How to protect your brain by not wearing a helmet

[Jdsk]

Weaknesses with a meta-analysis approach to assessing cycle helmets. Feb 2017 http://worldtransportjournal.com/wp-con ... eb-opt.pdf

provides the full paper.

Thanks

Jonathan

[Jdsk]

The NZ situation may have been similar and a major reduction in cycling for children could have resulted in a much lower overall TBI rate.

If the TBI data by age group had been readily available a fuller analysis could have been provided. The 2012 NZ paper used fatality data that is probably more reliable than TBI data.

The data per hour travelled are posted above.

Any explanation for the observed reduction in TBI when injuries to all other body parts increased?

And I'd be interested in why you think that Clarke chose not to refer to that while citing the original study that showed it and explicitly mentioning injuries to another body part.

Jonathan

[Steady rider]

Any explanation for the observed reduction in TBI when injuries to all other body parts increased?
see

https://www.researchgate.net/publicatio ... jury_rates
Table for arm injuries
NZ cyclist data is now available for motor vehicles and other crashes, in general since the helmet laws motor vehicles/cyclist crashes have not increased, bearing in mind cycling to work data. 'other' - falls mainly have increased.

And I'd be interested in why you think that Clarke chose not to refer to that while citing the original study that showed it and explicitly mentioning injuries to another body part.

Data by age group was not readily available and Tin Tin et al mentioned an increased accident rate.

The rate of traumatic brain injuries fell from 1988-91 to 1996-99; however, injuries to other body parts increased steadily.

With a major reduction in children cycling, a reduced TBI was expected, however Tin Tin details other body parts increased steadily.

Clarke speaking about helmet laws https://www.youtube.com/watch?v=5dJ64o9 ... e=youtu.be

[Jdsk]

With a major reduction in children cycling, a reduced TBI was expected...

Isn't that adjusted by the hours travelled, the specific metric that you asked for?

... Tin Tin details other body parts increased steadily.

Yes, injuries to all other body parts went up, but to the brain went down. Why do you think that difference occurred?

Jonathan

[Steady rider]

Table 1 in the 2019 paper shows data from falls v MV accidents, skull fractures 9% from falls v 21% from MV accidents.

Helmet use increases the accident rate from falls, see Discussion and NZ information. Rate increased from 23 to 69 per million hours.

[Jdsk]

Should I conclude that you're not going to answer the question about TBIs going down while injuries to other body parts went up (whether you adjust for hours travelled or not)?

Thanks

Jonathan

[Steady rider]

The answer appears to be due to the changes in the ratio of adults to children plus the change in the higher proportion of accidents due to falls and potential changes due to improved road safety.

Total hours cycled would reduce and with children having higher head injury rates than adults, head injuries would reduce by a larger percent.
With helmet use resulting in a higher fall off rate this would increase the rate of other body parts injured. Helmet use may also help prevent some head injuries. The combination of factors seems to be a lower head injury rate and increased other injury rate per million hours cycled.

[Jdsk]

The answer appears to be due to the changes in the ratio of adults to children plus the change in the higher proportion of accidents due to falls and potential changes due to improved road safety.

Total hours cycled would reduce and with children having higher head injury rates than adults, head injuries would reduce by a larger percent.
With helmet use resulting in a higher fall off rate this would increase the rate of other body parts injured. Helmet use may also help prevent some head injuries. The combination of factors seems to be a lower head injury rate and increased other injury rate per million hours cycled.

Thanks.

Are there any data to support that explanation? Obviously that would be the age specific rates of injuries to body parts and the rates of falls causing injuries compared others causes.

And any reason to reject the rather simpler possibility that it might be due to brains being protected by helmets more than other body parts?

Jonathan

PS: Any guesses why Clarke doesn't mention the finding at all despite citing the paper that shows the reduction in TBI?

[Steady rider]

Looking at information from Australia and providing very rough calculations to illustrate how the rate of TBI may change.
http://www.cycle-helmets.com/au-assessment-2015.pdf

Referring to Tables 3 and 4, Table 3 accidents involving motor vehicles roughly shows head and concussions to be 12% for the 0-17 age range v 7.6% for 18+age group

Table 4 shows the serious injury rates per 10 million km. This can roughly be related to hours cycled. It reports;

Roughly, the 9-16 age group had a rate of 55 and the 17-64 age group a rate of 20 and for age 65+ a
rate of 110 per 10 million km. Indications are that the 65+ group comprised about 1% of distance cycled, the
0-16 age group about 60%, and the 17- 64 age group about 39%.

Assuming TBI is related to serious accidents and in proportion to TAC data, Table 3 data, serious injury and proportion of head/concussion by age group, (not actual NZ data for TBI but using NZ data for hours cycled)
55 x .12 v 20 x 0.076 – 6.6 v 1.52
Hours cycled for NZ in Table 4 https://www.researchgate.net/publicatio ... jury_rates
23 million for the 5-17 age range v 16 million for 18+ range in 1989/90 ,
23 x 6.6 v 16 x 1.52 – 152 v 24 – total 176 from 39 million hours, 4.5 per million hrs
for the 2006/09 period, roughly 6 million hrs for the 5-17 age group v 17 million for 18+
6 x 6.6 v 17 x 1.52 – 39 v 26 – total 65 from 23 million hours, 2.82 per million hrs
This would equate to a 37% reduction in the rate of TBI due to the change in the proportion cycling.

In addition road safety improved, motorcyclists had 51% reduction in the rate of serious injuries by 2003/07.

Clarke looked at the overall trends in fatalities and other issues, all the data from Tin Tin et al was already known and Tin Tin was unsure what the reduction in TBI was due to. if a follow up evaluation of the NZ helmet law was produced I think it would try to include more detailed information on head and TBI data.

All the general findings of the Clarke paper seem valid and more recent research shows the damage that has resulted from the helmet law and helmet use.

ps
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3242550/

and https://www.researchgate.net/publicatio ... w'_article
http://www.nzma.org.nz/journal/read-the ... -1402/6298

Reply to Wang et al response to ‘Evaluation of New Zealand’s bicycle helmet law’ article
12th September 2014, Volume 127 Number 1402
https://www.tandfonline.com/doi/abs/10. ... ode=ibjn20

[OldLimey]

I have no interest in all the technical jargon because it gets confusing, and some folks seem able to prove anything with figures. I sometimes wear a helmet but only when I go on 20 - 30 mile runs during the winter months. It's too hot in Florida (I'm a Brit living here) to be doing long runs so I ride four miles in the early morning and another four as the sun about disappears. I don't wear a helmet on the short runs.

I rely more on my riding skills than I do personal protection. I know crashes can happen, and I've been over the handlebars when I hit someone's homemade speed bump in the dark. I had no helmet on but I instinctively put my hands out. I landed on my chest and my head didn't touch the road.

When I was 18 I had a head-on motorcycle crash with a Mod (I was a Rocker). A friend on a motorcycle behind me told me how I flew through the air and landed on my head. My helmet was crushed on top like a breakfast egg. That would have been my skull. So that convinced me to wear a helmet. Despite that, I rode a motorcycle for many years in the US, and even belonged to a group that fights mandatory helmet laws. I think it's dumb to not wear one on a motorcycle. But I don't see it the same way on a bicycle. Most deaths on bicycles around here are due to cyclists doing stupid things in traffic. My many years of riding a motorcycle have helped me be a better cyclist, putting to use all that I learned in experienced motorcycle riding courses. How many cyclists get proper training?

I'm fortunate in that I can ride on the sidewalks (pavements) all over our county, so I'm not mingling with traffic. And it's a rare thing to see a pedestrian on the sidewalks. Six years of riding a bike (since I retired) and not one crash apart from hitting that illegal speed bump in the dark. So I don't consider it a must to wear a helmet. Would I mandate wearing a helmet? Not at all.

[OldLimey]

If not wearing a helmet protects our brains, why do pro racing cyclists wear them?

[NATURAL ANKLING]

Hi,
Who shot JR

[RickH]

If not wearing a helmet protects our brains, why do pro racing cyclists wear them?

Because they have to!

It is the rules.

But it doesn't mean the rules are necessarily right (or wrong). There are rules in racing covering all sorts of things.

[Steady rider]

https://globalsportmatters.com/health/2 ... wear-them/

[Jdsk]

That's an important study, and the authors include:
"The most convincing hypothesis is that head guards give a false sense of safety and so boxers partake in more high-risk behaviors than they would have done were they not wearing a head guard."

But they don't provide any evidence for that risk compensation, and the study they cite (Hagel et al 2004) doesn't include boxing in the activities considered. (It does include cycling.)

This needs more research.

Jonathan

https://journals.lww.com/cjsportsmed/fulltext/2017/01000/Use_of_Head_Guards_in_AIBA_Boxing_Tournaments_A.13.aspx#R8-13
https://journals.lww.com/cjsportsmed/Fulltext/2004/07000/Risk_Compensation__A__Side_Effect__of_Sport_Injury.1.aspx