A load leg, which is sometimes called a foot prop or support leg, is a metal pole that comes down from the base of a rear-facing car seat and rests on the floor of the vehicle. 

Crash tests show that load legs significantly reduce the forces on the baby’s head and neck, thereby keeping your baby’s brain and spine safer.

Which car seats have load legs?

Many European seats feature load legs. We are so excited to report that a growing number of US seats now offer load legs as well!

We hope more US seats will offer load legs soon so that more children can benefit. 

How do load legs keep babies safer?

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Load legs reduce downward rotation:  The car seat’s goal is to decrease crash forces on a child’s body. The back of a rear-facing car seat should absorb the crash forces while the remaining forces should be applied onto the strongest part of the child’s body — their back. A load leg allows a car seat to do this better. In a frontal crash, a rear-facing child and their rear-facing car seat will move towards the front of the vehicle. In addition to moving forwards, the car seat will also rotate downwards (i.e. become more reclined) as the vehicle’s seat cushion compresses.

Why is downward rotation a problem? The more reclined the car seat becomes during the crash, the more the child slides up the car seat. When a child slides up the car seat, forces are applied to the child’s neck and shoulders. A load leg works by preventing the car seat from going any more reclined during a crash, which therefore reduces how much the child will slide up the car seat. In so doing, more of the crash forces can be absorbed by the back of the car seat and distributed along the child’s back, rather than into the child’s neck and shoulders. Crash tests of the same car seat with and without the use of the load leg show that using the load leg significantly reduces head injury criteria (HIC).

Load legs limit rebound: Load legs also serve as anti-rebound devices in frontal crashes. Rebound is the movement of the car seat towards the back of the vehicle in a frontal crash. Anti-rebound devices limit how far the rear-facing car seat can move towards the back of the vehicle – which can prevent the child’s head from contacting the back of the vehicle seat during a crash.

How does a load leg limit rebound? Imagine that you’re jumping on a trampoline. For every action there is an equal and opposite reaction. If you take a big jump on a trampoline, you’ll bounce really high up. If you take a tiny jump, you’ll barely bounce up at all. The jump is your action, and the bounce is your reaction – also called rebound. How does this relate to a rear-facing car seat in a frontal crash? Most rear-facing only seats will rotate downwards a fair amount during a frontal crash (like a big jump on a trampoline) and then will rebound towards the back of the vehicle a lot thereafter (like the high bounce you get from that big jump). However, on a rear-facing seat with a load leg, there’s basically no downward rotation (no jump) and therefore there is very little rebound as a result.

Crash test footage of seats with and without load legs

These videos above – one of the Cybex Aton2 and the other of the Clek Liing – show how a load leg decreases how far the car seat rotates downward (as shown by the red line) and how far the car seat rebounds (as shown by the blue line). The green line shows the recline angle of the car seats before the crash – and you can see it’s identical on both seats.

In both videos, two identical car seats are used. The ONLY difference is that one used the load leg while the other didn’t. Notice how both seats with the load leg barely move during the crash. This lack of movement allows the car seat’s shell to cradle the child’s body as best as possible and absorb more of the forces into the shell of the car seat. The motion seen in the Cybex Aton2 & Clek Liing without the load leg is typical of other manufacturer’s infant seats without a load leg.

How do you use a load leg?

A load leg gets lowered until it rests on the floor of the vehicle. The car seat should still rest flush on the vehicle seat, meaning the load leg should not jack the car seat up off the vehicle seat cushion.  

Will the load leg fit in my vehicle?

Since the load leg is not a required feature on US seats – even though it absolutely makes the seat safer – if the load leg doesn’t fit with your vehicle’s floor, you can still install the car seat in that seating position in your vehicle. You’ll just need to tuck the load leg up into its storage area. HOWEVER, we would strongly recommend first considering a different seating position in your vehicle that would allow the use of the load leg before deciding to not use the load leg. 

Which vehicle features may prevent the use of a load leg?

Humps: Many vehicles have a “hump” on the floor in the center seat, where the center floor is raised up. Depending on how high the hump is, the load leg may not fit as the hump may force the load leg to jack the base up off the vehicle’s seat cushion. Some load legs – like on the Clek Liing – can shorten more than others.

For Cybex and GB, the front of the base (the part closest to the front of the vehicle) must make contact with the vehicle seat cushion when using the load leg. For Nuna, if you are using rigid LATCH to install the base, the front end of the base does NOT have to contact the vehicle seat cushion when using the load leg (so long as the base is properly reclined).

Below are statements from Cybex, GB and Nuna affirming that they allow the use of the load leg in cases where there is a hump in the floor.

From Cybex & GB: “It is acceptable to use the Cybex and GB load leg in the center seat even if there is a hump.”(Michael Eppler, Head of Product Management Child Safety for Cybex)
From Nuna: The NUNA Pipa Stability leg can be used on all vehicle floors including the center where a hump is present if the leg fits correctly. The current limitation to the leg feature is in a seating location where a “stow and go” seat or storage area is located beneath the the floor of that seating position as this flooring is in actually a door that cannot handle the forces of the leg in a frontal crash. Crash testing has shown that these doors are not solid fixtures and cannot be used. All other seating positions are acceptable if the leg can be extended correctly and touch the floor, turning the indicator green. (Bob Wall, Nuna Global Advocate, CPST-I)

Hollow Floors: Some vehicles, like Chrysler and Dodge minivans with Stow N’ Go seats, have hollow floors–and the load leg requires a solid floor, so the load leg may NOT be used in these minivans in the 2nd row locations featuring Stow N’ Go seats.

Deep Seats: Some outboard (side) seats may not accommodate load legs if the vehicle seat is very deep – as the load leg may not bend properly over the edge of the vehicle seat. We see this more frequently with shorter bases, like Cybex’s.

If you are not sure whether a load leg is compatible with your vehicle, consult your vehicle owner’s manual AND the car seat manufacturer for guidance.

Consumer Reports Infant Seat Ratings & Load Legs

While its no secret that we don’t always agree with Consumer Reports, we are in 100% agreement that load legs are a key safety feature. In their August 2016 Infant Seat ratings (their most recent to date), 4 out of the 6 seats that earned a “best” in their crash protection rating were those that featured a load leg (crash testing was done WITH the load leg in use on the seats offering a load leg). Since 2016, there are additional seats with load legs that we hope they’ll test soon as well – like the Clek Liing.

Traveling with an infant seat (without the base) and want the same safety benefits that the load leg offers?

Of course you do! The feature that you want on the infant carrier is a European belt path. Click here to learn more about the European belt path. 

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FTC Disclosure: Affiliate links are included in this page. No monetary compensation was provided, however, a few of the reviewed products were supplied by the manufacturer or distributor to help facilitate the review. All opinions are those of The Car Seat Lady, LLC.