basic tethering questions

[ProudMomof5]

Okay I feel so ignorant about this.... but I have some questions.

Why do we need to use tethers? I mean I guess it'd be to keep the top part of the carseat in place, right? but why?

What happens if you don't use a tether and you are in a car accident?

Does tethering have something to do with the child's weight?

Do you HAVE to have them with certain car seats?

[Melizerd]

Tethering reduces the amount of head excursion in an accident (how far the head moves forward) so it's always recommended to tether. All seats do pass without the tether unless they REQUIRE it at some point.

The Britax Regent requires a tether after 50lbs I know for sure, I'm not sure if there are others. I think some seats require top tether used when LATCH is used too. Hopefully someone else will pipe in with the full answer.

Older cars can usually have at least one top tether installed, some for free.