CUK dropping the ball with MTB advice

[mattheus]

The conclusions were also that the chin (which is unprotected) is the main cause of concussion and the whole principle of boxing is to move your head rapidly to avoid blows.

What happened to :
"any protection is a good idea."

[Stevek76]

What I don’t agree is that there seems to be cherry picked evidence that helmets not only don’t help with road safety (which I could be persuaded that the effect is small overall) but actually they make road safety worse. I just can’t see that in the evidence or in just common sense. I don’t see any significant statistical evidence that there is a negative effect.

Is 'road safety' in this context meaning the effect:

a) on an individual, given the event of a crash
b) on an individual more generally
c) of promotion as a public health measure
d) of mandation as a public health measure

?

[pjclinch]

Pete. I think we are on the same page and good that you are getting a response from CUK. I think the problem is they just used the term off road rather than what they really meant was rough trail MTB riding.

Quoting from the article:

There are five broad disciplines: cross country, trail riding, all mountain (sometimes called enduro), downhill and freeride.

Very briefly, cross country (or XC) involves riding on a mix of rough forest paths, singletrack, doubletrack, fire roads and even paved paths connecting other trails.

Trail riding uses mountain trails, fire roads, logging roads and other unpaved trails.

So with the quite specific inclusion of what they call "trail riding" not conforming to your description of their description I don't agree.

I think the evidence is present that if your hurtling down a trail risk balance means a helmet is a good idea.

It's a reasonable assumption, but that's not the same as "the evidence is present". If it's present please do point us to it. There's very little evidence on MTB safety directly connected to specific MTB trails that I've seen, but TBH I've not looked hard. There's far more on alpine downhill skiing, which has embraced a helmet culture and for which there is evidence that safety-wise nothing much has changed. Aside from helmets we also have similar kit improvements, with the better control afforded by stiffer boots and carving skis that encourage people to go faster down more difficult terrain rather than stick to what they did before in more safety. Again we get back to why we're doing it in the first place and the degree to which people see safety gear as a risk management device rather than a safety gain.

What I don’t agree is that there seems to be cherry picked evidence that helmets not only don’t help with road safety (which I could be persuaded that the effect is small overall) but actually they make road safety worse.

What I don't agree with is that that has any relevance to this thread.

I just can’t see that in the evidence or in just common sense. I don’t see any significant statistical evidence that there is a negative effect.

Not relevant here, and the overall level of argument you'll find from me is that helmet efficacy in terms of significant safety gains against serious injury mainly boils down to "not proven"

To me the helmet is part of my clothing and actually keeps the sun and wind off my head and also protection if I have a knock.

Been there, thought that, told other people that. Now I am increasingly convinced my "always a helmet era" was defined by culture leading me to what I did and then me rationalising that in to "science" and "common sense" placeholders. That's not necessarily a bad thing, by the way: people do what other people around them do, and if that makes you happier riding then go for it. However, had you grown up in NL exactly the same reasoning should apply but you'd almost certainly just do what the other people around you do (i.e., not bother with a helmet) and be happy about that.

We hear stories of people falling and dying as they hit their head on a pavement we all try to protect the one of the most important organs to our life.

We also hear about that from trips and falls though, so why the focus on it happening in cycling falls? Because in the UK the culture is cycling = dangerous while in NL cycling = normal. If falls on to pavement from a bike were a real issue beyond trips and falls the Dutch would have far more to gain than we would as so many more of them cycle in the exact situations a cycle helmet is actually specced for, but they don't bother, and if you lived there it wouldn't be long before you didn't either.
Look back at that advertising copy I posted for the Thudguard Infant Safety Helmet for "learning to walk in a world of hard surfaces" and tell me why you don't buy in to that, but think it applies perfectly to a similar but slightly older kid on a bike? Culture: we know tiddlers fall over but we know after a few hundred thousand years that they typically survive. We used to think that about falling off a bike, but we've now persuaded ourselves that was wrong with no evidence beyond anecdote-driven Fear, Uncertainty and Doubt.

I can’t see that balance or a bigger head being a reason to not wear a helmet as being statistically significant.

I think the balance thing is a red herring because in only stating mechanical forces that completely ignores our conscious and unconscious adjustment for changing circumstances. People will have their balance on a bike changed by e.g. wearing a rucksack or carrying panniers, but it's factored in to their riding (by making the riding harder they are more careful). And look at Danny McAskill etc. and it's pretty clear one can potentially do seriously daft balance-critical things in a helmet. So making an issue of balance strikes me as looking very hard for problems that even if they do exist, are much smaller than other problems we routinely take in our stride and nobody is worrying about.

I think you've missed the boat on a bigger head. It's a simple response to "but extra protection must make you safer, it's just common sense". A bigger head gives two easy (dare I say it, common sense) reasons that's not so. It's easier to hit something bigger, so it'll make the difference between being hit and not in some cases, and it provides more leverage in some situations that can add to injury more than the protection reduces it (the neck is an obvious case in point, with at least one study suggesting significantly more neck injury... but as that study will be prey to the same case/control confounders as I use to wave away a lot of other work I'm not going to dwell on it or tell you you're far more likely to break your neck).
So a bigger head is a potential problem, but of course a potential problem doesn't mean it outweighs other benefits. It does give you a purely mechanical mechanism for helmets to not be completely positive, however.

I spent over a decade convinced it was obviously better to wear one than not, I did a lot of detailed reading around the turn of the century and decided it's actually up in the air, nothing I've seen since has persuaded to me to change my stance further. And the more I look at cultural and psychological effects on behaviour the more I remain convinced it's actually up in the air. That's not a basis to say you ought to wear one or shouldn't think about going off-road without one.

Pete.

[dmrcycle]

I was talking about impacts to the head and it’s effects, not about helmets and protection. Football was an example where the effects of head impacts are seen years later. You mentioned boxing in terms of head protection compaired it to cycling. You don’t seem to be able to form a rational argument.

[pjclinch]

What I don’t agree is that there seems to be cherry picked evidence that helmets not only don’t help with road safety (which I could be persuaded that the effect is small overall) but actually they make road safety worse. I just can’t see that in the evidence or in just common sense. I don’t see any significant statistical evidence that there is a negative effect.

Is 'road safety' in this context meaning the effect:

a) on an individual, given the event of a crash
b) on an individual more generally
c) of promotion as a public health measure
d) of mandation as a public health measure

?

And while we're at it, at what level?
In other words, do we count e.g. road rash as a safety issue, or is that too trivial to bother with? What level of event is the dividing line separating a mere "excrement occurs" incident from one where "safety" is felt to be affected?

This matters. You can have something like track mitts which can reduce pain and injury in a fall but have no real bearing on "road safety". Also you can have things which affect perceived safety like a close pass which have no bearing on injury, but create a tangible negative effect (perception of danger is a leading cause cause of folk not cycling in survey after survey). And so on.

One of the take-aways from "the helmet debate" is, to borrow Goldacre's book title, "I think you'll find its a bit more complicated than that"

Pete.

[Steady rider]

It looks like extra research may be helpful. There is the 1986 short paper with the high acceleration rates on hitting deep pot holes. Today it may be feasible to assess both the level of acceleration affecting the head and assess the extent to which balance may be affected.

There is the issue of when cyclists fall or are knocked off or impact something, how does the rate of head/helmet impact vary for wearers v non-wearers. The 1988 paper by Wasserman provides some data.

Elvik R, et al. (2009) The Handbook of Road Safety Measures, p594, Table 4,10.3
http://www.cycle-helmets.com/elvik-helmets-handbook.pdf
best estimate from mandatory wearing of helmets was 14% increase accident risk per km cycled

Risk of helmet impacts and extra falls
Robinson (1996) refers to the Wasserman data that details the incidence of cyclists hitting their 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 approximately 150mm 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.

For MTB I think a better understanding of these issues is needed before recommending helmets.

[dmrcycle]

Elvik R, et al. (2009) The Handbook of Road Safety Measures, p594, Table 4,10.3
http://www.cycle-helmets.com/elvik-helmets-handbook.pdf
best estimate from mandatory wearing of helmets was 14% increase accident risk per km cycled
.

You can look at data several ways. That data shows a 22% reduction in head injuries. Pretty significant I would say. It also indicates a 14% increase in other injuries. How do we know that’s connected to helmet wearing though. You could argue that despite a 14% increase in overall accidents (due to any cause like traffic density) the head injuries were still even lower with helmet wearing. Or perhaps like with Covid death stats when being admitted there is only one cause. So those 14% would have had head trauma but because the helmet protected them the main reason put on their medical form was limb injury. The other thing to consider is is better to have a head injury or a limb injury. I know which one I would choose.

[mjr]

The wider context comes into play here, in that cycle helmet wearing is widespread, normal even, so an employer could get caned by the newspapers if a very rare event did occur, “Father of two dead because boss refused to buy £50 helmet!”, that sort of thing.

So how do we make cycle helmets seen widely as more like those evil UK electrical socket "protectors", as something which seems at first like a good idea (stop toddlers putting things in the sockets) but in reality increases the injury risk (take the "protector" out and reinsert it upside down into the top hole, it will bend a bit and perfectly open the sprung shutters on the live holes)?

[pjclinch]

The other thing to consider is is better to have a head injury or a limb injury. I know which one I would choose.

Then you haven't thought it through and got enough information, as is so often the case.
If I cut myself shaving that's a head injury. Is that really worse than, say, a broken femur?

These things tend to be reliant on context.

Pete.

[Steady rider]

Table 4.10.3: Table 4.10.3: Effects on injuries of mandatory wearing of bicycle helmets

These figure may not be accurate, but assuming 100 injuries before helmet effects, assume 15 head injuries (data varies quite a bit).
after effects on injuries of mandatory wearing of bicycle helmets, with a 14% increase in injuries and a 25% reduction in head injuries.

injuries 114,
head would have been 15 but increase to 17.1 (15 x 1.14 = 17.1), minus assumed benefit from helmets, 0.25 x 17.1 = 4.25
in total perhaps 114 injuries with 12.8 head.

so the accident rate would increase.
http://www.cycle-helmets.com/zealand_helmets.html provides info for NZ showing an increased risk of 134%

[dmrcycle]

Table 4.10.3: Table 4.10.3: Effects on injuries of mandatory wearing of bicycle helmets

These figure may not be accurate, but assuming 100 injuries before helmet effects, assume 15 head injuries (data varies quite a bit).
after effects on injuries of mandatory wearing of bicycle helmets, with a 14% increase in injuries and a 25% reduction in head injuries.

injuries 114,
head would have been 15 but increase to 17.1 (15 x 1.14 = 17.1), minus assumed benefit from helmets, 0.25 x 17.1 = 4.25
in total perhaps 114 injuries with 12.8 head.

so the accident rate would increase.
http://www.cycle-helmets.com/zealand_helmets.html provides info for NZ showing an increased risk of 134%

Surely the head reduction is from 15 to 11.25 head not 12.8? There is a 25% reduction from the previous year (the 25% is from the previous years figure not a reduction after the increase). All injuries increase by 14% so 114 injuries of which 11.25 are head and 102.75 are not head. Before the law head injuries are 15% of total injuries and after the law change 11.25/114 x100 = 9.86%.

A drop from 15% to 9.86%.

[Steady rider]

Yes that may be the case. My assumption was if injuries increase by 14%, more accidents must occur, and I allowed for an increase before reducing head injuries by 25%.

In numbers prior, 100, 85 plus 15 head
in my suggestion, 114, including 12.4 head, 101.6 not head

your suggestion, 114 injuries including 11.25 head and 102.75 are not head.

Head would reduce by 3 - 4 and other injuries increase by about 16 to 18
The proportion of head injuries reducing from 15% to 9.86% or 10.8% (12.4/114= 10.8%)

The NZ data indicates the increase in the accident rate is much higher than the 14%.

[pjclinch]

<snip>
The NZ data indicates the increase in the accident rate is much higher than the 14%.

But it's not necessarily a fair shout to conflate what happened across a population to the risk of an individual (especially an individual somewhere else without that law in effect), because the law would likely have effects that change the rate beyond the scope of individual riders. For example, changing the demographic mix of overall ridership towards a greater prevalence of sport riders, who tend to have more/more serious crashes. For another example, reducing total ridership could affect the "Safety in Numbers" effect. And so on.

Pete.

[dmrcycle]

<snip>
The NZ data indicates the increase in the accident rate is much higher than the 14%.

But it's not necessarily a fair shout to conflate what happened across a population to the risk of an individual (especially an individual somewhere else without that law in effect), because the law would likely have effects that change the rate beyond the scope of individual riders. For example, changing the demographic mix of overall ridership towards a greater prevalence of sport riders, who tend to have more/more serious crashes. For another example, reducing total ridership could affect the "Safety in Numbers" effect. And so on.

Pete.

Sadly I’m not so sure anymore about the “safety in numbers” effect. I actually think in country of self entitled motorists more cyclists actually make motorists more angry and frustrated and are more likely to do something stupid. I heard on the radio that one in four drivers admitt to a deliberate close pass and a majority want cyclists banned from roads (according to a survey) driven by an increase in cycling during and post pandemic. It’s all on BBC Panorama tonight. Should be an interesting watch.

I think we all agree that changing drivers attitudes and improving ability to share a road with a cyclist would have a much higher effect than helmets. Problem is attitudes seem to be going the wrong way.

[pjclinch]

Sadly I’m not so sure anymore about the “safety in numbers” effect. I actually think in country of self entitled motorists more cyclists actually make motorists more angry and frustrated and are more likely to do something stupid. I heard on the radio that one in four drivers admitt to a deliberate close pass and a majority want cyclists banned from roads (according to a survey) driven by an increase in cycling during and post pandemic. It’s all on BBC Panorama tonight. Should be an interesting watch.

I brought up safety in numbers as a possible way a helmet law might change things rather than as a firm promise about its presence in the UK, but... The above is worry and anecdata. The bigger picture is it appears to work and that's not because e.g. Dutch drivers are saints, but because they're used to bikes in the day to day getting about so account for them. The very odd bampot aside, nobody much wants to run people down because it's messy, time consuming and puts the premiums up even before you get to the human factors. Let's face it, if a quarter of drivers wanted us dead, we'd be dead.

EDIT: I've just seen where you got the "stats" from. @peterwalker99's comments on Twitter regarding these as follows...

The weirdest bit is some statistics, which the BBC also used to promote the show, as newsy top lines, eg 33% of driver think “cyclists shouldn’t be on the road at all.", and 54% think they should have registration plates. Apart, again, from divisiveness, the stats.... seem odd.

These stats, the press release & programme say, come from an "online survey of 12,500 motorists" done by Yonder, who seem to be a consultancy, not a polling firm. A proper poll? My v strong guess is not, but calls to the BBC, Yonder and AA (who co-run the survey) gave no answers.

So unless I'm told otherwise, it seems Panorama felt the need to bulk out the show with some fairly hair-raising and divisive non-statistics based on.... an open-ended online poll supposedly giving the views of "motorists". Really? That's pretty weak stuff.

End EDIT

I think we all agree that changing drivers attitudes and improving ability to share a road with a cyclist would have a much higher effect than helmets. Problem is attitudes seem to be going the wrong way.

That depends where you look. If you look in Angry Places like website comment sections and social media you'd quite possibly think that, but that's not a representative view. Similarly you could judge from those sources that modal filtering is widely perceived to be the work of the devil, but when people get to actually vote for councillors it's more often than not the candidates that oppose it and promise to rip it out that find themselves short of votes.

My own personal feeling (and I appreciate attitudes will change with geography, time/route of travel etc.) is I get noticed more and treated better as time goes on. Maybe the degree to which I'm not generally in a hurry and wear normal clothes for most riding contributes to that, but if so it'd be very hard to quantify.

Pete.