Help me understand the booster.

[HEVY]

Boosters were made to help a child fit in the seatbelt properly, right?
HBBs were made for the added safety of side impact, right?

I was wondering why it is you can sit in any booster without touching the floor and not a seatbelt. What's the difference as long as the belt fits properly?

Without the HBB's benefit of side impact why are so many people disappointed/worried/upset to have to use a seatbelt only if a child fits in the belt and passes all steps, and would rather use a NBB where it would make the feet not touch the floor.

Wouldn't that be compromising safety?

[wendytthomas]

The booster also takes some of the forces that would otherwise go to the immature hip bones.

There comes a point, though, where a booster, even with its benefits, is simply too small and starts to hinder.

Wendy

[Maedze]

The floor thing is an issue only because a child in a seatbelt alone who can't touch the floor will slouch to get comfortable.

Because the placement of the belt in a booster is somewhat artificial, the likelihood that a child can slouch enough to compromise belt fit is minimal.

Also, the belt guides in a backless booster act as artificial hips to keep the lap belt in place in an accident. In a prepubescent child, the hips are not as structurally mature as they are in an adult, so even a nbb provides added fit protection even with the 5 step test has been passed.

[Defrost]

The difference is that the feet not touching floor will nearly always result in the belt not fitting properly, even if I can get the kid to sit so that it does - they won't stay that way.

In a booster, the thigh support is generally better, and it's typically harder to much more uncomfortable to slouch down so your feet hit the floor.

I've watched my kids go from backless boosters to just the seat belt, and it really gives them a lot more freedom of movement in all directions. That's okay, I teach them, but it is a learning process, and the older they are, the easier it is to teach them, plus the less likely it is that they'll manage to get the seatbelt as poorly positioned as a smaller/younger child.

[MomToEliEm]

After watching this youtube video of a crash test of a child who may pass the 5-step test (hard to tell about the shoulder belt fitting though), I decided to keep my children in boosters until they don't fit any longer. Even though the seatbelt looks low on the dummy's hips, the child still submarines under the seatbeat.
http://www.youtube.com/watch?v=1yUl4...eature=related

[Kat_Momof3]

the issue really comes down to the knees and thigh support.

you need the knees to bend naturally at the end of the seat.

vehicle seats are all shaped differently, so add to this that a lot of seats are flat or don't have firm edges to support the thighs...

so if you don't have the feet on the floor when there is no booster, you have a child who will slouch for thigh support (feet on the floor give some) or to get the knees to bend properly (I found for Damian, his knees didn't bend over the edge in our vehicles until the feet were able to be flat on the floor)

in a booster, the knees bend over the edge of the booster already (unless a kid's legs are short... and usually, that's with kids who shouldn't be in a booster... or the booster is really deep... in which case I prefer to use a different booster).

for kids whose legs are less comfortable hanging, you can add a very lightweight plastic footstool.

the benefit of the physical containment and the artificial hips added onto the actual hips for a child is there and it outweighs the feet touching the floor.

[HEVY]

Ok, I get it. I always thought the belt path was to just position the belt over the hips, but it makes sense that it also provides protection against the hips. So does a booster, any type really prevent submarining? And is a shoulder belt that doesn't lock more dangerous than one that does?

[wendytthomas]

All shoulder belts lock in an emergency. It's just a question of where it locks beforehand for carseat installation. If your belt doesn't lock in an emergency you need a new belt.

Not all boosters prevent submarining. The three in ones make horrid boosters for this reason. That's why seatbelts need to sit on the kids' bodies, not just go from shell to shell like the three in ones. Also, you need to make sure that the booster fits the child. Piper, for instance, would likely be at risk of submarining in a Compass booster because they're SO wide and she's SO narrow. There's just a lot of extra seatbelt and open space on either side of her. She needs something like a Parkway or Monterey or Nautilus, something that hugs her body.

Wendy

[Judi]

The shoulder belt will lock, in a crash.