Rear-facing - THANK YOU!!

dkdean

New member
We (18 month old DD and I) were involved in a slight fender bender this morning--rear ended at a light. I was stopped at a light and the guy behind me apparently slowed, but then didn't stop. So, he wasn't going very fast when he hit us. The jolt was enough to throw my shoe (flip flop) off my foot but didn't cause any damage to my car (some to his).

I am just so happy and thankful that I have Em rear facing...Obv it wasn't a big hit, but it was enough to move me (and my shoe)--and I know it would've been an even bigger hit to her in she was FF. I knew that she was cradled in her BLVD and went with the impact instead of having her neck 'thrown' forward during it.

So, thank you for helping to keep me informed so that I can keep my kids safer in the car.

Kim
 
ADS

southpawboston

New member
good to hear no one was hurt.

however, from a purely physics perspective, i fail to understand how being RF in this particular instance (straight on rear end impact) caused less impact to your DD by being RF. :confused:

i think you have it backwards.

if she were FF, the impact would have driven her into the carseat. by being RF, the impact drove her away from the carseat.

when you are rear-ended, things inside your car want to move rearward. when you rear-end the car in front of you, things inside your car want to move forward.

i'm not trying to be anti-RF. just keeping facts straight. RF is still safer all around than FF, and up to 500% safer in side impacts, but in this particular instance i don't think that your DD was jolted less from being RF. but good for you that your 18 mo is ERFing. :thumbsup:
 

abigaylebelle

Active member
I'm confused now. If I am stationary and something hits me from behind I will move forward then back. That's why people get whiplash from being rear-ended. So wouldn't a child in a rearfacing seat first move back into the shell and then rebound?
ETA: the flip flop went forward in the crash, otherwise it wouldn't have come off the OP's foot
 

Madeline410

New member
It's still forward motion. Once you are hit from behind, you are pushed forward, right? Therefore cradling DD into her seat makes perfect sense to me! So glad no one was hurt!
 

gecikuh

Senior Community Member
I'm confused now. If I am stationary and something hits me from behind I will move forward then back. That's why people get whiplash from being rear-ended. So wouldn't a child in a rearfacing seat first move back into the shell and then rebound?
ETA: the flip flop went forward in the crash, otherwise it wouldn't have come off the OP's foot

the major forces in a crash are going toward the thing you hit. when you hit something with the front of your car, the major forces are throwing you forward (this is statistically the more common collision, which is what makes RFing so great!). when something hits the back of your car, major forces are going backward, which unfortunately isn't superhelpful for a RFing child.

RFing is still the way to go when possible!!!! ....just trying to help clarify.
 

dkdean

New member
I thought through it too...thinking that rf'ing is not necessarily the best for severe rear-end collisions. But, our bodies did move forward--which for Em would've been backwards.

My foot was on the brake and when I was hit, I let my foot off the brake, therefore moving with the bump (although not going far enough to hit the car in front of me) instead of staying stationary.

I was the passenger in an accident when we were rear-ended by someone travelling 60mph (we were stopped). The police said that due to my mom taking her foot off the brake and going with the impact, made a huge difference in distributing the impact.


Maybe I am thinking about it wrong still...
 

Mama Jo

New member
I was the passenger in an accident when we were rear-ended by someone travelling 60mph (we were stopped). The police said that due to my mom taking her foot off the brake and going with the impact, made a huge difference in distributing the impact.

In that case, the impact was directly to the car. The car moved in the direction it was pushed. Passengers in the car are sitting still. Your bodies want to stay where they are, but they are forced to move with the vehicle because they are secured to the vehicle with the seatbelt. The head is not. It essentially wants to stay where it is, while the rest of the body moves with the car, which leads it to being thrown backward in relation to the rest of the body.

Think of it like this... If you are standing on a skateboard, and someone comes from behind and kicks the skateboard forward, your body will fly backward in relation to the skateboard. In reality, your body is not actually moving backward, but staying where it's at, while the skateboard moves forward.

Now in a vehicle collision, you have other variables in place, such as rebound and restraints, so it's not an exact comparison... but for visual purposes, it's the same basic principal.
 

southpawboston

New member
the major forces in a crash are going toward the thing you hit. when you hit something with the front of your car, the major forces are throwing you forward (this is statistically the more common collision, which is what makes RFing so great!). when something hits the back of your car, major forces are going backward, which unfortunately isn't superhelpful for a RFing child.

RFing is still the way to go when possible!!!! ....just trying to help clarify.

right. that's what i was trying to clarify, without trying to dismiss the importance of RF in general.


It's still forward motion. Once you are hit from behind, you are pushed forward, right? Therefore cradling DD into her seat makes perfect sense to me! So glad no one was hurt!

you are forced to move forward with the car, relative to the ground. but relative to the car, you are pushed backwards inside the car, relative to the car. it's not the direction of motion that defines impact, it's the rate of acceleration or deceleration that's the defining factor.

when you rear-end the person in front of you, your vehicle experiences rapid deceleration. naturally, things in motion tend to stay in motion, so objects not bolted to your car (such as the occupants) continue to move in the same direction, with a rate of deceleration less than that of the car.

when you are rear-ended, the car experiences rapid acceleration. and just as things that are in motion tend to stay in motion, things at rest tend to stay at rest. therefore, as you are rear-ended and your car rapidly accelerates forward, objects in the car that are not bolted down want to stay at rest, which is the same as moving toward the back of the car.

(imagine a race car taking off at the green light. what happens to the driver? does he lurch into the steering wheel or does he get thrown back into his seat? he gets thrown into the back of the seat-- same as being rear-ended!!!)

I'm confused now. If I am stationary and something hits me from behind I will move forward then back. That's why people get whiplash from being rear-ended. So wouldn't a child in a rearfacing seat first move back into the shell and then rebound?
ETA: the flip flop went forward in the crash, otherwise it wouldn't have come off the OP's foot

people get whiplash because their necks are rapidly moved back. that's why we have head restraints, which minimizes the injury. without them, there would be nothing to prevent the neck from moving even farther rearward. it's not the rebounding forward that causes the whiplash, it's the initial rearward motion.

as for the flip flop-- my interpretation from a physics perspective is that the driver's foot or leg got propelled rearward during the impact (as would be expected). the sudden rearward motion of the foot caused the foot to simply slide out of the flip flop while the flip flop was being pressed against the brake pedal. think about it-- how do you take a pair of flip flops off without using your hands? with your foot on the floor, you take the weight off, and pull your leg back. your leg slides out and the flip flop stays where it is. that's what happened here.
 
Last edited:

southpawboston

New member
I was the passenger in an accident when we were rear-ended by someone travelling 60mph (we were stopped). The police said that due to my mom taking her foot off the brake and going with the impact, made a huge difference in distributing the impact.

the cop was correct! the reason the impact was less by keeping the foot off the brake is that the rate of forward acceleration from the impact was reduced, relative to keeping her foot on the brake. it's hard to visualize, but think about it this way. if her foot was on the brake, the car would have sustained far more crash force. by allowing the car to roll forward, some of that crash force was converted into kinetic energy in the form of making the car move forward. does that make sense?

it becomes instinctual after awhile. i was rear-ended 18 years ago, and i can still remember watching in my rear-view mirror and knowing that it was going to happen. my gut instinct whenever i'm at a stop light and i see a vehicle approaching me too quickly from behind, is to let go of the brake pedal, for exactly the reason mentioned above. :thumbsup:
 

dkdean

New member
the cop was correct! the reason the impact was less by keeping the foot off the brake is that the rate of forward acceleration from the impact was reduced, relative to keeping her foot on the brake. it's hard to visualize, but think about it this way. if her foot was on the brake, the car would have sustained far more crash force. by allowing the car to roll forward, some of that crash force was converted into kinetic energy in the form of making the car move forward. does that make sense?

it becomes instinctual after awhile. i was rear-ended 18 years ago, and i can still remember watching in my rear-view mirror and knowing that it was going to happen. my gut instinct whenever i'm at a stop light and i see a vehicle approaching me too quickly from behind, is to let go of the brake pedal, for exactly the reason mentioned above. :thumbsup:


Me too...I think when you've been hit like that it does just become instinct!!!


I didn't think this would start such a conversation!!! I am enormously happy though that it was a bump and not a serious accident we had today. And, that my DS (who was not in the car at the time--4.5yrs/in Regent) and DD (RF in BLVD) are as safe as I can have them in a vehicle. We can just do the best we can with the information we have!!!
 

southpawboston

New member
I didn't think this would start such a conversation!!! I am enormously happy though that it was a bump and not a serious accident we had today. And, that my DS (who was not in the car at the time--4.5yrs/in Regent) and DD (RF in BLVD) are as safe as I can have them in a vehicle. We can just do the best we can with the information we have!!!

i think it's GREAT that it started a conversation, because it's one thing to be told to do something because it's safe; it's another to understand why. IME, information is a GOOD thing. i hope that by understanding the basic physics of car crashes, people can better informed about car safety. i think it would behoove anyone who is interested in car safety to understand the concepts. no need to know hard physics, just the basic concepts of force and motion!
 

dkdean

New member
Oh Yes! I completely agree!!!! I think it's interesting b/c I had thought through the physics of it afterward...b/c I knew that rear racing with a rear impact wasn't supposed to be more effective than FF'ing...but then I thought about what my body did and applied it to what I thought Em's body did. So, I started thinking that maybe it was b/c we 'rolled' with the bump instead of absorbing it...and then I posted here :) The conversation has made me think through it even more...and thinking is always a good thing!!! When we know better, we do better!!!
 

snowbird25ca

Moderator - CPST Instructor
And just to throw another monkey wrench in, despite the physics which say a rf'ing kid in a rear-impact collision should have a similar type of force placed on them as a ff'ing kid in a frontal collision, rf'ing kids still seem to fare better than adults in terms of injuries in rear impact collisions.

I've heard of a few instances now where the adults were all sore after being rear ended but the rf'ing kids didn't have any injuries.

So who knows the reasoning behind it, but in terms of actual injury, it seems like rf'ing kids still come out better in rear end collisions than occupants who are facing the front of the vehicle. :shrug-shoulders:

OP - Glad that you and your dd weren't injured badly.
 

dkdean

New member
And just to throw another monkey wrench in, despite the physics which say a rf'ing kid in a rear-impact collision should have a similar type of force placed on them as a ff'ing kid in a frontal collision, rf'ing kids still seem to fare better than adults in terms of injuries in rear impact collisions.

I've heard of a few instances now where the adults were all sore after being rear ended but the rf'ing kids didn't have any injuries.

So who knows the reasoning behind it, but in terms of actual injury, it seems like rf'ing kids still come out better in rear end collisions than occupants who are facing the front of the vehicle. :shrug-shoulders:

OP - Glad that you and your dd weren't injured badly
.

Obviously, I agree!!!


And, another thing I was thinking is that this also goes to prove that FF or RF is part of it, but not all of it--My seats are installed correctly and are checked each and every time we get in the car; the harness straps are in the appropriate position and are snug; the seats fit each of my children and my vehicle. Those are also pieces that have been reinforced via this board :)
 

safeinthecar

Moderator - CPS Technician
And just to throw another monkey wrench in, despite the physics which say a rf'ing kid in a rear-impact collision should have a similar type of force placed on them as a ff'ing kid in a frontal collision, rf'ing kids still seem to fare better than adults in terms of injuries in rear impact collisions.

I've heard of a few instances now where the adults were all sore after being rear ended but the rf'ing kids didn't have any injuries.

So who knows the reasoning behind it, but in terms of actual injury, it seems like rf'ing kids still come out better in rear end collisions than occupants who are facing the front of the vehicle. :shrug-shoulders:

OP - Glad that you and your dd weren't injured badly.

RFing kids do well in rear end collisions because the CR seat back flexes toward the back of the vehicle and helps the head, neck, and spine stay in alignment and move together as one piece. Even seats with tethers and anti-rebound bars flex toward the back of the car to some degree, just not as much because the tether/ rebound bar deforms and flexes to absorb some of the crash energy.

Basically what happens is that you are sitting still (well, unless you are moving, in which case getting rear ended just causes you to suddenly speed up) and the impact from behind pushes the vehicle forward under you. When you "catch" on parts of the vehicle, then you start getting pulled along too. Because of the way rfing car seats are attached, there is a fulcrum that allows the car seat to move toward the back of the car with the child, instead of the child being thrown into the harness.

And to clarify, whiplash is a sprain to the muscles and ligaments in the neck and back from HYPEREXTENDING the neck. It can and does happen in frontal crashes, I've had it happen to me (frankly, I'd rather endure natural childbirth while standing in line at DMV than ever have whiplash again).
 

southpawboston

New member
And just to throw another monkey wrench in, despite the physics which say a rf'ing kid in a rear-impact collision should have a similar type of force placed on them as a ff'ing kid in a frontal collision, rf'ing kids still seem to fare better than adults in terms of injuries in rear impact collisions.

where was this data from? could you forward me the source?

I've heard of a few instances now where the adults were all sore after being rear ended but the rf'ing kids didn't have any injuries.

well, that's not a proper comparison-- comparing adult injuries with child injuries can't generate meaningful conclusions. it's hard to attribute it to the fact that kids were RFing and adults weren't. it's also possible that it was simply a matter of age difference, or location within the vehicle. either way, unless there's a study showing this data, it's pure conjecture as to why the difference exists. in the absence of a study, physics would dictate otherwise.

again, i believe in the advantages of RF and don't dispute any of the data out there, but i feel like sometimes the true benefits get stretched simply for the sake of trying to convince people (as is what i suspect happened to the OP). i prefer that people draw conclusions based on data-driven observations, not conjecture. i love data. i'm a data junkie. can't get enough of the stuff :).

EDIT: safeinthecar, we posted at the same time. do you have an information source on rear-end collisions and RF? i'd like to see it. your explanation makes some sense, but i wonder if that is just what is believed happens or is there actual data to show it is what happens.
 

An Aurora

Senior Community Member
And just to throw another monkey wrench in, despite the physics which say a rf'ing kid in a rear-impact collision should have a similar type of force placed on them as a ff'ing kid in a frontal collision, rf'ing kids still seem to fare better than adults in terms of injuries in rear impact collisions.

Purely anecdotal, but we were rear-ended by a car going around 45 mph while we were stopped at a light. The Volvo that hit us was totalled, while our car had no visible damage. DH and I had whiplash that took months of chiro care to help, and 9 month old DD1 slept through the crash.
 

Defrost

Moderator - CPSTI Emeritus
where was this data from? could you forward me the source?

In order for the forces of a rear-impact to equal those of frontal-impact, the car would need to be moving in reverse at the same speed as the car moving forward that it's being compared to.

So, say you're driving 20mph and get hit head-on by another car driving 20mph. That is NOT comparable to the crash forces generated if you're driving 20mph (or at a stand-still) and get rear-ended by a car doing 20mph. The only way you could create the same crash forces as the first example would be if you were driving 20mph in reverse and hit a car driving 20mph.

Um, I'm not good at math, but I can still see that an impact between two vehicles traveling in the same direction, or with one vehicle stopped, are going to create crash forces considerably lower than if they're traveling toward each other.

Right?
 

southpawboston

New member
In order for the forces of a rear-impact to equal those of frontal-impact, the car would need to be moving in reverse at the same speed as the car moving forward that it's being compared to.

So, say you're driving 20mph and get hit head-on by another car driving 20mph. That is NOT comparable to the crash forces generated if you're driving 20mph (or at a stand-still) and get rear-ended by a car doing 20mph. The only way you could create the same crash forces as the first example would be if you were driving 20mph in reverse and hit a car driving 20mph.

Um, I'm not good at math, but I can still see that an impact between two vehicles traveling in the same direction, or with one vehicle stopped, are going to create crash forces considerably lower than if they're traveling toward each other.

Right?

defrost, you make perfect sense and i understand this. i know that in general, most rear-end accidents are milder than frontal. my question was, where's the data to support the following statement:

rf'ing kids still seem to fare better than adults in terms of injuries in rear impact collisions

i'm interested to see the data, because this doesn't seem at all like a meaningful comparison. we're comparing RFing kids with FFing adults. that's apples and oranges. a better comparison would be to compare RFing kids versus FFing kids in rear impact collisions. i would love to see the data on that, and whether it refutes the laws of physics, which would dictate that an RFing kid in a rear-end collision is the same as a FFing kid in a frontal collision, assuming that both impacts were of the same magnitude.
 

Pixels

New member
So, say you're driving 20mph and get hit head-on by another car driving 20mph. That is NOT comparable to the crash forces generated if you're driving 20mph (or at a stand-still) and get rear-ended by a car doing 20mph. The only way you could create the same crash forces as the first example would be if you were driving 20mph in reverse and hit a car driving 20mph.

Well, if both vehicles are moving forward at 20mph, and one manages to rear-end the other with significant force, there's something wrong. :p

Seriously, though, two vehicles hitting each other head on, each moving at 20 mph, will strike each other with the same force as one vehicle moving 20 mph into a brick wall, or one vehicle moving 40 mph into a stationary vehicle.
 

Car-Seat.Org Facebook Group

Forum statistics

Threads
219,656
Messages
2,196,896
Members
13,530
Latest member
onehitko860

You must read your carseat and vehicle owner’s manual and understand any relevant state laws. These are the rules you must follow to restrain your children safely. All opinions at Car-Seat.Org are those of the individual author for informational purposes only, and do not necessarily reflect any policy or position of Carseat Media LLC. Car-Seat.Org makes no representations as to accuracy, completeness, currentness, suitability, or validity of any information on this site and will not be liable for any errors, omissions, or delays in this information or any losses, injuries, or damages arising from its display or use. All information is provided on an as-is basis. If you are unsure about information provided to you, please visit a local certified technician. Before posting or using our website you must read and agree to our TERMS.

Graco is a Proud Sponsor of Car-Seat.Org! Britax is a Proud Sponsor of Car-Seat.Org! Nuna Baby is a Proud Sponsor of Car-Seat.Org!

Please  Support Car-Seat.Org  with your purchases of infant, convertible, combination and boosters seats from our premier sponsors above.
Shop travel systems, strollers and baby gear from Britax, Chicco, Clek, Combi, Evenflo, First Years, Graco, Maxi-Cosi, Nuna, Safety 1st, Diono & more! ©2001-2022 Carseat Media LLC

Top