How to protect your brain by not wearing a helmet

[pjclinch]

Also the progressive trend to bigger, especially wider cars may have an impact as there's effectively less room for passing things.

[Cyril Haearn]

'Culture' of eating while driving? I thought culture was something good

Just read that vehicles are a few centimetres wider and longer than a few years ago on average. And 159 kg heavier
Equal to permanently carrying two more passengers

[pjclinch]

Fiat 500, then and now...



And the Range Rover...

[Steady rider]

Syd » 23 Jul 2020, 6:59am wrote;

Only one of a number of changing factors in the past 20 years. Here are a couple more.

1. There are an extra 5 to 6 million registered cars in the UK since 2000 further clogging busy roads.
2. As councils are further stretched the quality of road surfaces is declining, again not helped by increasing traffic.

Based on these two alone it would be interesting to see KSI figures showing collisions with other road users vs solo cyclist incidents. Been searching but unable to find any.

Certainly any distraction is serious safety issue. New Zealand data suggests the main problem from helmet use is a higher fall off rate, but other changes can also affect the situation. https://www.researchgate.net/publicatio ... jury_rates

New Zealand
The chart and Table 3 below compare the change in the number of New Zealand public
hospital discharges15 and total hours cycled16 for people aged 5yrs and older. Relative injury
risk is shown for 1989-1990 and subsequent changes are detailed following their helmet law in
1994. The information shows a reduction in average hours cycled per person of between
41.24% and 59.32% and an increased accident/injury risk based on per million hours cycled of
between 34.96% and 121.31%. For 5yo+ public hospital discharges from accidents not
involving a motor vehicle, the risk of injury per million hours cycled increased 107.2%% from
23.38 in 1989-1990 to 35.85 in 1997-1998 to 48.45 in the 2003/07 period.

For New Zealand in five year periods from 1989-93 to 2009-13, the number of cyclist deaths not
involving a motor vehicle increased from 9 to 10, 12, 16 and 29.

[Jdsk]

Certainly any distraction is serious safety issue. New Zealand data suggests the main problem from helmet use is a higher fall off rate, but other changes can also affect the situation. https://www.researchgate.net/publicatio ... jury_rates

I don't consider this a reliable source on the effects of helmets on brain injury.

Let's take those New Zealand data as an example. Clarke's key citation is his own paper:
"Evaluation of New Zealand’s bicycle helmet law"
http://www.cycle-helmets.com/nz-clarke-2012.pdf

Clarke's summary in full in that is:
Summary
The following trends were observed following the introduction of New Zealand’s helmet law:
• Cycling usage reduced by 51%.
• Cyclist’s injury risk per hour increased by 20–32%.
• Estimated to have contributed to 53 premature deaths per year (due to
reluctance to cycle and hence people not exercising).
• Thousands of fines are issued annually for not wearing a helmet.
• May contribute to discrimination in accident compensation and the legal processes.
• Could have contributed to environmental pollution and environmental harm (due to use of vehicles in place of cycles).
• Possibly diminishes civil liberties and human rights (by imposing a requirement to wear a helmet when several reports raise serious doubts whether they improve safety overall).
Is a mandatory cycle helmet requirement the best approach to promoting health and safety for the nation?

But the original data on injuries in New Zealand come from:
Tin Tin et al (2010)
"Injuries to pedal cyclists on New Zealand roads, 1988-2007"
https://bmcpublichealth.biomedcentral.com/articles/10.1186/1471-2458-10-655

Now look at Figure 3, below: "Annual rates of traffic injuries to pedal cyclists that resulted in death or hospital inpatient treatment by body region affected." Total and serious injuries to all parts of the body increased across the three time periods... with one exception... "Traumatic brain injury". In their words:
Our analysis showed the declining trend in rates of traumatic brain injuries from 1988-91 to 1996-99. However, it is unclear whether this reflects the effectiveness of the mandatory all-age cycle helmet law implemented in January 1994 or simply reflects a general decline in all road injuries during that period. On the other hand, we found a steady increase in injuries to other body parts over the twenty year period. However, there is a relative dearth of research focusing on such injuries and potential protective measures such as extremity guards.

Now follow that finding of reduction (and relative reduction) in traumatic brain injury through the two Clarke papers. Or try to... where has it gone? And yet he cites the Tin Tin paper and explicitly says:
Tin Tin et al provided information on the change to ‘upper extremity’ (injuries per million hours cycled) in Figure 3. It increased from 4.4 to 13.20, indicating a 200% higher rate by 2003/07.

Jonathan

[The utility cyclist]

From the circa 1.3Million reported head injuries to hospitals in England and 160,000 hospitals stays from same, it's pretty obvious that riding a bike is safer than many ordinary activities despite the criminals in motors doing their utmost to redress that balance.

That KSIs of cyclists have actually increased significantly since the mid 00s with no increase in journeys (but a few % points in miles travelled) yet pedestrian safety has improved and many other aspects of road safety have been put in place and motorvehicle protection for those outside the vehicle, shows us that something is having a significant detrimental influence.

The only major thing to have happened and affects significant numbers of the journeys/miles travelled are cycle helmets being worn by people on bikes, there's the diversion away from those doing the harm because focus has been pushed virtually every single time to the vulnerable person/s to armour up and at fault for not doing so far too often if they get hurt or worse killed (Michael Mason is a prime example of that).
We know full well what happened in Aus the minute helmets became the focus and the 'war' on speeding motorists ceased, a downward trend of cycle KSIs started to go up, that despite the lowered cycle numbers!

The overall effect of helmets has been an unmitigated disaster and cost hundreds if not thousands of lives, not to mention the discrimination

Only one of a number of changing factors in the past 20 years. Here are a couple more.

1. There are an extra 5 to 6 million registered cars in the UK since 2000 further clogging busy roads.
2. As councils are further stretched the quality of road surfaces is declining, again not helped by increasing traffic.

Based on these two alone it would be interesting to see KSI figures showing collisions with other road users vs solo cyclist incidents. Been searching but unable to find any.

You completely ignored that pedestrian safety has increased significantly over and above that of people on cycles over the same period, they've been subject to the same problems that people on bikes have regards motons/motorvehicles yet have far better outcomes over the same timescale.
There's a huge differential since helmet wearing started to become a big thing and worn virtually as a default in cycling clubs/weekend warriors and then onward to the commuter, potterer/leisure cyclist, tourist and audaxer alike.

[Syd]

From the circa 1.3Million reported head injuries to hospitals in England and 160,000 hospitals stays from same, it's pretty obvious that riding a bike is safer than many ordinary activities despite the criminals in motors doing their utmost to redress that balance.

That KSIs of cyclists have actually increased significantly since the mid 00s with no increase in journeys (but a few % points in miles travelled) yet pedestrian safety has improved and many other aspects of road safety have been put in place and motorvehicle protection for those outside the vehicle, shows us that something is having a significant detrimental influence.

The only major thing to have happened and affects significant numbers of the journeys/miles travelled are cycle helmets being worn by people on bikes, there's the diversion away from those doing the harm because focus has been pushed virtually every single time to the vulnerable person/s to armour up and at fault for not doing so far too often if they get hurt or worse killed (Michael Mason is a prime example of that).
We know full well what happened in Aus the minute helmets became the focus and the 'war' on speeding motorists ceased, a downward trend of cycle KSIs started to go up, that despite the lowered cycle numbers!

The overall effect of helmets has been an unmitigated disaster and cost hundreds if not thousands of lives, not to mention the discrimination

Only one of a number of changing factors in the past 20 years. Here are a couple more.

1. There are an extra 5 to 6 million registered cars in the UK since 2000 further clogging busy roads.
2. As councils are further stretched the quality of road surfaces is declining, again not helped by increasing traffic.

Based on these two alone it would be interesting to see KSI figures showing collisions with other road users vs solo cyclist incidents. Been searching but unable to find any.

You completely ignored that pedestrian safety has increased significantly over and above that of people on cycles over the same period, they've been subject to the same problems that people on bikes have regards motons/motorvehicles yet have far better outcomes over the same timescale.
There's a huge differential since helmet wearing started to become a big thing and worn virtually as a default in cycling clubs/weekend warriors and then onward to the commuter, potterer/leisure cyclist, tourist and audaxer alike.

You have to ask why pedestrian safety appears to have increased significantly.

How do pedestrian numbers in 2020 relate to figures in 2000? Taking it further how does pedestrian time and distance traveled compare? How has road infrastructure changed in the past 20 years that offers no benefits to other road users? e.g underpasses, barriers between pavement and road near junctions etc.

It is easy to fling statements about but without in depth analysis is like comparing apples with budgerigars.

[Icsunonove]

You have to ask why pedestrian safety appears to have increased significantly.

How do pedestrian numbers in 2020 relate to figures in 2000? Taking it further how does pedestrian time and distance traveled compare? How has road infrastructure changed in the past 20 years that offers no benefits to other road users? e.g underpasses, barriers between pavement and road near junctions etc.

It is easy to fling statements about but without in depth analysis is like comparing apples with budgerigars.

The improved safety design standards for vehicles with regard impact with pedestrian probably has helped immensely... also more than likely improved survivability for cyclist too to a certain extent.
https://en.wikipedia.org/wiki/Pedestria ... cle_design
Unfortunately these advances are at risk now due to the growing menace of SUVs.

[Steady rider]

Jdsk » 23 Jul 2020, 1:13pm wrote

Steady rider wrote:
Certainly any distraction is serious safety issue. New Zealand data suggests the main problem from helmet use is a higher fall off rate, but other changes can also affect the situation. https://www.researchgate.net/publicatio ... jury_rates

I don't consider this a reliable source on the effects of helmets on brain injury.

The research is focused on the overall accident rate and helmet use but includes some information on concussions.

Let's take those New Zealand data as an example. Clarke's key citation is his own paper:
"Evaluation of New Zealand’s bicycle helmet law"
http://www.cycle-helmets.com/nz-clarke-2012.pdf

This paper was peer-reviewed and published by the Medical Journal of New Zealand. New Zealand data is only part of the information provided on the increased risk from helmet use and legislation.

The Tin Tin data was not provided by age group but TBI did reduce over the period. Fig 3 shows TBI reducing in total from about 20 to 10. Fig 3 is not complete, missing lower 'lower extremity' for 'Other'.
Upper extremity increased from about 7 to 18 per million hours cycled.

The problem with focusing on the reduction in TBI is that most likely a good proportion were to the younger age group and cycling reduced for the 5-17 age group from 23 million hours per year in 1989/90 to 6 million hours in the 2006/09 period.

Tin Tin was unsure if the reduction in TBI was due to helmet laws. Clarke had no further evidence to suggest the reduction was due to the helmet law, except for reducing cycling levels. Tin tin stated;

Our analysis showed the declining trend in rates of traumatic brain injuries from 1988-91 to 1996-99. However, it is unclear whether this reflects the effectiveness of the mandatory all-age cycle helmet law implemented in January 1994 or simply reflects a general decline in all road injuries during that period. On the other hand, we found a steady increase in injuries to other body parts over the twenty year period. However, there is a relative dearth of research focusing on such injuries and potential protective measures such as extremity guards.

Annual pedestrian deaths reduced from about 90 in the 1989/90 period to about 37 in the 2006/09, down by about 60%.

Clarke reported;

Head injuries—Collins et al8 reported accident data for 1988, ‘Fifty-one percent of
those hospitalised were aged 5–14, and males accounted for 70% of all admissions.
Thirty-four percent involved a collision with a motor vehicle. Intracranial injuries and
skull fractures accounted for 46% of hospital admissions, and had the highest scores
on the abbreviated injury scale (AIS).’ For the age group 5–17 it is possible that this
group account for about 65% of head injury admissions pre law. Estimating a 75%
reduction as per survey information on 65% would mean an estimated 48% reduction
in head injuries. In addition road safety has improved resulting in far fewer deaths,
e.g. 754 deaths in 1989 and 393 in 2006.7

In brief, the example provided trying to show the findings were unreliable provides no proof at all.

[Jdsk]

Clarke was writing about helmets and their effects. He wrote a whole paper on New Zealand. What's your explanation for him not mentioning the New Zealand data on the reduction in traumatic brain injuries, the putative harm that helmets are most likely to reduce? He doesn't mention them, although he cites the original paper and mentions the findings for other body parts... which increased.

That's just one example. Here's a couple more:

The two Clarke papers (above) are from 2012 and 2019. By that time methods for systematic reviews were pretty mature. But he doesn't use them to identify the relevant original data. Have a look at his Methods section: no mention of the criteria used for selecting or rejecting papers. Without that the risk of selection bias is higher than it needs be.

And then at his data. Again take the example of the Tin Tin study (or any other of the original sources). The original study contains hypotheses, significance testing and confidence intervals for findings. These all disappear in Clarke so that there is no attempt to assess whether any observed changes might have occurred by chance alone.

Jonathan

[Jdsk]

The problem with focusing on the reduction in TBI is that most likely a good proportion were to the younger age group and cycling reduced for the 5-17 age group from 24 million hours per year in 1989/90 to 6 million hours in the 2006/09 period.

You can express injuries in lots of ways: absolute, adjusted for hours spent, adjusted distance travelled. One of the properties of comparing injuries to different parts of the body is that it's not affected by those.

But the New Zealand data for traumatic brain injury adjusted for hours travelled are conveniently available, below. (I don't know how to improve the resolution of the image but it looks a bit better if opened in a new window.) The black points in the LH panel are cycling related injuries and in the RH panel are traumatic brain injury per million hours travelled, and the open points in both are estimated helmet wearing rates.

Traumatic brain injury adjusted for hours travelled, the exact measure that you wanted, went down.

The figure is from a response to Clarke's paper:
"Response to ‘Evaluation of New Zealand’s bicycle helmet law’ – letter to the editor"
Wang et al (2014)
https://www.researchgate.net/publication/260252686_Response_to_'Evaluation_of_New_Zealand's_bicycle_helmet_law'_article

Jonathan

[Steady rider]

The display in Fig 1 is misleading. The first graph shows overall injuries, not serious injuries. The rate of serious injuries per million hours cycled reduced from 10.27 - 4.86 - 6.24. The display should have shown serious injuries v TBI and both would have shown similar patterns.

Clarke explains the reduction in children cycling could have a major impact on TBI injury rates. He provides a reference to one article relating directly to head injuries.
https://www.cyclehelmets.org/1237.html

The methods used by various researches will vary and their backgrounds will vary. There can be major weaknesses in some reports.
Weaknesses with a meta-analysis approach to assessing cycle helmets. Feb 2017 http://worldtransportjournal.com/wp-con ... eb-opt.pdf

[Jdsk]

Clarke explains the reduction in children cycling could have a major impact on TBI injury rates.

Please see the data adjusted for hours travelled in the preceding post.

Jonathan

[Jdsk]

The methods used by various researches will vary and their backgrounds will vary. There can be major weaknesses in some reports.
Weaknesses with a meta-analysis approach to assessing cycle helmets. Feb 2017 http://worldtransportjournal.com/wp-con ... eb-opt.pdf

Yes, Clarke again. That one's a conference abstract: has he ever published those "weaknesses" in a substantive paper?

Jonathan

PS: Yes, systematic reviews and meta-analyses have weaknesses, but all other known methods have more. In a review there's no good reason for not stating why some original studies were included and others not. There's also no good reason for not assessing statistical reliability particularly when it was done in the underlying original publications.

[Steady rider]

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

provides the full paper.

Evaluation of Australia's bicycle helmet laws, The Sports Science Summit, O2 venue London UK http://www.cycle-helmets.com/au-assessment-2015.pdf Presented 14 January 2015.

Table 4 shows how the serious injury rate can vary by age group, from 107 for the 9-10 age group to 12 for the 60-64 age group.
Table 3 shows data for Australia, TAC data from accidents involving motor vehicles, 67% of head injuries and concussions were from the 0-17 age group.

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.