrote:As per usual, nothing is made of consequential escalation. For example, a helmet less rider, is hit in the head, by an object, whilst riding. Loses control, due to being stunned, goes under a truck, the death is attributed to multiple injuries, no one looks at what started the chain of events, because of the ending.

Alternatively - a helmeted rider faints due to the heat stress of riding with insulating material on their head. Loses control etc ------ nobody looks at the cause.

Yes, I've see (and experienced) heat stress when using a helmet - even a modern one.


A young (17 yo) lad in our club many years ago was continually telling me I should wear a helmet whilst time trialling (strangely he thought it unimportant in general group rides) . His Dad bought him one, and during his first 10 mile time trial the lad flung it off as he was boiling up. To my knowledge he never wore it again.

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

Postby The utility cyclist » 27 Jan 2020, 2:44pm

Marcus Aurelius wrote:As per usual, nothing is made of consequential escalation. For example, a helmet less rider, is hit in the head, by an object, whilst riding. Loses control, due to being stunned, goes under a truck, the death is attributed to multiple injuries, no one looks at what started the chain of events, because of the ending. Same happens if a helmet less rider falls off, and their head hits the deck, they spin much further into the road, than they would have done, if they’d remained relatively responsive, wearing a lid, they get hit by a vehicle, that wouldn’t have hit them if they’d not gone so far into the road, again the death is put down to multiple injuries, which a helmet wouldn’t have helped with, without looking at the start of the event chain. Helmets save lives, end of, get over it.

You've no proof of that, we already know that in best case scenario in a lab (the strongest part being the top most section which is not the most frequent conbtact point by far) a helmet cannot reduce the forces that would be the difference between life and death, and the consequences of wearing which increase the likelihood of hitting your head whether that be due to extra risk taking or kinetic energy of the added weight or one of the higher up factors, increasing the size of your head, hugely outweigh any benefit in impacts.
If helmets save lives why do cyclists in pro racing get killed more often compared to pre helmet regulations?
If helmets are supposedly life savers how come not a single country with regards to cycling, nor any sport show there is a direct benefit of helmet wearing?
Pedestrian safety increases far more than cycling safety despite huge increases in helmet wearing or legislation to force wearing to very high % and in the meantime focus is diverted away from the root cause of the vast majority of the KSIs. This diversion is part of the cyclical problem that helmets have created and are the main part of and we know the outcomes from that, we know that despite all the cheerleading cycling in the UK has been stagnant for 15 years, even Netherlands cycling has not increase, Germany has fewer cyclists than it did 10 years ago (with increased car sales over the downward trend of cycling which coincided with e-bike sales increases). Focus on the vulnerable/victims to armour up means less on those actually doing the harm, this means less safety for the vulnerable such that people give up entirely, I read this on various forums and social media frequently. It means an even further inequity of rights, discrimination, even the law itself is being applied in a totally different way due to cycle helmets, such that even someone being mowed down by a hit and run driver is blamed for their death by police and the killer get off and a jury barely consider the actions of the killer but totally on what the victim wasn't wearing :twisted:

And people like you say helmets save lives, end of, no, they cause more loss of life and more injuries amongst so many other wrongs. As I've said before, cycle helmets are the worst thing to happen to cycling since the motor car could go over 10mph!