Shoulders no more than 1 inch above (top) strap slot - why?

[AislinCarys]

I'm asking this because it seems impossible to get a correct answer whether this applies to Swedish seats. Most Swedes have never heard of it, a few have and insist it must be followed, the traffic authority (which is the authority on car seats) does not mention it, and Brio doesn't answer inquiries .

So we'd like to know why this rule is. Does anyone of you know?

We've found out that the Swedish seats are designed very differently from the US seats, which is why they can be used rear-facing until ears at top of shell (which is also how they can recommend that kids rf at least until 4 or 5, preferably 5, because nearly all kids can, in the erf seats). So we're sort of hoping to work out how whatever the rationale is for the rule applies to the Swedish seats.

We're choosing between keeping our Brio Zento (where DD has well over 5 inches left until her ears are at the top of the shell, but only just over 1 inch until her shoulders are 1 inch above the top slots), or selling it and buying a Radian (where DD might have 2 inches left until outgrown by any of the rules).

[LaughingHyena]

I'm in the UK and I've never seen the rule of shoulders not being more than 1 inch over the top slots. We have 2 britax seats, both of which say the seat can be used till the child ears are at the top of the hard plastic shell. Though I suppose it would be an unusual child who's shoulders were more than a iinch above the slots but still had their ears below the shell.

You've got me interested now so I'll be waiting to see what others say.

[AislinCarys]

It varies how high on the shell the top slots are. The Brio Zento has quite a high back, but low slots, in comparison with others (almost three inches lower than the radian's top slots).

[AislinCarys]

I just got a reply from someone on a Swedish forum, who'd contacted NTF (the Swedish traffic authority) directly. The reply she got from them was that for rearfacing carseats, the safest is that the shoulders are at or BELOW the top slots. However, to ride rear-facing with shoulders above the slots (to any height, not specifically 1 inch) is still (and I'm translating directly here), significantly safer than riding forward-facing.

[AislinCarys]

Although I'd still be interested to hear if anyone knows what would happen if a child's shoulders are above the slots, in a collision!

[BathrobeGoddess]

Here in the States it is shoulders at or above slots for rear facing and at or below slots for forward facing. Has something to do with spine compression...