Kyle Miller Foundation... misinformed, me or them?

ADS

skipspin

New member
The instructions on the Radians (at least the new ones) say that it can be used with the shoulders abouve the slots as long as the ears aren't over the top of the seat. (Paraphrased)

AFAIK, there is nothing like that in the Regent manual.

So, they are half-right.
 

waterbaby

New member
Okay, good to know.

What would you (general you... CPST "you") consider best practice? If a parent asked you if that was okay (to use FF if the shoulders were above the top slots)?
 

CRS

Senior Community Member
If the CR manufacturer stated the seat could be used above the top slots and a parent asked me if it was ok, I would say Yes, it is ok.
 

safeinthecar

Moderator - CPS Technician
Only the Radian 80 allows shoulders over the slot. The main reason we avoid shoulders over is because it allows additional head excurrsion. In very young children there is also some risk of spinal compression. By the time children are around 4-5 this risk is significantly lower. It is highly unlikely that a child under this age will have shoulders taller than the 18 inch top slots of the Radian, so the main concern becomes head excursion. The Radian 80 has been tested, and found to be safe to use with shoulders over the top. This may seem odd to most parents and techs, but this is hardly the first seat that allows it. In fact, may special needs seat allow it.

Kimberly
 

Victorious4

Senior Community Member
Any manufacturer that says it's OK to use when shoulders are above the top slots are basing that on using the 10 year old sized crash test dummy -- this is all fine & dandy for the dummy ... but, the dummy doesn't have a real spinal chord: until we really know the risk of SPINAL COMPRESSION there's just no way I'm risking it on my own kid or any kid at a seatcheck unless there is absolutely no other possible safer solution :twocents: (a properly used booster would be safer, but if a booster cannot be used properly, then I'd shoot for a vest)
 

safeinthecar

Moderator - CPS Technician
There are many many factors that have contributed to SK allowing the top slots below the shoulders. Since questions regarding these factors are causing so much controversy on the boards, I thought I'd share some of the info I have.

The first issue I would like to address is the idea that measuring the spinal compression is not possible because we have no dummies that test for it. This is not correct.

SID II(s), which stands for Side-Impact Dummy, version two, small, is representative of a 5th-percentile female. Like her Hybrid III sister, she is also 5 feet tall and weighs 110 pounds. This dummy is a derivative of the original SID, a 50th-percentile male dummy that was developed in the late 1970s by NHTSA. Because humans who are in a side-impact-type of collision are likely to suffer different types of injuries than those in a front-end collision, side-impact dummies have ribs and a spine that flexes differently in a crash. They are built specifically so that researchers can measure the risk of injury to the ribs, spine and internal organs, such as the liver and spleen.

SID II(s) was built as a special project by a group of researchers working with a group of automakers. Currently, she is only being used in the side-impact testing conducted by the IIHS, although NHTSA is considering a proposal to put her into use in its program. The IIHS began using her in its early developmental side-impact testing in 2000 and now uses her in all its side-impact crash tests both in the driver seat and in the rear seat behind the driver. "The 5th-percentile female is also similar in size to the average 12- or 13-year-old child, who is most often in the rear seat," explains the IIHS' Lund. "This allows us to measure the potential of injury to those youngsters as well."


It is my understanding per disscussions with SK that this is the dummy used to test the upper weight limits of the seat.

In addition to the placement of the shoulder harness, the effectiveness of pelvis restraint plays a large part of how the rest of the body reacts in a crash.
In Nascar testing, it was found that seats and restraint systems that did not provide adequete protection against submarining allower an average of 5 inches of spinal and chest compression. Seats and restraint systems that do prevent submarining allowed an average of 1.5 inches of chest and spinal compression.By restraining the pelvis, there is less energy for the shoulder harness to absorb, keeping the chest from being compressed.

Nascar goes on to explain the seat belt geometry that best restrains the pelvis. The attachment points must provide the optimum geometry to minimize movement of the belts. Lap belts perform best when they act at an angle between 45 and 55 degrees relative to the longitudinal axis of the vehicle. This angle permits the lap belt to react to the upward pull of the shoulder harness. A system installed with a shallow belt angle permits the shoulder harness to pull the lap belt up off the pelvic area and into the abdominal region, which greatly increases the chances for internal injury.


Shoulder harness placement also, of course, affects spinal compression. The following is Nascars guidelines.

The end attachments of the shoulder harness must also be installed at appropriate angles. The ideal position is anywhere between five degrees below and 30 degrees above the driver’s shoulder.

If the upper attachment point falls significantly below the driver’s shoulder, then a spinal compression injury is likely to occur. In an accident, the shoulder belts pull down and back on the torso as they resist the forward motion of the driver. The resultant restraint force compresses the spinal column and will add to the stresses in the spine already caused by the force of the crash impact.
This is why the general rule is at or above ffing. Official Nascar rules thus state

The shoulder harness cannot be
secured more than 1" below the driver's shoulder.


Just as a point of interest, although it is not the focus of this conversation, Nascar also states

In the opposite situation, if the trailing ends of the harness are too far above the shoulder (greater than 30 degrees), then two problems can occur. First, tension in the shoulder harness is increased and undue stress is applied to the harness and its structural attachments. Second, excessive angle will cause excessive motion. If the harness belts are too far above the shoulder, they will provide little resistance to forward motion of the driver’s upper torso. The result is an impact with the steering wheel and the possibility of neck injury. The shoulder straps should also be three to six inches apart behind the driver’s neck to prevent slippage off the shoulders.


If you measure the angle between where a child's shoulders would be if 2 inches above the top slot (this is where my ds shoulders are if I stick books under his bum to make his ears even with the top )and where the harness passes through the back of the shell, you have approximately a 7 degree angle.

The low profile and close set crotch strap and 50 degree angle between the attachment points for the hip straps and the buckle are right in line with Nascar's recommendations for best pelvis restraint. This would result is a great reduction in chest and spinal compression.

Just so you all know, I do NOT like the Radian, even though I own 2 of the things. I believe it is a great nitch seat, ( I really need two seats that fit this "nitch" otherwise I would have ditched these things already) It is hard to install, the instructions are needlessly inflexible, and it is a total PITA to to adjust the straps. But for me, the options are limited to the Radian or putting my 5 and 8 year old children in a lap only belt.

There is an AMAZING amount of engineering that goes into any car seat design. It is way more involved than the hard and fast set of rules that have been drummed into our heads. There HAS to be innovators in the field willing to figure out ways to do what we have all been told is impossible or we will never make progress. It wasn't all that long ago that we didn't have HWH at all because everybody said that it just wasn't done. The first HWH seats on the market (Fisher Price Futura, and Super Elite) didn't sell well at all, and one reason was consumer distrust. other innovations such as reverse belt paths and infant cs bases also were met with high levels of distrust.

As for me, I will without a seconds hesitation use my Radians with shoulders above the top slots. Both because I trust that SK is not under any cercumstances willing to open themselves up to the huge lawsuits that would result if a child was injured because they allowed something so basically against the rules without doing their homework first ( and honestly, the ruling fits with the practices of the leading source of crash data, NASCAR), and because I have done my own homework. This isn't to say that a year down the line SK and I won't both be proved wrong. But for now, this is the best information I have to go on.

I understand that my children would be safer if the harnesses where above their shoulders, but I also believe that they are safe with them below in the Radian 80. Whether or not you choose to follow SK guidelines, or go with the time honored ones is up to you. It is truely a parental choice to make. I don't advocate my choices to anyone, )this includes my seat choices, erfing, ehnessing, chest clips, convertables vs infant seats, etc) that is not my job. My job is to educate. I can and do offer my opinions, but I also try to accurately represent both sides of the issue whenever possible.

That is what I am trying to do now, fill in the missing pieces of info. We all know why over the top slots isn't allowed in general. We all deserve the other pieces of the story so we can EACH make informed choices.

Kimberly

Mom to Becky, 11 yrs old, 90 lbs in adult belt most of the time, Danny, 8 yrs old, 52ish lbs in a Husky and a Radian 80(1 inch below top slots) and Hope 5yrs old 60 lbs in a Radian 80( 2 inchs below top slots)
 
Last edited:

joolsplus3

Admin - CPS Technician
Hey, um, guys? Read the Regent manual...if it's the same as the Husky manual, it absolutely DOES say that you can use the top slots as long as the tops of the ears are under the seatback. I'm seeing the NEW manual doesn't say that (page 4), http://www.britaxusa.net/support/Regent_R2.pdf.pdf and you should correct them (KDMF), but for 5+ years now it's been common in all Britax manuals to say it's ok to use it over the top slots ;)
 

thepeach80

Senior Community Member
I thought the whole Regent over the top slots thing was due to just bad manual writing (I find for such an expensive seat, they don't write their manuals well). If you called them, they would've told you you couldn't use the seat if the shoulders were over the top slots.
 

joolsplus3

Admin - CPS Technician
I thought the whole Regent over the top slots thing was due to just bad manual writing (I find for such an expensive seat, they don't write their manuals well). If you called them, they would've told you you couldn't use the seat if the shoulders were over the top slots.

But still, in that case, does that make KDMF wrong for repeating it? I don't think so. Britax put it in the manual, KDMF copied it, nothing wrong with that at all.

Britax needs to quit starting rumours and letting their CSR's make up different rules from what are in the manual, don't they? Sigh...

(And I agree, as we know, I've never been a proponent of using seats when the top slots are below the shoulders...I'm glad the new manual is clear...gee, if it was that easy to fix, maybe they could have done it years ago?).

All I'm saying is, KDMF is innocent in this case.:whistle:
 

bombedier

Senior Community Member
I just saw this thread - Yes - we took the wording and direction from the old Regent manaul - I didn't realize that the new manual had revised this. I will make sure I correct thing on all our communication moving forward.
 

Car-Seat.Org Facebook Group

Forum statistics

Threads
219,656
Messages
2,196,897
Members
13,530
Latest member
onehitko860

You must read your carseat and vehicle owner’s manual and understand any relevant state laws. These are the rules you must follow to restrain your children safely. All opinions at Car-Seat.Org are those of the individual author for informational purposes only, and do not necessarily reflect any policy or position of Carseat Media LLC. Car-Seat.Org makes no representations as to accuracy, completeness, currentness, suitability, or validity of any information on this site and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. If you are unsure about information provided to you, please visit a local certified technician. Before posting or using our website you must read and agree to our TERMS.

Graco is a Proud Sponsor of Car-Seat.Org! Britax is a Proud Sponsor of Car-Seat.Org! Nuna Baby is a Proud Sponsor of Car-Seat.Org!

Please  Support Car-Seat.Org  with your purchases of infant, convertible, combination and boosters seats from our premier sponsors above.
Shop travel systems, strollers and baby gear from Britax, Chicco, Clek, Combi, Evenflo, First Years, Graco, Maxi-Cosi, Nuna, Safety 1st, Diono & more! ©2001-2022 Carseat Media LLC

Top