Pictures of spine development: the reason a baby should not face forward (edited)

All the safety experts say it's safest for a child to rear face as their spine is not strong enough to protect the spinal cord if they are forward facing. It's not strong enough because the vertebrae are in pieces joined by cartilage. The vertebral arch has not fused into a complete circle of bone, which will enclose and protect the spinal cord.

I'm studying Human Osteology, human bones, for archaeology, and I have to learn about skeletal development. This picture is in my textbook, (White, T. Human Osteology, 2000)the classic text for this subject.

In the first picture there is a cervical vertebrae for a one-year old (left), and beside it a cervical vertebrae for a 6 year old (right). Note that the 1-yr old's vertebrae is still in pieces.

http://pic20.picturetrail.com/VOL133.../293669158.jpg

In the 2nd picture, thoracic vertebrae for a 1 yr old (left) and for a 6 yr old (right). Note that the 1-yr old's vertebrae is still in pieces.

http://pic20.picturetrail.com/VOL133.../293669157.jpg

In the 3rd picture, lumbar vertebrae for a 1 yr old (left) and for a 6 yr old (right). Note that the 1-yr old's vertebrae is still in pieces.

http://pic20.picturetrail.com/VOL133.../293669156.jpg


The vertebrae do not begin to fuse until age 3-6 years old. This is why rear-facing is the safest as it gives more support and protection to the incomplete vertebrae and therefore the spinal cord. With vertebrae in pieces, a forward facing child has a greater chance of damage to the spinal cord when their head and neck whip forward and back in a crash.

To see what I mean by crash forces a child experiences in a crash, go to http://www.cpsafety.com/articles/stayrearfacing.aspx
Scroll down the page to read the section titled "Why should my child rear-face past 1 year and 20 lbs?" for an explanation of crash forces and look at the crash test videos of forward-facing and rear-facing seats, the videos are at the bottom of the page.

We have car seats that allow children to rear-face up until 30-35 lbs, each seat varies. For many children this is well into their 2nd year if not older, and closer to the age when their vertebrae are fused. We just need to use the seats rear-facing to give children more protection in a crash.

I just thought some people here might be interested in these pictures.

Nicci


ETA: Link to crash test videos, more information about crash forces in an accident, and typos

very interesting! i get a lot of flack from other mom friends for not turning DD around, but we just won't do it! There's no good reason TO turn them around other than wanting to see them and interact with them from the front seat...IMO...that's not a compelling argument...

Wow, that is compelling! I always just thought they were "softer", but didn't picture what "fusing" meant.

Cartilage is between the bones and it will be replaced by bone as the bone grows over it. It just takes time for it to completely fuse into a solid vertebrae.

The human body is amazing. I've also seen femurs that aren't completely fused, that doesn't happen until teenager years, or a child's skull. It just blows me away how a child grows.

Nicci

I'm glad you titled this so well. It will make it easier to find as I'm sure everyone will be referring to it often! Thanks!

Wow, that is very interesting to see! Thanks so much!

Wow, great pictures. I wish that avi was not such a big kid. He was RF as long as possible, until 17 months. It makes me so sad, he was so big but would still be RF if he weighed less but i know people who have 2 year olds that weigh 25 lbs and are FF.

UGH

Ilana, aka Nana to my sweet nephew Avi

http://lilypie.com/pic/060403/hfNw.jpg[/img]http://b2.lilypie.com/h2bbm7/.png[/img][/url]

Makes me wish we had those swedish seats where they can rearface to 5 or 6 yrs old. But we have the seats that we do, and we can use them as long as possible for our kiddos.

Wow those are compelling...thank you for posting these pictures, they are a great reference.

Thank you very much. One question someone asked me if there are pictures for older children? Or when the vertebrae has formed into one piece, it would now only be the issue of density?

Thanks again.

hmm, well, that's a great question. not sure i can do it justice, but i'll tell you what i remember from skeletal development from grad school. hopefully someone with more knowledge/expertise will chime in.

our bones lay down increased densities according to a principle called Wolf's Law (http://en.wikipedia.org/wiki/Wolf's_law). basically, we lay down new/additional bone _over time_ wherever there are sufficient forces put thru an area of bone to encourage an increased density to support those forces.

so i think it holds true that part of what stimulates a growing childs body to put down bone in the place of this initial cartilage are the increased forces going thru those areas. these increased forces come from external things like gravity pulling on an ever increasing body weight as we progress thru development into more upright postures (sitting and then standing) and also from internal forces (muscles and tendons pulling directly on certain areas of bones).

so in the case of the growing childs spine, the density of the bone (and therefore the forces it could withstand) would be a combination of the age of the child (level of expected ossification as well as _time_ for that ossification to take place) along with the stage of development of that particular bones density based on the external and internal forces it had been exposed to. essentially, the only thing that really buys them safety is time... time for the bone to ossify and time for wolf's law to accomplish the laying down of additional density relative to the forces the body experiences.

does that make sense?? hope it answered it at least in part. let me know if i need to clarify.

lori
Sam 5/19/05 How lucky I am that you chose me.

Tam,
I only have pictures for 1 and 6 yr old. I can tell you that the parts of the vertebrae keep fusing into early adulthood. The sacrum is made up of 5 sacral vertebrae and they all fuse together sometime from teenager to about 20 or so. It's an ongoing process.

Lori - great answer. I just answered a question on my final about Wolf's Law, and I wish I was as succinct as you were.

Nicci

>Tam,
>I only have pictures for 1 and 6 yr old. I can tell you that
>the parts of the vertebrae keep fusing into early adulthood.
>The sacrum is made up of 5 sacral vertebrae and they all fuse
>together sometime from teenager to about 20 or so. It's an
>ongoing process.
>
>Lori - great answer. I just answered a question on my final
>about Wolf's Law, and I wish I was as succinct as you were.


heh, thanks, gotta dust out the cobwebs sometimes to remember thru the mommy brain fog, but it's all good :). great thread btw.

re: "it's an ongoing process" i'll just add a 'someone might find it interesting' side note from my clinical practice. it's not only an ongoing thing as we grow up, but also as we age. like the wikipedia article above points out, wolf's law works in reverse as well. when we don't put forces thru our bones, they lose density over time. one of the best things we as women can do to prevent or slow bone loss (osteopenia/osteoporosis) is weight bearing/resistance exercise - keeps wolf's law working in our favor and keeps our bones strong longer :).

Thanks ladies!!!

WOW! Thanks for that info. You just eliminated the rf/ff choice for me! DD is just 1 yo & about 20 lbs. We were so excited for that ff milestone, I was looking to skip convertibles and go straight to a ff only seat.
The posts on these message boards were slowly convincing me that rf is best, and I am now completely sold.
Definitely passing this info on to my friends! ;)
Tx!
ShanaMama

>We were so
>excited for that ff milestone, I was looking to skip
>convertibles and go straight to a ff only seat.
>The posts on these message boards were slowly convincing me
>that rf is best, and I am now completely sold.
>Definitely passing this info on to my friends! ;)
>Tx!
>ShanaMama

I'm excited to be nearing the "2 year birthday and still rear facing" milestone. ;)

My son is 23 months. I did have him front facing for a week when I was driving a 2 door car briefly last month. Honestly, he kept fighting to get his legs stretched out to rest on the front seat. It was like he was trying to figure out what to do with his legs, "They can't just hang here, can they?" He went back RF when I got my sedan back. He promptly crossed his legs and fell asleep on his first ride back RF.

I posted the photos because eventhough you read the safety information about RF/FF and babies' spines, it's nice to see a photo that shows what's going on. I'm glad you found it useful. I had already decided to keep DS RF, but when I saw these comparisons, and comparisons of other bones, I was even more sure he will stay RF as long as possible.

A question I have now though, is do I pass this information on to RL friends. I've spoken with several about extended RF, and they all keep their children FF (same age as DS). Do I now email these photos, or is that overstepping things as they've never asked for more information. I don't want to be the annoying friend that shoves information down their throats, and imply that their not being as careful as they can. What to do?!

Nicci

Nicci, I think if you present it a certain way ("I just learned this in my anthropology class and was blown away! I thought I'd share it with you.") it should be fine. They say a picture is worth a thousand words, which is why the crash test video comparisons of a rear-facing and forward-facing seat are so nice, but that isn't enough for some people. They think because they have a "strong" baby that FF is fine, or because the doctor said so, FF is fine. But possibly seeing that a human child's bones are not fully developed until age 3-6 might make a difference.

Thank you for the information!

Scatterbunny, you made a good suggestion. All my friends know I was up to my ears in bones, I could send an interesting facts about your child's bones. I just don't know how to word the "they should be RF" part, I don't think they'll make the link unless I state it.

Maybe I could have some other photos that I have (skull, femur etc) and then say "and here are pictures of vertebrae, the left is a 1 yr old and the right is a 6 yr old. See how they're in 3 parts, this is why babies can't forward face in the car as the vertebrae in the neck aren't strong enough. They'll fuse into a complete vertebrae by 3-6 years, as you can see in the 6-yr old photo" and leave it at that, they could then draw their own conclusions about FF/RF. They all know I keep DS RF for safety reasons. I want to share the information, but I don't want to lecture them either.

What do people think?

Nicci

Sounds like a good idea!

Thanks for the info!

I definitely want to keep DS RF as long as possible. He's just about 20 lbs at 13 months. So when do you know you MUST go FF? I've read too many conflicting answers to know for sure.

Caroline

http://b2.lilypie.com/3k5Am7/.png

http://www.gynosaur.com/assets/ribbo...n_gold_12m.gif

They "must" go FF only when they are too heavy or too tall for the particular seat to be used RF.

The weight limit is strict. If the seat is 33 lbs max, then at 33 lbs even, the child must go FF. (Or buy a bigger seat.) RF weight limits are 30, 33, or 35 lbs depending on brand.

Height limits are less defined. They have to say a certain number of inches, but the reality is some kids are all leg, some all torso. In RF, you WANT them to be above the slot (to hold the child down in the seat).

You have to read the manual to find out what the rule is regarding the where the head needs to be in relation to the seat's back. That's the biggie for RF height rules.

Don't worry about their legs. Their legs are fine!! Most kids are completely comfy and don't care about having their legs crossed, etc. My son went briefly FF at 22 months when I was driving a tiny car for a week. He'd stretch his legs madly to try and reach the front seat and rest them there. He didn't know what to do with his legs FF. When I got my car back, he happily crossed his legs and fell asleep RF.

Most kids do outgrow seats by height before weight, something to keep in mind and check for.

Thanks for posting this. Now maybe I can convince my DH to leave the carseat as it is. He's been just WAITING for Bright to turn one and to be 20 lbs so he can turn the car seat around. But I keep telling him to just leave it. Maybe NOW he'll be convinced.

bump for newcomers...

I was thinking of editing my original post to include links to the videos of FF and RF crash tests. I referred to the crash forces a seat undergoes, but not everyone knows what it looks like when a seat is in a crash. What do people think?

Nicci

I think that's a great idea! That way people see it right up front (before they get bogged down by all the other wonderful, but time consuming posts - heehee)......

I added a paragraph with a link to the videos, and corrected some typing mistakes. I hope the link to the videos and the photos together, help in understanding what is going on when a child is in an accident and why rear-facing is best practice.

Nicci

Thanks for posting those pictures!

My son is 23months old, and we have really been considering turning him ff even though our older child was rf past 3 years old..

I was actually coming to ask about it when I saw your post.

He will be staying rf until he reaches the 33lbs for his Britax

*~* bump *~*

*******bumpity bump**********

Thanks for the info and pictures. I'd been wondering if we should turn our DD around when she hits one or if we should wait until she outgrows her seat. We'll wait! There are plenty of years ahead for her to look out the front windows and great rear facing seat toys in the meantime.

Kathy
Mommy to a wonderful baby girl
http://b1.lilypie.com/IX8zm7.png

Bumping this great info.

Wow! I think I will send these pictures to a few friends who are having babies this summer. We kept DS RF until we learned that he was 33 lbs at his 2 yr checkup. Now that he's FF, he rarely ever falls asleep, even in the dark, because it's "too bright" with all of the headlights - he actually requested sunglasses at night a few weeks ago.

I'm glad I came across this in a search. Thank you so much for the info!

Sending over a friend to see this great info!

I have posted a link to this thread in the Car Seat 101 thread at the top of the forum, so it won't need to continue being bumped. :)