Mythbusting Archive

It’s been a while since any myths have been busted around here and I think that it’s about time we get back to setting the records straight. This is one that is of particular interest to me because I have a stake in both sides of the issue.

Myth: Your Pediatrician has been educated in child passenger safety and is the best source of information on when to turn your child forward-facing or stop using a booster.

In the many years that I’ve been involved in the child passenger safety field, one of the most common reasons I’ve heard for turning children to forward face too soon or to switch them out of a car seat altogether is “my pediatrician said it was fine.” So I thought maybe it would be good to look at whether a pediatrician is a good source of car seat information. Now, let’s be clear, I love pediatricians. I married a pediatrician. I don’t want, for even an instant, to imply that physicians are anything other than extraordinary human beings. I just want to delve into whether our pediatricians are good sources of information on car seat safety.

First, let’s look at medical school education. The first 2 years of medical school are spent in classrooms listening to lectures, memorizing information and taking absurdly difficult tests. The second 2 years are where med students do rotations in clinics and hospitals and look really scared a lot (I kid, I kid).

The curriculum in the first two years includes: gross anatomy, developmental anatomy, radiographic anatomy, histology, biochemistry, genetics, neuroanatomy, neurophysiology, immunology, pharmacology, ethics, nutrition and often an elective or two. Looking closely at that list, while they are learning about a lot of the principles that our car seat knowledge and decisions are based upon, there’s not any actual education on car seats in medical school.

So maybe residency then?

A general pediatrics residency lasts 3 years and includes insanely long hours and a lot of very hard work. These 3 years are divided into hospital and clinic-based work where most learning is done through hands-on experience and then hours of journal and text reviewing at home. During a pediatrics residency, the resident will spend weeks/months in most major specialties including (but not limited to) pediatric neurology, immunology, pulmonology, cardiology, intensive care, gastroenterology, etc.

The American Board of Pediatrics does provide a single line about car seats in the learning specifications for pediatric residents. It states that they should be able to “recommend appropriate car restraint systems, including car seats, based on age and weight of the child, including those appropriate for premature infants.” It should be noted that this is a single line in an 80-page document of learning objectives, so while it’s there, it’s not a significant portion of the education of a resident.

I think it’s also important to note that outside of CPST training, there really isn’t a class that residents can take to learn about this. There typically aren’t talks about it at conferences or other frequent opportunities to be educated about it, so many times these physicians are looking at the exact same sources that parents are. I know that my husband never received any training in car seats in his residency and that my research on car seats was essentially the first he had ever heard about rear-facing beyond infancy. While child passenger safety is undeniably important for pediatricians and their patients, it is not medicine and it’s understandably not their area of focus.

Notably, the AAP (American Academy of Pediatrics) does have an updated policy statement on car seat usage, which is pretty much what your pediatrician should be telling you about car seats, if anything. The most recent revision, from 2018, states:

“Infants and toddlers should ride in a rear-facing car safety seat (CSS) as long as possible, until they reach the highest weight or height allowed by their CSS’s manufacturer. Most convertible seats have limits that will permit children to ride rear-facing for 2 years or more. Children who have outgrown the rear-facing weight or height limit for their CSS should use a forward-facing CSS with a harness for as long as possible, up to the highest weight or height allowed by their CSS’s manufacturer. Children whose weight or height is above the forward-facing limit for their CSS should use a belt-positioning booster seat until the vehicle lap and shoulder seat belt fits properly, typically when they have reached 4 ft 9 inches in height and are between 8 and 12 years of age.”

CONFIRMED, PLAUSIBLE OR BUSTED? With the exception of a few wonderful CPST pediatrician hybrids, this myth is BUSTED.

Pediatricians are hardworking, intelligent people and outstanding sources of information on myriad topics related to your child(ren), but when you need specific safest practice information on car seats and boosters, NHTSA, Safe Kids, this very website or a local CPS Technician are usually much better options.

There aren’t a lot of absolutes in child passenger safety. Just when you think something is a hard and fast rule, like, never use lower anchors and seatbelts together, companies (I’m looking at you Clek and Nuna) decide that’s okay for one or more of their seats. Today we’re going to examine another “rule” that is commonly perceived as an absolute.

Last month we ran an article on the new rear-facing law in California and in it, there was a picture of a child in a rear-facing convertible seat that, from the camera angle, looked like it was touching the front vehicle seat. If you actually looked at the picture more closely, it’s not, but it didn’t stop a lot of people from being confused about it and indicating some frustration that the picture showed misuse. But, did it? Even if the rear-facing seat was touching the back of the front seat, does that always mean it’s being used incorrectly?

Myth: a rear-facing car seat is never allowed to touch the vehicle seat in front of it.

I decided the first place to look was the CPS Technician training curriculum. I read through the rear-facing section and the airbag section and…nothing. There is nothing specific in the curriculum that says that a rear-facing car seat touching the front seat is inherently forbidden. This doesn’t mean that it might not be, but it’s clearly not one of those hard and fast rules that we teach technicians to teach to parents.

So, since it’s not in the curriculum, we’ll have to dig into this differently.

Let’s stop and look at why people think it’s forbidden. The first explanation I heard was that it prevents ride down time (time for the crash forces to be dissipated) for the child and the child restraint. I hear that concern, but I’m not sure it’s actually valid. Think about rear-facing seats with load legs that make contact with the vehicle floor. Also think about rear-facing seats which allow what we commonly refer to as “European beltpath routing”. Euro belt routing means the shoulder belt portion of the seatbelt is routed behind the shell of the rear-facing seat, limiting its ability to rotate down in a frontal crash. All of these things essentially do the same thing that a car seat making contact with a front vehicle seat does. We know the crash test data for those seats are almost universally better than seats without load legs or Euro beltpath routing so this theory doesn’t hold water. Touching the vehicle seat back should not result in greater crash forces being directed onto the child.

The second explanation I’ve heard is that it de-activates the front seat’s airbags. My research on this shows many articles without references, but I can’t find any official word on it that speaks for all cars. My very unscientific experiment showed that no matter how hard I pushed against my husband’s passenger vehicle seat, it did not cause the airbag to turn off with my husband sitting in the seat. Obviously this isn’t hard or fast proof and shouldn’t be assumed to be as much.

Do any car seats explicitly allow touching? The answer is yes.

• Diono allows their rear-facing convertibles to lightly make contact with the front seat. This allowance can be found on their website under the title “Bracing”.
• Britax rear-facing only seats and convertible seats also allow it as per the FAQ section of their website.

There are many other seats, more than I could list and more than I have time to verify, that do not mention it at all in their manuals. We have confirmed that Chicco allows their rear-facing only seats (KeyFit & Fit2) and convertible seats (NextFit) to make light contact with the front seat after being properly installed, however this is not stated anywhere in the manuals or on Chicco’s website. Therefore, we suggest you call Chicco yourself to confirm this information since we are unable to provide you with a direct link to this allowance.

Do any seats forbid it explicitly? The answer is also yes. The most significant of these is Evenflo, whose rear-facing only seats, Embrace, Nurture, LiteMax & SafeMax Infant, all require 1.5 inches of space between the child restraint and the vehicle seat when the car seat is installed in an outboard seating position. This information can be found under the subtitle “Location Warnings” (usually on or near page 5 in the instruction manual). This rule does not apply when these infant seats are installed in the rear center seating position of the vehicle. This 1.5″ space rule also does not apply to any Evenflo convertible seat.

Okay, so no clear consensus for car seat manufacturers. What about vehicles?

I looked at my vehicle’s manual (2015 Honda Odyssey). I read the airbag and child safety sections thoroughly and nowhere does it forbid a car seat from touching the front vehicle seat. It DOES say that if there’s no front seat passenger and the airbag light doesn’t switch to the OFF position, it could be because a car seat is touching the vehicle seat back, but it never says not to do this. So it looks like this pressure, at least in my car, will actually prevent the airbag from turning off, rather than resulting in it not deploying if it’s supposed to.

For good measure I checked my husband’s as well, since they are different companies and both have advanced airbags. Unlike my Odyssey, my husband’s Nissan Rogue does seem to forbid it, though not in very certain terms. In a troubleshooting section, they said that if the airbag light is not working as expected, “(m)ake sure that a child restraint or other object is not pressing against the rear of the seatback.” I would assume this is as good as saying don’t do that, but then it also forces the question is touching the same as pushing?

This might be the heart of the issue. Is light touching of a car seat likely to change the airbag function? I would argue no. If you’re putting less than 2 pounds of pressure (which seems to be an allowable amount of weight in seat backs for airbags) on the vehicle seat, then you are unlikely to impact the function of the airbags. If you’re unwilling to take that risk, it’s understandable and that’s your choice. But I think we should be clear that there is a difference between forceful touching, where the vehicle seatback is deformed from pressure of the seat, to light contact where the car seat and vehicle seat are merely contacting one another.

So what about crash mechanics? I’d like to make a somewhat unverified assertion here and you can evaluate it and decide if it has merit on your own. A child restraint making light contact with a vehicle seat in a crash seems less likely to cause damage to the child restraint and the child than a child restraint that isn’t close to the vehicle seat and slams into it during a crash. The forces involved in hitting the front seat during the initial downward rotation of a frontal crash seem far more problematic than the front seat limiting some motion of a car seat in a crash. I don’t have any links handy to prove this theory, but it makes sense that slamming into a vehicle seat during a crash will generate higher impact forces than not slamming into it.

Touching vs. Bracing: What’s the difference?

The term “bracing” has been used in many different ways over the years but the consensus seems to be that bracing means more than just light contact. The definition of the word brace is “anything that imparts rigidity or steadiness”. If your rear-facing car seat is “braced”, that means it’s relying on the front seat for support. To my knowledge, no car seat manufacturer allows this as it may alter the recline angle or otherwise affect the installation of the car seat. As stated in the Britax FAQ (pictured above), your rear-facing car seat should be installed securely first and then the front seat should be moved back and/or reclined until it makes light contact.

What about sliding a piece of paper between the rear-facing car seat and vehicle seat? 

Sometimes a CPS Technician will tell a parent or caregiver that if they can slide a piece of paper freely between the back of the [properly installed] rear-facing car seat and the front seat, then it’s not a problem. This is a reasonable comment in many situations since it’s a concept that is easy to understand and visualize even if you don’t literally slide a piece of paper between the two. However, this isn’t a “rule” and it’s not mentioned anywhere in the technician training curriculum or in any car seat manuals that I’ve noticed. This is simply a teaching tool that someone came up with years ago and many of us said, “hey, we like that analogy and we’re going to use that when we educate parents too.”

So what’s the verdict?

Kind of busted, but only because I wrote the statement, “a rear-facing car seat is never allowed to touch the vehicle seat in front of it”, as an absolute truth.

Some rear-facing seats cannot make contact with the vehicle seat in front of them because the car seat manual forbids it. Some rear-facing car seats cannot make contact with the vehicle seat in front of them because the vehicle manual forbids it. But, if neither the car seat manual nor the vehicle manual expressly forbid it, your car seat can lightly touch the vehicle seat in front of it.

So the official decree is, as always, read your manuals thoroughly before installing your car seats!

Anyone who has had a baby in an infant car seat has faced the grocery store dilemma- what to do with baby while you’re shopping? Especially a sleeping baby. And I know we’ve all seen what seems like the easiest answer- putting the infant seat, with baby, into the top part of the grocery basket.

There are signs posted on the infant seat and virtually every car seat manual says that you shouldn’t do this, but, is it really as unsafe as the signs lead us to believe? Is there a reason we can’t make use of this incredibly useful position for baby? Let’s find out.

MYTH: Infant car seats can safely “click” into the tops of shopping carts if you hear an audible “click.”

First, I would like to clarify that yes, there once was a seat that specified in the manual that you could do this (the Baby Trend Flex-Loc), however, the current manual does not allow it. So let’s set aside that seat/manual for the remainder of this discussion because it’s no longer true of that model of car seat.

As CPSTs, we counsel parents on this one quite a bit, mostly because nearly every infant seat manual specifically states not to put the car seat on top of the shopping cart. But do we know that it’s actually dangerous? The answer is sort of.

Uppababy Mesa Manual

The Consumer Product Safety Commission has put forth a document describing the injuries to children related to grocery charts from birth to age of 5. Within that report, they state that

“Of the 12 incidents reported as falls, three involved a car seat with the child in it falling from the shopping cart; of these three incidents, one was a fatality and one involved a hospitalization. The fatality occurred when a 3-month-old boy fell while secured in a car seat that was not secured to the shopping cart after the cart was pushed over a speed bump in the parking lot.”

More on that terrible tragedy in a moment. It further states that,

“There were nine incidents coded as “other,” covering a range of hazards. Five of the reports concerned failures or inadequacies of the restraints in the shopping cart seat (including one involving a car seat); none resulted in injuries.”

So, it’s clear that a car seat improperly placed on a grocery cart can cause injury to an infant. Upon further searching, the single death cited by the CPSC did involve an infant seat in the top of the grocery cart. In a news report on the child’s death they report that the seat was placed in the part of the car closest to the push bar, where a toddler might sit, which is precisely the myth we are discussing.

Chicco Keyfit Manual

Just in terms of design, a cart can be very top heavy if not properly balanced. Anyone who has tried to stand on the bottom basket while pushing has felt that tipping motion and you can imagine if you have a 20 pound child in a 12 pound car seat, it wouldn’t take much for the cart to tip and the child to be injured. But I think there’s another piece to consider.

Your rear facing only car seat is made to click into one style base. You cannot put a Graco infant seat in a Chicco base because the locking mechanisms are not interchangeable. And the same is true for an infant seat and a grocery cart. You may hear an audible “click” but that does not mean that the seat is actually locked in because you have no way of knowing if the shape of the grocery cart is similar to the shape of your infant seat base. The part of this is that because the shape of a grocery cart won’t be the same as the shape of your base, trying to click it onto the cart might actually ruin the locking mechanism of your car seat. And you wouldn’t necessarily be able to see that or know that it wasn’t working until it was stressed by a crash.

Nuna Pipa Manual

Yet another hazard is a potentially broken shopping cart. The carts are used by dozens of people each day and they will break down over time. How terrifying would it be if this was your car seat with your child in it?

And last but not least, car seats are not meant to be used for long durations outside of the car. I know it’s convenient, believe me, I’m guilty of using my car seat for a few more errands than I should, but that doesn’t mean it’s safe. Car seats are meant to be at a very specific angle and if they are too upright, as they often are in strollers and grocery carts (especially when in the top of the cart) baby may not be able to breathe properly. And, obviously less seriously, excessive use of infant car seats can result in flattening of the back of baby’s head (brachycephaly), which may require use of a head orthosis to correct later on.

Graco Snugride Manual

VERDICT: Between every manual and grocery cart forbidding it, the CPSC report and the potential to break your car seat, I think we can call this one BUSTED. Even if your car seat seems to “click” into the cart, that doesn’t mean it’s safe to be left there.

If you need to take your baby grocery shopping, you have a few safer options than the top of the cart. You can wear baby in a carrier or sling, you can bring baby in a regular stroller and use the stroller basket as your cart (this is what we do the most), or if you really need to use your infant car seat, you can place it in the big part of the grocery cart and put the rest of the groceries elsewhere. But the best option in my opinion is to get someone to babysit so you can stroll the aisles, childfree, as if you’re on vacation. Not that I do that or anything!

Please please please, don’t put your infant car seat in the top of a grocery cart. It may seem secure, but it only takes a split second for your infant to become a statistic.

Myth: Backseat baby mirrors present a life threatening danger specifically as a projectile in a crash.

There are a lot of black and white things about child passenger safety. Always read the manual. Always follow the manual. Harness should always pass the pinch test. But when you get outside of those black and whites, you’ll find that there’s a lot of gray. And that gray can be almost exclusively be explained as parental discretion. As CPS Technicians we can give you suggestions about things that may or may not be dangerous, but we don’t always have the hard evidence for these things like we do for the black and white things.

One such gray area are the mirrors that attach to the rear vehicle seat head restraints so that parents can see their rear facing babies and toddlers (and preschoolers!). There are some CPS Techs who will tell every single parent that these are patently unsafe and are a projectile. Other CPS Techs use them in their own vehicles. So which is it – are they deadly projectiles or perfectly safe? Or neither?

Alright, so let’s look at the science:

Well. Technically there is none. No studies on this to cite, no federal safety standards that mirrors have to pass in order to be sold, but I don’t think that means we can’t come to a decision based on evidence. Let’s look more abstractly at the science. Specifically, how does speed impact the effect a projectile can have on a child? For this, we have to go back to high school physics. The force an object exerts is equal to that object’s mass times its acceleration. So let’s apply this to mirrors.

Based on a quick Amazon search, the average weight of a mirror is around 1 pound, which is equal to .45kg. So let’s say you were hit while traveling 30 miles per hour or 13.41 meters per second (for simplicity’s sake we’re going to say this happened in 1 second. This is not mathematically accurate, I am aware). If Force = mass x acceleration, the force of the mirror would be equal to .45kg x 13.41m/s, which comes out to 6.03N (newton). I know what you’re thinking. Cool math, Katie. But what does it mean?

What is 6N in real life? What does any of this mean?

6N is equivalent to the force of hitting your child with a 5 pound object traveling at 5 miles per hour. Or throwing 10 pound object at your child traveling 3 miles per hour. Those all exert the same force and it’s not a trivial amount of force.

Don’t worry, I’m not going to linger on the math. Basically, an object exerts more force when it’s moving quickly than when slowly, so a 1 pound mirror seems pretty insignificant, but when it’s traveling at 40 miles per hour, it will dramatically increase the force it exerts on whatever it hits.

But, is it deadly?

Well, for it to strike the child, first, it would have dislodge from the vehicle headrest. There are a variety of ways that mirrors attach to the headrest. Some attach to the vehicle top tethers, others buckle or hook to plastic hooks around the top or back of the headrest. There is a chance that these attachments could break or fail in a crash, and logically, it would be more likely for a heavy mirror, like the ones with batteries and moving lights and music speakers, to break from its attachment than a light one (back to that force equation- the heavier mirrors impart more force, so the straps have to be able to restrain them).

Assuming the mirror did dislodge, the injury to the child would depend greatly upon the speed of the crash, the weight of the mirror and I would also argue the design of the mirror is also worth considering. Obviously a heavy mirror will exert more force and a lighter one less and a faster crash will likewise increase force, and a slower force will increase it less. But I think we also need to consider that a mirror with a thick plastic edge is likely going to result in a more significant injury than a mirror with a soft/padded edge just due to the way it will strike a person, even if it is with the same amount of force.

After a solid google search, I haven’t been able to find mention of any injuries from backseat mirrors and certainly no fatalities from them. In terms of physical injuries caused by mirrors, I think we are left to assume that it is possible for a child to be injured by a poorly attached heavy mirror that becomes dislodged in a crash at a high speed.

Before we rule on this myth, are there other dangers we’re not considering with regard to mirrors?

As a CPS Technician who makes the personal choice to use a mirror, I can tell you without question that they can be distracting. It’s easy to spend just an extra second checking to see if baby is asleep and in that second, if the traffic ahead of you stopped suddenly, you would be at risk for a significant collision. Likewise it’s easy to miss hazards in the road, someone changing their lane into yours, etc. Anytime you take your eyes off the road, you put yourself and your child at risk. I personally believe (and again, I’m not anti-mirror, I use one in my vehicle) that a parent can be distracted enough by a backseat mirror to cause a crash.

So, what about our myth?

Verdict: This myth is a tough one. We have no scientific proof that it has happened or will happen, but I think when looking at the physics, it is PLAUSIBLE.

As a CPS Technician, I tell parents fairly frequently that I do not recommend using mirrors, but if they are going to, there are a few things they can do to lower the risks associated. First, make sure you pick one that is as lightweight as possible. The Brica Vivid Reflection Baby In-Sight Car Mirror and JJ Cole 2-in 1 are among several that are lightweight plastic with soft edges. I’m not endorsing any particular product but some appear to be less risky than others.

Second, make sure that it is well attached to your vehicle head restraint. Again, designs and attachment systems vary a lot from one product to the next and some appear more secure than others. Give it a good hard tug and decide if you think that it would stay put in a 30 mile per hour crash.

And, most importantly, I think, remember that it is a distraction and that distracted driving is deadly driving. If you’re going to use a mirror, check it as briefly and sparingly as possible. If you find that you are getting distracted by it, take it off. If you don’t give your children food or toys with small parts you don’t have to worry about choking and other car seat issues can be triaged when you arrive at your destination or take a pit stop.

I’m sorry we weren’t able to get a more clear answer on this, but I think that it’s an important topic to discuss. Please feel free to offer other suggestions or information you may have found in the comments section.