Question Is there data to support RF to 4 or not?

Persimmon

Active member
I am so confused and would appreciate it if someone could please explain this to me. I read posts that say that we don't have data regarding RF vs FF past 2 y.o. and that we don't know if RF to 4 is safer but what about the British Medical Journal article that states:

"...One study conducted 31 frontal crash tests with 12 month, 18 month, and 3 year old dummies restrained in both US and European rear facing and forward facing seats.[8] All rear facing seats resulted in significantly lower injury measures for neck and chest compared with the forward facing seats; the European rear facing seats had the lowest injury risk.[8] Another study conducted numerical simulations comparing a 3 year old dummy restrained in both forward facing and rear facing seats.[11] It found that upper neck forces and neck injury criteria could be greatly reduced by using a seat that was rear facing. The conclusion encouraged manufacturers to develop rear facing seats suitable for children up to 4 years of age."

??? It is not US data but US physicians use international data to make medical decisions. The article was published in 2009 so there has been lots of time for peer comment and retraction if the studies mentioned in the article were flawed. :confused:

ETA: Link to study:
http://www.medscape.com/viewarticle/704630
 
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ADS

Persimmon

Active member
Ahhh. OK, thanks so much. Now I get it, sort of.

I asked someone who is an academic medical researcher and practicing physician (MD, PhD) and sits on the Institutional Review Board (they are the ones who review medical studies being conducted at the university) at our local medical school about the British Medical Journal. He said that it is a peer reviewed medical journal which is the gold standard for any academic journal. I asked him if he used data from international peer reviewed medical journals when making medical decisions. He said, "All the time. It would be negligent not to."

It just seems odd to me that it is accepted practice for a physician to use data from an international peer reviewed medical journal to make, at times, life or death decisions about medical care but some techs don't acknowledge it. Is that part of the the tech training--only use US data?
 

bree

Car-Seat.Org Ambassador
Those studies with the 3 year old crash test dummies are North American studies. The British Medical Journal cited them, but they are North American studies; one is from Canada and the other is from the US.

ETA: Actually, I don't know if they referenced the Canadian study. The Sherwood study (Reference #8 ) is a US study, but I'd have to look into reference #11, because I thought they are referencing the Canadian one.

ETA2: The Canadian study I was thinking of was this one: http://carsafetyandkids.ca/user_upl...hree-year-old_hybrid_iii_dummy_1343917391.pdf and it looks like one of the authors is A Howard, so I think he was involved in the study Reference # 11.
 

Persimmon

Active member
Those studies with the 3 year old crash test dummies are North American studies. The British Medical Journal cited them, but they are North American studies; one is from Canada and the other is from the US.

ETA: Actually, I don't know if they referenced the Canadian study. The Sherwood study (Reference #8 ) is a US study, but I'd have to look into reference #11, because I thought they are referencing the Canadian one.

ETA2: The Canadian study I was thinking of was this one: http://carsafetyandkids.ca/user_upl...hree-year-old_hybrid_iii_dummy_1343917391.pdf and it looks like one of the authors is A Howard, so I think he was involved in the study Reference # 11.

So that makes it even more odd to me. They are North American studies. Why wouldn't they be acknowledged by US techs?

For everyone to see, here are the References cited:

[8] Sherwood CP, Crandall JR. Frontal sled tests comparing rear and forward facing child restraints with 1-3 year old dummies. Annu Proc Assoc Adv Automot Med 2007;51:169-80.

[11]Emam A, Sennah K, Howard A, Chapman M. A study of injury parameters for rearward and forward facing 3-year-old child dummy using numerical simulation. International Journal of Crashworthiness 2005;10:211-22.

ETA: This is from the abstract of Reference #11
"In this paper a multi-body dynamic simulation MADYMO model is developed for rearward and forward facing 3-year-old child dummy. The reasonable correlation between the developed forward facing numerical simulation results and the experimental results indicates that the model is robust. Simulation for both facing configurations is conducted using an experimental moderate frontal crash pulse. The study indicates that the upper neck forces, and the neck injury criteria can be greatly reduced by keeping the child in the rearward facing position. For children safety, parents and caregivers should seriously consider keeping children rearward facing for as long as possible. Moreover, manufacturers should be encouraged to develop car safety seats that accommodate children rear facing up to 4 years of age."
 
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thepote

New member
Were there auto manufacturers that were pushing for RF to 4 in the early 2000s and wanting seat manufacturers to catch up to that? What was that conclusion based on?
 

bree

Car-Seat.Org Ambassador
So that makes it even more odd to me. They are North American studies. Why wouldn't they be acknowledged by US techs?

For everyone to see, here are the References cited:

[8] Sherwood CP, Crandall JR. Frontal sled tests comparing rear and forward facing child restraints with 1-3 year old dummies. Annu Proc Assoc Adv Automot Med 2007;51:169-80.

[11]Emam A, Sennah K, Howard A, Chapman M. A study of injury parameters for rearward and forward facing 3-year-old child dummy using numerical simulation. International Journal of Crashworthiness 2005;10:211-22.
Thanks for posting the full references. I'm not really sure why these studies aren't more well known or acknowledged.

Were there auto manufacturers that were pushing for RF to 4 in the early 2000s and wanting seat manufacturers to catch up to that? What was that conclusion based on?


I don't know about any auto manufacturers pushing for rear-facing until 4 in the early 2000s, so I hope someone else will have more info on that, though my US Volvo manual says that kids should rear-face until 4.

In 2002, the American Academy of Pediatrics said that "Manufacturers should be encouraged to develop car safety seats that accommodate children rear facing to 4 years of age (45 lb)." (link: http://pediatrics.aappublications.o...full?sid=161b28ba-8f5b-477f-99c1-899a1444899e). It looks like it is the following study that is cited in the paragraph about rear-facing: ↵ Weber K. Child passenger protection. In: Nahum AM, Melvin JW, eds. Accidental Injury: Biomechanics and Prevention. New York, NY: Springer-Verlag;2002:523– 549
 

Persimmon

Active member
The lead researcher from Reference #8 is at the University of Virginia and the study got funds from the Centers for Disease Control and Prevention so sounds like US.
 

christineka

New member
The big European study that came out several years ago, used data from Sweden and North America. I was under the impression that it was a European study. I read through the whole thing. They compared rear-facing 3 year olds (in Sweden) to 3 year olds in shield boosters in the US. I would like some better data- 3 year olds, properly harnessed forward-facing... Here's the study I know about. http://kidsincars.blogspot.com/2008/06/new-european-research-children-should.html
 
V

VanIsleMommy

Guest
Even though the cars and seats may be different, the laws of physics don't change. A frontal crash results in the child being thrown forward. You can have the tear facing child in a seat which transfers forces to the seat back or you can have the child held in by a harness which transfers the force to the head and neck.

Sent from my iPhone using Car-Seat.Org
 

Persimmon

Active member
I would like some better data- 3 year olds, properly harnessed forward-facing...

The study #8 referenced in the article was conducted using frontal sled tests that included 3 year old dummies in RF and FF harnessed restraints as far as I can tell. Here is a link to the images of the US seats used in the tests. Look for Figure 3 top left and right images. If you click on the title of the image it will give you a pop up of larger images.

http://www.ncbi.nlm.nih.gov/pmc/?term=18184491[PMID]&report=imagesdocsum

Anyone recognize these seats?
 

arly1983

New member
The study #8 referenced in the article was conducted using frontal sled tests that included 3 year old dummies in RF and FF harnessed restraints as far as I can tell. Here is a link to the images of the US seats used in the tests. Look for Figure 3 top left and right images. If you click on the title of the image it will give you a pop up of larger images.

http://www.ncbi.nlm.nih.gov/pmc/?term=18184491[PMID]&report=imagesdocsum

Anyone recognize these seats?

I see a Britax Marathon 65, A graco Cargo in the top row of figure 3
NExt row: not sure about the first one and a MaxiCosi Priori

In figure 1 the first seat looks like a Evenflo Triumph and not sure about the 2nd one.
 

rachelandtyke

Well-known member
The study #8 referenced in the article was conducted using frontal sled tests that included 3 year old dummies in RF and FF harnessed restraints as far as I can tell. Here is a link to the images of the US seats used in the tests. Look for Figure 3 top left and right images. If you click on the title of the image it will give you a pop up of larger images.

http://www.ncbi.nlm.nih.gov/pmc/?term=18184491[PMID]&report=imagesdocsum

Anyone recognize these seats?

In Figure 1, the US seat is an Evenflo (yellow knobs give it away). Maybe an older triumph?

In Figure 3, the left US seat is a Britax Marathon. Not sure about the one on the right, although it reminds me of an old Graco.
 

Brigala

CPST Instructor
The way I understand it, we have crash test data, but no real-world statistics for kids over age 2 rear facing in north america.

A crash test can tell us how much force is applied to a dummy. Statistics tell us how many children are injured, severely injured, or killed. We just don't have enough kids riding rear-facing past age 2 to compile reliable real-world data. The only country where most kids RF past two is Sweden, and they have so many other vehicle safety advances that it's really difficult to weed out how much of their child safety success is due to ERF and how much is due to other factors.

Still, Sweden's success and the crash test data along with some good old-fashioned logical thinking is enough to convince me to rear-face well past age two and as long thereafter as we can manage it.
 

Persimmon

Active member
The way I understand it, we have crash test data, but no real-world statistics for kids over age 2 rear facing in north america.

A crash test can tell us how much force is applied to a dummy. Statistics tell us how many children are injured, severely injured, or killed. We just don't have enough kids riding rear-facing past age 2 to compile reliable real-world data.

Hopefully as more people ERF we will get more real world data. I think these studies are significant enough that I wish more parents were informed of them so they could factor them into their decision on how long to RF.
 

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