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they simply are unable due to science to change events that much
ISTR it's a fine line over which G forces cause serious injury. As you rightly say the helmet slows your brain down, so it's experiencing say 20G instead of 60G, where 60G is the threshold for injury. You gave the right description then the wrong conclusion in your own post.
Erm, the picture of the cracked helmet that shows no signs of compression?
It does to me. Lots of cracks. How did it crack if it didn't compress?
It does to me. Lots of cracks. How did it crack if it didn’t compress?
You can see the EPS is compressed in the pic? Why are you being so tediously personal/pedantic/Big-Hitter? Have I wee'd on your ships recently?
I also broke up an old helmet to have it take up less space in the bin. Or at least, I tried. I stamped the shit out of it and it cracked but didn't smash. And it deformed elastically in the process 🙂
You can see the EPS is compressed in the pic? Why are you being so tediously personal/pedantic/Big-Hitter?
You are talking about plastic compression, right? I'm saying that elastic deformation occurred. You know the difference right?
Have I wee’d on your ships recently?
No, you're talking bollocks, and that's why I'm taking you up on it. It's not personal 🙂
I expect a lot of people don’t how much force it takes to kill someone by a blow to the head (and that it’s way higher).
A Big Hit?
Wow. Said with such confidence.
But no expertise at all to back that level of confidence. This is STW, not a neuroscience convention after all.
Actually as I have read a lot of the literature on helmets, foillowed a lot of the science, understand how they work ( which its clear most folk do not) and understand the mechanisms of brain injury I do have some knowledge on this
Phew! Tough crowd in here this aft 🙂
Get well soon SR.
In this case to say – the helmet saved me from a brain injury would seem about right.
A one that may have killed him.
EDIT damn HTML formatting.
This link has a table about 1/3 of the way down showing injury severity vs G force: http://www.internationalbrain.org/examination-of-bi-thresholds-in-terms-of-the-severity-of-head-motion-and-the-brain-stresses/
If you cna reduce G force by half, you could drastically reduce the severity. And given that a helmet is quite a bit thicker than the brain membrane, I can see that would be entirely plausible. I couldn't find numbers on how much helmets reduce brain G force though.
You are talking about plastic compression, right? I’m saying that elastic deformation occurred. You know the difference right?
I do, yes, in the cirumstances it's obvious what I was talking about and you are just trolling with this.
I'm not the only one querying how a doctor can know whether a helmet saved a life from looking at it, you says his "experience" is enough. No comeback on the other points at all.
a) my wife and children gave me the helmet as a gift, and thought that “daddy would like the stripes”,
Option a) is well cooler.
It’s becoming the post that keeps giving this one 🤣😜
I’m not the only one querying how a doctor can know whether a helmet saved a life from looking at it, you says his “experience” is enough. No comeback on the other points at all.
I'm also not saying he can know for sure. I'm saying he probably can have a reasonable guess. But that's not what I'm calling you out for.
I'm calling you out because you said that the helmet looked as if it did nothing, when I think it's pretty clear it did a lot.
It does piss me off a bit when armchair experts think they know more than those who do this stuff for a living, based on an over-inflated sense of their own intelligence.
Somewhere in Canada, Alanis Morissette just exploded.
Okay, that’s great. But your not the OP?
No, you are correct, I am not the OP.
I wasn't making any comment on the OP's helmet. I was responding to the subsequent anecdote that cracking without obvious deformation is often observed, with my own anecdote about seeing neither crack or deformation after hitting my own helmet hard on the ground, which caused me to ponder how effectively my helmet had mediated the impact of my crash. One of the following posts suggested I had failed to see the crack in the OP's helmet, so I responded to this post to clarify that I was referring to the condition of my own helmet after my accident, and not referring to the condition or efficacy of the OP's helmet.
I hope this explains what I have written, but happy to provide further explanation if I have not clarified things.
Nonsense TINAS, I’m not even going to bother.
Bayesian probability, you're arguing that if every bit of evidence is incorrect then your alternative hypothesis is correct. Which is a valid line of reasoning.However with each extra bit of evidence your hypothesis is less and less likely. Everyone else is arguing that even if SR's account, the smashed helmet and the neurologists opinion are individually fallible and should not be give much weight, collectively they point to the conclusion that SR would have been in worse shape had he not worn a helmet.
I’m not the only one querying how a doctor can know whether a helmet saved a life from looking at it
I’m just guessing here but I’d imagine that the doctor was basing his assessment on his observation of SRs injuries and an assessment of the circumstances under which they were inflicted rather than an examination of the actual helmet?
I have a selection of cracked and broken helmets that I’ve been wearing during crashes over the years. I use them as hanging baskets, a sobering reminder of how many substantial blows to the head I would have had if it wasn’t for wearing them.
No, you are correct, I am not the OP.
So nothing to do with the OP?
Phew! Tough crowd in here this aft.
Nah,it's all show 😉
Ywan
you said that the helmet looked as if it did nothing
No I didn't
Bayesian probability, you’re arguing that if every bit of evidence is incorrect then your alternative hypothesis is correct.
No I'm not.
SR would have been in worse shape had he not worn a helmet.
I've not argued against that either
he doctor was basing his assessment on ... an assessment of the circumstances under which they were inflicted
So he has somehow been able to assess impact speed, angle, surface type, measured the brain deceleration? From looking at the helmet or the evidence "I rode into a wall"?
So he has somehow been able to assess impact speed, angle, surface type, measured the brain deceleration? From looking at the helmet or the evidence “I rode into a wall”?
No, he'd read the notes taken during his the OPs history taking.
Awesome internet experts knowing more than real experts and argue the point is awesome. Might read this thread again just for the awesomeness.
If you would have died without the helmet you would have a serious brain injury with it. As you apparently have no brain injury then the impact force was not enough for a fatal brain injury without the hat
Bravo.
When we all learn the error of our ways and just stop listening to Experts once and for all.
Who needs experts with all their knowledge and years of relevant experience 🙄
“Some bloke on the internet” is always available to point out the obvious truth the so called “experts” always miss.
I honestly suspect that I should not even have <i>begun</i> the descent at the speed I did.
It's a scary descent, even in good conditions. I've had a go at going fast down it a couple of times, still never averaged more than 20mph. It also sucks you in at the top with a steady slope and then the hairpins appear very quickly. If you don't know it and are a confident descender then you can easily go into it way too fast. Easy mistake to make so I wouldn't dwell on it. Just shit luck.
Somewhere in Canada, Alanis Morissette just exploded.
Funny, but you know what? I'm not the one making absolute proclamations. I'm just discussing what we can see. Which is fine. If I were dealing out certainties I'd be just like Al wouldn't I? But I'm not saying the same thing.
So nothing to do with the OP?
What is nothing to do with the OP?
If I were dealing out certainties I’d be just like Al wouldn’t I?
What certainties am I dealing out then?
Um...
Sorry to intrude on all the cock fighting. But if you take a look at pictures 4 and 5 on SRs original post, it's pretty clear permanent deformation has occured. You might need to pinch zoom at touch.
As you were.
Wow. It's like wearing a pair of very familiar but uncomfortable slippers this thread. I'm relieved the OP is on the mend and I agree, you can't dwell on a simple mistake like that. We all make them, normally without any consequence. I'm glad your head is in a better condition that it would have been without a helmet.
Whoever said after a crash, 'Well, at least I wasn't wearing one of those helmets - that could have been much worse'?
No-one, ever.
Yeah I've already checked out of this one.
Hard armour doesn't have to absorb any energy to "work", it can also have an effect by spreading force out so energy is absorbed by a larger amount of body tissue, none of which is subjected to such high forces/pressures/accelerations as a smaller area of tissue would have in the absence of the armour. So in the case of a helmet you get a sore neck but not a cracked skull plus local brain damage. In the case of body armour you get sore ribs but don't get stabbed by pointy sticks or torn by sharp rocks.
Yeah I’ve already checked out of this one.
LOL/raiseeyebrows etc
I struggle with long sentences and I'm sure it's been said above but it doesn't look to me (also from your injuries) that your head/helmet took a great deal of the impact. I expect it helped a bit, but so would cycling a bit more cautiously!
When I did an involuntary header many years ago, the forehead section of the helmet that had directly hit the ground was substantially crushed. I was lightly concussed.
Funny, but you know what? I’m not the one making absolute proclamations. I’m just discussing what we can see. Which is fine. If I were dealing out certainties I’d be just like Al wouldn’t I? But I’m not saying the same thing.
To be fair, it was more of a general comment, than a comment on your contribution to this particular thread, which has been relatively sensible. You do deserve though it, but are far from the only one 😜.
Its very clear that very few of the folk commenting understand how helmets work at all.
As for medical opinion - I suggest you look at the BMJ debates on it. Medical opinion is very divided.
I have read a lot of the data and research on helmets,. Followed the debate in the medical world on it, worked in head injury rehab. Not an appeal to authority but simply stating my position that I have some knowledge
If you cna reduce G force by half, you could drastically reduce the severity. And given that a helmet is quite a bit thicker than the brain membrane, I can see that would be entirely plausible. I couldn’t find numbers on how much helmets reduce brain G force though.
Well, I can't find the data for a human skull with no helmet - but EN1078 requires no more than 250g at 5.50m/s etc - a Leatt downhill helmet smashes this requirement out of the ballpark by more than a 100g in every test.
So if a helmet can smash a standard by 100g, it's going to reduce unprotected Gs by a great deal more.
Got any data for your opinion TJ?
What do you think of this paper?
https://www.ncbi.nlm.nih.gov/pubmed/29677686
Yes lots but I am checking out of this debate as its pointless. People will believe what they want to not what the evidence states. follow the science. follow the evidence. Read it all critically. follow the BMJ debates. Mke your own mind up.
Lets rewind on the helmet debate; prevention is better than cure .. and a cracked helmet (even if it did have world champ stripes on it)
You guys can argue the merits of what protection a helmet provides - or makes you feels it provides, but the actual cause of the accident here was an over estimation of ability ... and a disregard of possible dangers - caused by inexperience of the potential dangers of descending an unknown descent.
More skill may have got you around the bend safely, and greater experience would have encouraged you to have gone down it slower.
Speedy recovery James
Then we have this one, that states that "These results suggest that an adjustment for risk compensation is difficult due to a lack of data and such an adjustment may also be unnecessary"
and also states that helmets are effective in mitigating head injuries.
Whilst Ben Goldacre has essentially stated - in short - that it's too complicated to call either way, right now.
https://www.bmj.com/content/346/bmj.f3817.full?ijkey=I5vHBog6FhaaLzX&keytype=ref
Another
https://www.sciencedirect.com/science/article/abs/pii/S1369847816305666
"Risk compensation is an unlikely effect of using bicycle helmet."
I'm not interested in the helmet debate, I just want to say that your previous thread regarding the accident made me descend a bit slower on Saturday, and rightly so given the conditions.
Get well soon SR.
At the end of the day for whatever reason SR slid headfirst into a wall. Once you've arrived at that point, as far as I'm concerned only an idiot would say a helmet doesn't afford at least some protection. That doesn't mean you should wear one, that always has to be personal choice.
I for one am glad SR was wearing one, considering the helmet damage and his injuries which were sustained by forces originating from a blow to his head, it's very likely that his consultant is correct.
Chin up SR you've been given another bite of the cherry, I know you'll make the most of it.
I’m not interested in the helmet debate
Get well soon SR.
This. Only on STW can some poor bloke lying in pieces descend into an argument about wearing helmets.