FMVSS 213 compliance testing

Thank you both for your responses. DD2 is old enough now to really voice her opinion and she wants to be ff like her sister. This has been going on for a while now and I though she had given up on the argument because on a long trip last month she was ff in her YS and she complained that her legs hurt. So, I told her that her legs wouldn't hurt rf and she went back to her XT.
She loves the GN & YS because I think it makes her feel like a big girl and she feels good about herself when she rides in these seats. At 3.5y/o I'm feeling like she deserves a "voice"...but I know as much as anyone here about the increased safety rf so I will continue to encourage her to rf.
She has head flop in the GN, but sleeps very nicely in the YS. So I guess the YS is the one I'll go with. I'm surprised the Radian didn't get better numbers for head excursion with the safestop

The Safestop INcreases head excursion. The numbers should be lower if it were removed. (The longer it takes you to come to a dead stop, the less your chances of being injured. Throw an egg at a brick wall, it stops REALLY fast and breaks. Throw an egg at foam, the foam makes it slow down over a longer period, and it doesn't break. The safestop is just an extra layer of 'foam' to slow down your stopping time... the seatbelt and harness and the car itself are the major factors, though, so other seats without safestops or rip stitch tethers are also still safe to use).

firemomof3 said:

I'm surprised the Radian didn't get better numbers for head excursion with the safestop

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The SafeStop actually increases head excursion, which is part of why there is a weight limit on it. The SafeStop is designed to limit the load on the neck by allowing the harness to stretch, increasing ride-down time. Because it allows the harness to stretch, it increases head excursion (and possibly knee excursion as well).

firemomof3 said:

So I guess the YS is the one I'll go with. I'm surprised the Radian didn't get better numbers for head excursion with the safestop

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This is something that I've been wondering about, too.

But, someone posted that head excursion is the measurement from the vehicle seatback to the extension of the head of the child, rather than the actual neck elongation. (You may already know this, but I'm not a tech, so I this was news to me. I'm learning new things here every day.).

So, if a Radian's safe stop is an elastic harness part that stretches more to reduce strain on the neck, wouldn't it actually make the head excursion numbers higher than without it? The trade off is that there may be less strain on the neck with the safe stop? If there is plenty of space between the seat in front of the child seat, perhaps a Radian with safe stop and higher extursion numbers is better than a seat with lower excursion numbers?

ETA: I was typing the same time as Jools and Pixels - Thanks!!

Regarding the YS, could you tell me if it has metal bars inside like the Vivo?

Thank you for that explanation reguarding the safestop!! I understand now and it makes sense to me :thumbsup:
Metal bars? I just went out and looked at the YS and I don't see any

firemomof3 said:

Thank you both for your responses. DD2 is old enough now to really voice her opinion and she wants to be ff like her sister. This has been going on for a while now and I though she had given up on the argument because on a long trip last month she was ff in her YS and she complained that her legs hurt. So, I told her that her legs wouldn't hurt rf and she went back to her XT.

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Ah ha, that would be the difference then, your child has a FF to look at! My oldest is in a seat belt only, so although the little one jokes that she's going to sit like her sister, she understands that seat belts are for "big people only" and the only car seats she sees is RF.

joolsplus3 said:

I'd choose the one that installs best and is easiest to use properly every time. Seems like too simple of an answer, I know, but it's really the truth. I'd also probably choose the one that her head doesn't flop when sleeping. If her head is dangling forward of the wings then the seat is offering a lot less side impact protection should you get T-boned. :twocents:

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Agreed. These tests are pass/fail tests for compliance. They are not intended for safety comparisons and the results are probably close to meaningless in that regard. Other factors like fit to vehicle, fit to child and ease of use are more important for models that pass the compliance testing. Until the NHTSA develops a program with testing specifically designed to allow parents to compare the crash safety of child seats, discussions like this are purely theoretical with little practical application.

In a general sense, though, I think head excursion numbers are likely to prove to be the most important.

so in thinking about the safestop and similar type features that are meant to increase head excursion and ride down time, it makes me think that we are off in thinking that the smallest HE numbers are automatically the best. I mean, it seems like maybe somewhere in the middle is the place to shoot for? Unless you have a tiny backseat, then maybe the smallest #s. Or a huge backseat, then maybe the largest numbers. Does this make sense? Do you think this could be widely applicable?

But here again, another reason why testing on a sled bench is very very far from telling us what happens in real life. soooooo much depends on the car and the space the child is surrounded by.

romanoma said:

so in thinking about the safestop and similar type features that are meant to increase head excursion and ride down time, it makes me think that we are off in thinking that the smallest HE numbers are automatically the best. I mean, it seems like maybe somewhere in the middle is the place to shoot for? Unless you have a tiny backseat, then maybe the smallest #s. Or a huge backseat, then maybe the largest numbers. Does this make sense? Do you think this could be widely applicable?

But here again, another reason why testing on a sled bench is very very far from telling us what happens in real life. soooooo much depends on the car and the space the child is surrounded by.

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Well, on that note, I think you are getting into the "FFharness vs. booster" debate. When you talk about ride down time, you're talking about crash forces. In a harness, you have all the force of the forward movement essentially on the neck itself, since the body/shoulders are held back by the harness. In a booster, while it might "look" worse in a crash test, having the one side of the body fly forward and letting some of the non-neck parts of the body, - the back, the length of the spine, shoulder, arm, etc absorb and dissipate some of that force might actually be a safer option than restraining the torso and letting all the force act upon the neck as the head is the only unrestrained body part.
I know we fixate of FF harnessing, even extended harnessing, and harp upon the importance of being "mature" and not wiggling, etc before moving into a booster, etc, but right now, I'm not sure we have enough data to support that? I think we all know that Sweden seems to feel like they have enough data to support the earlier boostering side. so.....that's why it comes down to parental choice, i guess.

But if a kid wiggles out of the seat belt, they would still be safer in a harness. whole torso excursion would be much much less safe. I think I have just heard people here say that they have to be mature enough to sit properly in a seatbelt, not that they have to be 7yo (or some other magic number). If they can stay in the seatbelt, that is a safe option. That's what I have gotten from c-s.org.

But your point about a properly used booster vs harnessed seat is a good one, one that needs more testing. I think most parents are worried that their kid might be wiggling out of the seatbelt at just the wrong moment, making that a much less safe option. There is great peace of mind with a harness if the kid is not 100% reliable in a booster.

Ok, I have owned only Britax seats. My twins were born in 2003 and had outgrown their infant seats by 7mths. The Marathon was the best option for us at the time and served us well. Now we have two Regents....My boys are 6yrs/43lbs/49in tall. When they outgrew their Marathons by height they were not yet 40lbs. We looked at the GN and FN and did side-by-side comparisons but neither fit my boys broad shoulders like the Regent. We got the regent and love it. It is an easy install in every car I have put it in and get solid installs. My twins are comfy and sleep well w/out heads flopping forward like they would have in the GN b/c it sat way too upright when placed in our car plus the crotch strap was under them and didn't fit properly.

Now that all said...and by looking at these numbers I am still pleased with our purchase as it fit my boys best and still fits them great. Also, the 2008 data file (previous year) they tested the Regent with a 6yr old, w/lower anchors and w/TA and it had nice head excursion results. All the tests done in 2009 were not tested w/lower anchors and some w/out TAs. This repeats the TC tests as seats used with lower anchors and TAs did much better overall. I hope this testing will lead to some modifications in lower anchor improvement and hopefully car manufacturers will increase the weight limits for these lower anchors, which would decrease Head Excursion in most seats.

Also, the Boosters in these current tests were also tested w/ seat belts only and in the TC testing some boosters did poorly b/c of the lower anchor use. But as a novice user, if I bought a booster and it had latch you can bet I would use it and make sure it was rock solid which could cause problems for my child based on current crash test results..which again is real life vs sled example.

To conclude...unfortunately, these tests are ran on an outdated sled in a non-typical environment. Like others said the TC testing to me is more impressive b/c seeing real-life crashes with the seats in use makes more sense. The Regent did fine in the TC tests and w/my current set up of TAs and Lower anchor config...I am pretty confident in my Regents and even in our other car w/seat belt and TA I am still fine and feel my boys are safe in their regent.

Based on these results and the results of the TC testing I am tempted to keep them on the lower anchors and just add the seat belt when they are too heavy for our lower anchors. To me this makes sense that it should cause better protection; also if the lower anchor and TA combo reduce head excursion by 300 then why would I not do this? Yes, I know this is not advised but in my opinion and in recent light of these results it should be....but I will make that decision when the time comes....for now we are 5lbs under the weight limit which based on our weight gain could be 2 more years before we face this and we will have outgrown the Regent in height before then since we only have one slot left.

Thanks for the great discussion....Please review the previous year regent testing and let me know if my thinking is correct regarding the Regent.
Jen


Here are the results from 2008 that I am referring to (Line 85):

.............................................. TA LA HIC Ch HE KE
84 Regent, Model E9L3969 6 Yr. Old N N 779 54 744 836 N/A P
85 Regent, Model E9L3969 6 Yr. Old Y Y 751 50 467 749 N/A P
86 Regent, Model E9L3969 3 Yr. Old N Y 730 48 632 728 N/A P

vermontmoms said:

...Based on these results and the results of the TC testing I am tempted to keep them on the lower anchors and just add the seat belt when they are too heavy for our lower anchors. To me this makes sense that it should cause better protection; also if the lower anchor and TA combo reduce head excursion by 300 then why would I not do this? Yes, I know this is not advised but in my opinion and in recent light of these results it should be....but I will make that decision when the time comes....for now we are 5lbs under the weight limit which based on our weight gain could be 2 more years before we face this and we will have outgrown the Regent in height before then since we only have one slot left...

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I just want to clarify. Are you wondering whether or not you should use LATCH and the seatbelt to install your Regents?

bree said:

I just want to clarify. Are you wondering whether or not you should use LATCH and the seatbelt to install your Regents?

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No, I know you only use one or the other...but what I was saying if by using the lower anchor and tether the reduction of HE is 300 compared to seatbelt and TA then this is something worth discussing and pushing for car manufacturers to increase weight loads on the lower anchors.

Also, I am saying that if the reduction of HE is 300 for LA and TA then adding the seatbelt in addition should by theory (and what was also shown by the TC test) add more stability to high weight harnessing seats and offer more protection for a higher weight child. I know this is not approved by any carseat manufacturers BUT it is something to think about and something that will hopefully be tested more down the road. If you think about it is like adding a 5pt harness to your carseats b/c you have two connectors for the lower anchor and two areas where the seatbelt is routed plus the TA, thus you have 5pts of contact to disperse the force in a crash vs 3 points.

Just something to think about not necessarily practice before testing is done.
Jen

Something that carseat manufacturers should consider, if they haven't done so already, yes, I agree.

Here's my problem with looking at TC videos and saying that A looks better than B: All we have are the videos. We don't have any of the dummy instrumentation numbers. So while it might look better to us to see lower anchors and seatbelt together, it might be increasing the forces on the dummy's brain (measured as HIC, Head Injury Criterion) or increasing chest crush (measured as chest deflection). The videos might look pretty good, but without information about what the dummies experienced, it might be worse.

Pixels said:

Here's my problem with looking at TC videos and saying that A looks better than B: All we have are the videos. We don't have any of the dummy instrumentation numbers. So while it might look better to us to see lower anchors and seatbelt together, it might be increasing the forces on the dummy's brain (measured as HIC, Head Injury Criterion) or increasing chest crush (measured as chest deflection). The videos might look pretty good, but without information about what the dummies experienced, it might be worse.

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Wait, I thought that TC did provide info that showed that seatbelt and LATCH together seemed to improve outcomes of the dummy's numbers. Am I remembering incorrectly and the data wasn't provided? I'd go search their site but I'm at work so I actually should go...uh...you know....work...ha! I can search later this evening if no one else has time today.

Pixels said:

Something that carseat manufacturers should consider, if they haven't done so already, yes, I agree.

Here's my problem with looking at TC videos and saying that A looks better than B: All we have are the videos. We don't have any of the dummy instrumentation numbers. So while it might look better to us to see lower anchors and seatbelt together, it might be increasing the forces on the dummy's brain (measured as HIC, Head Injury Criterion) or increasing chest crush (measured as chest deflection). The videos might look pretty good, but without information about what the dummies experienced, it might be worse.

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The TC tests also did injury force comparisons as well and concluded that using both didn't significantly impact injury forces. However, it did keep the childseat in position better than just using one method and reduced forces to the lower anchors and TAs. Which means to me it reduced the likelihood that a child would strike the seat infront of the ff carseat b/c the distance btwn the seats was not compromised as much by stretching or movement of the child's carseat and it also reduced the likelihood of failure of the attachment points (ie. seatbelt/TA/LA). This information is very important for carseat companies and could provide better protection by advising parents to use both methods when possible, especially for higher weight children.

To me this makes sense...children in harness seats do better in a 5pt vs a 3pt b/c forces are dispersed so why would the actual carseats be different. Each attachment site would have less force placed on them if there were more attachment points. This goes back to the racecar driver theory too and why their 5pt harness work so much more efficiently.

Here is the link that describes this part of their research (scroll down toward the bottom) http://www.tc.gc.ca/eng/roadsafety/safedrivers-childsafety-programs-testing-harness-report-923.htm

I knew that TC had the numbers internally, but they weren't released to us. Here is what they said about doubling up: "Overall, installing a child seat with both the UAS and the seat belt did not have a noticeable effect on either the injury measures or how far forward the child seats moved."

vermontmoms said:

Also, I am saying that if the reduction of HE is 300 for LA and TA then adding the seatbelt in addition should by theory (and what was also shown by the TC test) add more stability to high weight harnessing seats and offer more protection for a higher weight child.

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In some few cases, adding the seatbelt to LA did reduce forward excursion. Overall there was no difference.

TechnoGranola said:

Wait, I thought that TC did provide info that showed that seatbelt and LATCH together seemed to improve outcomes of the dummy's numbers.

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Using both together didn't improve the numbers; there was no noticeable difference.

Pixels said:

Using both together didn't improve the numbers; there was no noticeable difference.

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I guess my real point was that I thought they DID provide information on the results rather than us just subjectively guessing results from the videos. So we actually had more info that just the videos, correct?

TechnoGranola said:

I guess my real point was that I thought they DID provide information on the results rather than us just subjectively guessing results from the videos. So we actually had more info that just the videos, correct?

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They did, in summary form. I didn't see it before.

Pixels said:

I knew that TC had the numbers internally, but they weren't released to us. Here is what they said about doubling up: "Overall, installing a child seat with both the UAS and the seat belt did not have a noticeable effect on either the injury measures or how far forward the child seats moved."


In some few cases, adding the seatbelt to LA did reduce forward excursion. Overall there was no difference.


Using both together didn't improve the numbers; there was no noticeable difference.

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Eventhough, the difference was not noticeable (or significant) it would be interesting to see them in graph form with the other two approved methods b/c any reduction even if small is worthy of mentioning. Also, if some seats had significant reduction that is worth noting b/c children in those seats would benefit.

Statistically by combining all seats in this sample makes the reduction effects smaller b/c it averages them and thus makes it harder to see significant effects. Couple that with a small sample size (12) it is almost impossible to get significant results. The differences would have needed to be inches apart to get significance with a sample of 12. To conclude even a small reduction is worthy in my opinion and this setup should definitely be tested further especially since injury forces were not greater by using this double combination.