Crash and helmet

For all discussions about this "lively" subject. All topics that are substantially about helmet usage will be moved here.
Steady rider
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Re: Crash and helmet

Post by Steady rider »

https://tomt.skillsforaction.com/tomt/s ... -fall-well
This shows children learn how not to hit their heads when falling. The same learning process, avoiding head impact if possible probably applies to cyclists.
https://www.thesun.co.uk/sport/15789425 ... ic-boxing/
But a study by the Global Sport Institute concluded that boxers who competed without headgear were less likely to concussions than those who wore them.

As the study was conducted solely on men, the headgear was dropped for them at the 2016 Games in Rio.

But with no conclusive data yet through for women, head protection has therefore been retained for the women's boxing in Tokyo to ensure maximum safety.
Why should boxers without head gear have a lower concussion rate? Perhaps fewer blows hitting the bare head together with a shorter duration of acceleration to the brain when blows occur.
https://www.researchgate.net/publicatio ... _warranted
Robinson (1996) refers to the Wasserman data that details the incidence of cyclists hittingtheir head/helmet during an 18-month period was “significantly higher for helmet wearers(8/40 vs 13/476 - i.e. 20% vs 2.7%, p 0.00001)." A bare head width of approximately150mm may avoid contact compared to a helmeted head at approximately 200mm wide(Clarke 2007). Assuming the 20% and 2.7% figures are typical, the increased risk of impact for helmeted is about seven times higher. A degree of protection could be expected plus a degree of risk from the extra impacts.
(5) (PDF) Is cycle helmet promotion warranted?. Available from: https://www.researchgate.net/publicatio ... _warranted [accessed Sep 13 2022].

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5647505/
The authors indicated that impacts resulting in a linear head acceleration of 70 to 75 was sufficient to result in concussion, although the mean linear acceleration of their data was 98g.
The current results highlight that time between impacts, not just impact magnitude, influences risk for concussion.
tim-b
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Re: Crash and helmet

Post by tim-b »

Squirrel!

"So if you want to wear a helmet, go ahead, whatever makes you feel safer but I won’t be letting the debate get sidetracked from the things that evidence shows really keep people safe and saves the most lives." Chris Boardman
~~~~¯\(ツ)/¯~~~~
AlaninWales
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Re: Crash and helmet

Post by AlaninWales »

Steady rider wrote: 13 Sep 2022, 7:54pm
Why should boxers without head gear have a lower concussion rate? Perhaps fewer blows hitting the bare head together with a shorter duration of acceleration to the brain when blows occur.
https://www.researchgate.net/publicatio ... _warranted
Other factors include:
- Risk compensation: It's far easier to ignore blows to the head when they 'just' shake your head around and don't bruise and split the skin, so some boxers have a tendency to pile in whilst letting the headgear soak up the blows (and some use the gloves for the same thing, holding them in contact with the head). The 'protection' offered by the helmet (which protects the skin but not what is within) just seems like enough.
- Blows to the head are allowed to continue for longer than would happen in a bare-knuckle, bare-headed contest. Without padding, knuckles split skin and bleeding happens sooner. This leads to (usually) earlier intervention and rapid bleeing from the eyebrows means a boxer is unable to continue, without the shaking the brain otherwise would get.
- A bare head is not only smaller, but (paricularly if shaven) sleeker. Ducking and weaving is facilitated and blows are more difficult to land without glancing off.
rmurphy195
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Re: Crash and helmet

Post by rmurphy195 »

Tiggertoo wrote: 12 Aug 2022, 9:56pm I crashed last Friday - wheels went out from under me on a tight/wet curve - and banged up my knee, arm and thigh (all mendable), but for the first time crashing - I have done it a few times (mostly by dogs) my head hit the pavement hard and set my head pounding.

The reason I am posting this thread is that my helmet broke along the side receiving the blow. If I had not been wearing the helmet, I would not be here today to write this. I am not going to preach, but I cannot imagine for one second riding without a helmet and I wouldn't allow anyone to ride with me who did not wear one.
Oh dear, that was asking for it wasn't it! By cracking/disintegrating or whatever the "helmet" in this case absorbed some of the energy from the impact. I've seen much the same thing when a rider went into a wrought-iron gate - helmet hit one of the upright spars and cracked, but the riders head didn't!

If you look closely at modern car bumpers many are made in much the same way as our bonedomes (a plastic skin of some sort over an expanded foam lump) for exactly that reason.
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pjclinch
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Re: Crash and helmet

Post by pjclinch »

rmurphy195 wrote: 15 Sep 2022, 6:08pm
Oh dear, that was asking for it wasn't it! By cracking/disintegrating or whatever the "helmet" in this case absorbed some of the energy from the impact. I've seen much the same thing when a rider went into a wrought-iron gate - helmet hit one of the upright spars and cracked, but the riders head didn't!
It takes a lot more to crack a skull than a helmet.
My sister's a primary school teacher, on a trip once one of the kids tripped and fell and stopped by taking it on the head against a wrought iron fencepost. Looking at the wound they could see the bone. The skull remained intact though and although it was a hospital job the child was ultimately okay.

People really ought to stop assuming that a cracked bit of expanded polystyrene is clear evidence that they've been saved a fractured skull.

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Rabbit
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Re: Crash and helmet

Post by Rabbit »

On the cracked skull thing, my mother in law (78) slipped and fell on the marble floor of her Tenerife apartment, falling backwards onto a step. She hit it with such force with the back of her head that a big chunk of the marble flooring broke off and although she was out cold for a few minutes and spent a couple of days in hospital for tests there was no fracture of the skull. Of course, it could be she's just got a very thick head, but even so...
mattheus
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Re: Crash and helmet

Post by mattheus »

tim-b wrote: 12 Sep 2022, 6:00am
Millions of years of evolution.
That isn't evidence. Millions of years of evolution would tell cyclists that an icy bend is dangerous, but they ignored it that day in Lelystad
Ha ha! You think the human species has millions of years of experience cycling around ice??
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horizon
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Re: Crash and helmet

Post by horizon »

saudidave wrote: 21 Aug 2022, 7:45pm
Since then the number of irrespnsible d******ds driving cars has increased exponentially
The number of people driving cars (at all levels of competence and care) has indeed increased enormously over the past 50 years. But my own and perhaps personal experience of this is that more traffic equals greater safety both for cars and bikes. The roads I fear most are sparsely populated with traffic, have higher speeds and lower levels of concentration. Give me a traffic jam on a narrow road any day!
When the pestilence strikes from the East, go far and breathe the cold air deeply. Ignore the sage, stay not indoors. Ho Ri Zon 12th Century Chinese philosopher
mattheus
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Re: Crash and helmet

Post by mattheus »

rmurphy195 wrote: 15 Sep 2022, 6:08pm ... the "helmet" in this case absorbed some of the energy from the impact. I've seen much the same thing when a rider went into a wrought-iron gate - helmet hit one of the upright spars and cracked, but the riders head didn't!
I see a LOT of pictures of cracked helmets - so remember this is barely absorbing any energy at all. Think of car CRUMPLE zones - they are not made out of brittle materials, deliberately!
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pjclinch
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Re: Crash and helmet

Post by pjclinch »

horizon wrote: 21 Sep 2022, 11:37am
saudidave wrote: 21 Aug 2022, 7:45pm
Since then the number of irrespnsible d******ds driving cars has increased exponentially
The number of people driving cars (at all levels of competence and care) has indeed increased enormously over the past 50 years. But my own and perhaps personal experience of this is that more traffic equals greater safety both for cars and bikes. The roads I fear most are sparsely populated with traffic, have higher speeds and lower levels of concentration. Give me a traffic jam on a narrow road any day!
Look at a breakdown of doom/distance ratios by road type and the ones that are far more likely to get you dead using them are rural main roads. Deaths per billion km average is about ~24 in the UK (quoting from memory, but that's the right ballpark) as a whole, and about 170 for rural main roads. Urban back roads at 8, safer than the Dutch national average at ~ 12!

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dmrcycle
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Re: Crash and helmet

Post by dmrcycle »

pjclinch wrote: 16 Sep 2022, 10:38am
rmurphy195 wrote: 15 Sep 2022, 6:08pm
Oh dear, that was asking for it wasn't it! By cracking/disintegrating or whatever the "helmet" in this case absorbed some of the energy from the impact. I've seen much the same thing when a rider went into a wrought-iron gate - helmet hit one of the upright spars and cracked, but the riders head didn't!
It takes a lot more to crack a skull than a helmet.
My sister's a primary school teacher, on a trip once one of the kids tripped and fell and stopped by taking it on the head against a wrought iron fencepost. Looking at the wound they could see the bone. The skull remained intact though and although it was a hospital job the child was ultimately okay.

People really ought to stop assuming that a cracked bit of expanded polystyrene is clear evidence that they've been saved a fractured skull.

Pete.
Its not skull fracture thats the issue its brain trauma. A fractured skull is not a problem but a bleed on the brain is and thats just luck if you hit your head
dmrcycle
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Re: Crash and helmet

Post by dmrcycle »

mattheus wrote: 21 Sep 2022, 1:17pm
rmurphy195 wrote: 15 Sep 2022, 6:08pm ... the "helmet" in this case absorbed some of the energy from the impact. I've seen much the same thing when a rider went into a wrought-iron gate - helmet hit one of the upright spars and cracked, but the riders head didn't!
I see a LOT of pictures of cracked helmets - so remember this is barely absorbing any energy at all. Think of car CRUMPLE zones - they are not made out of brittle materials, deliberately!
Not true, crumple zones are to decelerate gradually and plus its hard to make a steel car shatter. A cracked helmet is absorbing energy (and a significant amount to cause fracture in plastic and polystyrene). Its the basic physics of energy.
tim-b
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Re: Crash and helmet

Post by tim-b »

Ha ha! You think the human species has millions of years of experience cycling around ice??
Had you read to the bottom of the same page you'd have read this, "Humans have been traversing ice for millions of years, in the same way that they've been falling out of trees"
So they might know a thing or two about about accelerating, decelerating, changing direction and excessive speed on ice.

And this bit,
"So if you want to wear a helmet, go ahead, whatever makes you feel safer but I won’t be letting the debate get sidetracked from the things that evidence shows really keep people safe and saves the most lives." Chris Boardman speaking about more important issues than whether we should wear a helmet
~~~~¯\(ツ)/¯~~~~
mattheus
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Re: Crash and helmet

Post by mattheus »

dmrcycle wrote: 22 Sep 2022, 12:38am
mattheus wrote: 21 Sep 2022, 1:17pm
rmurphy195 wrote: 15 Sep 2022, 6:08pm ... the "helmet" in this case absorbed some of the energy from the impact. I've seen much the same thing when a rider went into a wrought-iron gate - helmet hit one of the upright spars and cracked, but the riders head didn't!
I see a LOT of pictures of cracked helmets - so remember this is barely absorbing any energy at all. Think of car CRUMPLE zones - they are not made out of brittle materials, deliberately!
Not true, crumple zones are to decelerate gradually and plus its hard to make a steel car shatter. A cracked helmet is absorbing energy (and a significant amount to cause fracture in plastic and polystyrene). Its the basic physics of energy.
... which you don't seem to understand. Quite common in these discussions, please don't feel bad.

I'll try to put this simply; if you crack a protective helmet, it has not reduced* the decelerations involved. It is not crumpling. A thick cushion would be better protection. In fact thick cushions would be good protection for your head against blunt trauma, even though I haven't seen any tests for me to quote at you :)

*Or perhaps only negligibly!
mattheus
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Re: Crash and helmet

Post by mattheus »

tim-b wrote: 22 Sep 2022, 5:57am
Ha ha! You think the human species has millions of years of experience cycling around ice??
Had you read to the bottom of the same page you'd have read this, "Humans have been traversing ice for millions of years, in the same way that they've been falling out of trees"
So they might know a thing or two about about accelerating, decelerating, changing direction and excessive speed on ice.

And this bit,
"So if you want to wear a helmet, go ahead, whatever makes you feel safer but I won’t be letting the debate get sidetracked from the things that evidence shows really keep people safe and saves the most lives." Chris Boardman speaking about more important issues than whether we should wear a helmet
Well I agree with your bold quote (in fact I read it when he first published, a few years ago now I think?). So that's good!

(Let's gloss over the absolute twaddle you've written about evolution and cycling skills ...)
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