Why are booster seats more safe than just a seat belt for children?

[bayleaf]

Can anyone help me out here? I know they ARE more safe - and would never dream of not using one - but a friend who is offering my child a lift doesn't always bother for her 2 ( aged 4 and 5) as ''her car is a big volvo and very 'safe'''. I feel like a neurotic twit for insisting dd (aged4) has a booster seat to use in her car as I feel she is safer that way - but I don't actually know WHY she is safer ( OK, I know the belt 'sits' better - but why is that safer?)and would doubtless feel less stupid if I knew...Hope someone can tell me - the searches I have done just tell me that it's safer - but not why

I think it bacause it puts the child up higher so the belt fits better.

so the straps are in the right place

As per spookymieow and nailpolish.

...except I would go stronger, think seat belts without a booster seat are positively dangerous for smaller children

a seatbelt without a booster could damage internal organs in a crash as it cut accross the abdomen

a booster should enable the belt to go over the
lap

there are new regs coming in next year (I think) that ensure all children (under 11 or under 1.5m) use a booster

how's her volvo "very safe" then? Does it have a crash-proof forcefield around it?

lol!

I just read that the booster seat prevents damage to the abdomen and spine in the event of a crash.

Means that the lap belt and diagonal belt fit properly. If the child is sitting too low, the diagonal belt cuts under the chin, across the throat instead of over teh shoulder and I believe there is a high risk of neck injury in a crash.

My kids were once sent home from nursery with a Rospa leaflet on why they need to be in child restraints - it's been giving me nightmares ever since.

OH thank you - I KNEW mumsnetters would know the answers - and quick too! Turns out that the volvo has an inbuilt booster seat in the middle which she can use - so my worries are over tho a part of me is still shocked that a really normal, intelligent mum (who I like a great deal )should be so casual about something that to me seems so incredibly important.