What does the top tether do?

[mommy2sammy]

After reading another thread, I realized, and almost embarrassed to ask, but what is the purpose of the top tether? We use it but don't know why...going to hide under my rock now ;-)

[monica-m]

Don't go hide, if you're asking the question, chances are there is a lurker or two with the same question. All of us had to ask questions like this to get educated about car seats in the first place.

For a forward facing seat, the top tether adds another point of attachment for the car seat. It holds the top of the seat back and adds stability. What this does for the child is reduce head excursion (the distance the child's head travels forward) by 4-6 inches. In Canada, top tethering is required by law for all forward facing child seats. Best practice dictates that all forward facing seats be tethered. The top tether is part of the LATCH system. It's the T in the acronym. (Lower Anchors and Tethers for CHildren).

For a rear facing seat, the top tether adds stability and it reduces rebound. In the US, only Diono, Britax and Combi allow for rear facing tethering. These manufacturers include a d-ring with their seats to create a tether point with. There is debate about the benefits of rear facing tethering in general and in respect to using it with newborns and small babies. Britax is the only manufacturer that allows Aussie tethering (attaching the tether to the tether anchor over the top of the seat when the seat is rear facing) but that is generally not used as it is inconvenient to get the child in and out. Most of the rear facing tethering done is Swedish style. Most of the Swedish ERF seats use tethers. One of the reasons why those seats are not available in the US is that in order to pass testing, the seat cannot rely on tethers, foot props, or bracing in order to pass.

[canadianbakers]

Originally Posted by monica-m The top tether is part of the LATCH system. It's the T in the acronym. (Lower Anchors and Tethers for CHildren).

I've always wondered about that - since top tethering isn't required in the US, does everyone still use it (or know to use it) when installing with LATCH? Like, do they realize that it's part of the whole system?

(not really asking you in particular, just a general pondering!)

[mommy2sammy]

Ha! And I thought latch was referring to the actual piece of metal in the vehicle! Thanks for the explanations, we do use it, I just wasn't sure why, lol.

[canadianbakers]

Originally Posted by mommy2sammy Ha! And I thought latch was referring to the actual piece of metal in the vehicle! Thanks for the explanations, we do use it, I just wasn't sure why, lol.

Nope. LATCH is the lower anchors (the ones you use instead of the seat belt) and that top tether all together - for forward facing seats. For rear facing seats, they only use the lower anchors.

[monica-m]

Originally Posted by canadianbakers I've always wondered about that - since top tethering isn't required in the US, does everyone still use it (or know to use it) when installing with LATCH? Like, do they realize that it's part of the whole system? (not really asking you in particular, just a general pondering!)

No they don't realize it. Top tether use in the US is abysmal. I think the last study on TT use put it at around 20%.

[slimy72]

So now I"m beyond curious. What is the debate with RF tethering with Infants? I only ask because from what I understood that was one of my personal requirements in my truck should I ever have another newbie was a RF teetherable seat. I worry about it because the seat is against the back wall of the truck and the window is right there. Am I wrong in thinking that?

[monica-m]

The debate centers around potential neck loads with a RF tethered seat. I personally (THIS IS MY OPINION just to make that clear) would not RF tether a seat for a newborn. The idea is that the tethered seat would cause greater neck loads that could be too much for a noob. The energy would transfer more to the baby than being absorbed in the the rebounding motion. My 2.5 year old's seat is RF tetherd (Radian) but in a situation where I feel rebound would be a bad idea for a newborn (truck with low seat back and nothing between glass and baby) I would opt for a seat with an anti-rebound bar.

[canadianbakers]

Originally Posted by monica-m No they don't realize it. Top tether use in the US is abysmal. I think the last study on TT use put it at around 20%.

Oh dear.

Even though the tether is required by law up here, I'm sure our usage rate wouldn't be near 100%, unfortunately.

[kp1721]

subbing for more opinions on tethering with a newborn