Question about the Car Seat Lady's post today - boosters don't take any force?

[EmmaCPST]

http://www.facebook.com/TheCarSeatLady/posts/272321252877371

Bolding is mine, and what I have a question about.

Did you know that one of the best backless boosters (and THE BEST for carpool, 3-across, and travel) is now even better? The BubbleBum booster is now available in black!

For those who might have qualms about using an inflatable seat, here are a few facts to understand:
1. Boosters are positioning devices - their job is to make sure the seat belt starts AND stays on the proper part of the child's body. Boosters do not take any of the forces of a crash. Boosters don't restrain the child - the seat belt does 100% of the restraining. (This is very different from car seats with 5 point harnesses - as car seats ARE the restraint and DO take the forces of a crash - which is why car seats must be tightly installed)
2. The Bubble Bum's inflatable part is made of life-raft material (i.e. very strong) and has an inner memory foam core with 3 air chambers.
3. The inflatable part is SEPARATE from the structural part. The cover contains a web of seat belt material that provides structural support - and it is on this webbing structure that the red metal belt guides are attached.
4. The Bubble Bum passed all US and European crash tests in the inflated AND deflated state (so should the worst case scenario happen and it deflates, it will still work). But please, use it only in the inflated state.

I've always been taught that the "artificial hips" function of a booster actually does take some force in a crash, thus absorbing force that the child's pre-pubescent pelvis doesn't have to.

 

[Qarin]

I've always been taught that the "artificial hips" function of a booster actually does take some force in a crash, thus absorbing force that the child's pre-pubescent pelvis doesn't have to.

This has been said here a lot, but I've never quite figured out at what point in a (pure frontal) crash the seatbelt would put pressure on the arm rests of most boosters (where the belt path is under and forward of the arm rests) at all.

 

[Brianna]

There was some discussion of this last year http://www.car-seat.org/showthread.php?t=196213

 

[joolsplus3]

high five to anyone who can find the study I've posted before with pictures of post crash boosters that are crushed on the sides under the armrests....I'm too distracted right now to find it

 

[MomToEliEm]

high five to anyone who can find the study I've posted before with pictures of post crash boosters that are crushed on the sides under the armrests....I'm too distracted right now to find it

Here is a link to a study that you posted a while back. On page 6, it shows a picture of damage on a booster.
http://www-nrd.nhtsa.dot.gov/pdf/esv/esv19/05-0366-W.pdf

 

[Syllieann]

How do we know that the booster deformed from taking pressure from child rather than due to it's own weight against the belt? It doesn't make sense to me from a physics perspective how it would take the force off the child. The KWP has no problem playing to that though. I'm not sure I'm buying their shock absorbers.

 

[RubysGirl]

I just looked at the pdf, and if you look at the last pages they show stills from the crash tests. All of the boosters are folded onto themselves from the force of the seat cushion pushing forward. I bet that has more to do with the damage than the seat absorbing pressure from the child.

 

[gsdguenter]

But wouldn't the damage that is done to the arms of the booster be done to the child if there were no arms?

 

[Brigala]

But wouldn't the damage that is done to the arms of the booster be done to the child if there were no arms?

I don't see why. The child isn't attached to the booster.

 

[bree]

I could see how a booster could take some of the forces from a seatbelt in an accident. The booster is in contact with parts of the seatbelt that otherwise would be in direct contact with the child's body. I think that simply by virtue of preventing the entire seatbelt from being in contact with the child's body that a booster would have to absorb some of the forces from the seatbelt in a collision, because the booster is going to be in contact with the seatbelt during the collision, too. :twocents: