Talk to me about fusing of the spinal column

When and how does it happen, how much difference does it make, etc. I thought it doesn't start fusing til age 3-6 or something like that, but seems like most everyone is fine with FFing a 3 year old. Or is it beginning to fuse earlier and not completed til age 3-6 (or is that number not even real).

Basically I have a 30 mos old 32.5 lb DS who I'm afraid to turn FFing when he hits 35, but I'd like to know if my fears are justified or just paranoid. He's just had a growth spurt and seems to be plateau-ed off now and I estimate a couple more months before 35 lbs.

The following images are helpful when attempting to convince parents to keep their toddlers RF . . . maybe they'll be helpful here, too....

• Cervical spine developmental comparison : 2 year old (left) vs. 6 year old (right)
• Thoracic spine development comparison : 2 year old (left) vs. 6 year old (right)
• Lumbar spine developmental comparison : 2 year old (left) vs. 6 year old (right)

Although, personally, I find these images best suited to convincing parents not to put their toddlers/preschoolers in boosters yet.

I agree... because it shows that while they are fused at about age 3, they just aren't as solid as they are at age 6, when the hips are solid enough to do a good job at preventing submarining in a booster that positions the belt correctly.

And then it helps explain that then the bones still aren't as solid as an adults until 13-14 yrs old, which is another reason the back seat is essential so a child isn't in front of an airbag.

Bone density is a hard one for people to understand, as they aren't able to just look at their kid's bones.

Fusing of the spinal column isn't something that happens instantly, it's progressive the same way that the skull fusing happens starting over the first few months of life. Fusion of the spinal column is usually complete sometime between the ages of 3 and 6, though it could possibly happen sooner in some kids. Basically the fusion process is in progress at one year old, closer at 2yrs, possibly done at 3yrs, but could take as long as 6yrs. The more it fuses the less stretch it has and the lower the risk of ff'ing injuries.

As children get older and their spinal columns get closer to fusing they become better able to tolerate the forces in a high speed frontal collision. It's worth saying that not every young ff'ing child suffers severe spinal injuries in a collision, it is very dependent on the forces involved in the collision itself, combined with proper restraint of the child and installation of the child seat. In high speed collisions we do see head and neck injuries even in 3 and 4yr old ff'ing kids - but we also see them in adults.

I think that the 3yr old mark some people use really just comes down to personal limits, and that by that point the benefit is less measurable making it ok. There always continues to be a benefit however small it might be, but at some point the benefit is so small that it becomes a case of choice as to what works best for the family.

those pictures are awesome! i had never thought of RF vs. FF as an issue of how the spinal column is functioning but it definitely makes sense when thinking of those teeny children in boosters. my child will definitely be harnessed for as long as possible, though i did FF him at around 32 pounds because he is very tall for his age and wasn't comfortable facing backwards.

So really it doesn't matter when it's completely fused because at some point during the process the strength becomes adequate?

Those images are great. The URL title says 1yr_6yr. I wonder if it's at some point between 12-24 mos that the picture represents.

What other physiological factors are at play in the RF vs FF of a child over 2? I'm hoping once I understand the why a bit more I'll be better able to assess what the right decision is for our family. He'll RF to 35 lbs regardless (he loves it and it's easy for us to do, he fits, etc) but I'd like to feel comfortable when the time does come to turn him. I'd like to stay away from the legalities of importing if there's no real reason to RF a 2.5+ year old. I know it's safer for everyone, but obviously he won't RF into middle school, lol, so I need to be comfortable at some point anyway!

papooses said:

The following images are helpful when attempting to convince parents to keep their toddlers RF . . . maybe they'll be helpful here, too....

• Cervical spine developmental comparison : 2 year old (left) vs. 6 year old (right)
• Thoracic spine development comparison : 2 year old (left) vs. 6 year old (right)
• Lumbar spine developmental comparison : 2 year old (left) vs. 6 year old (right)

Although, personally, I find these images best suited to convincing parents not to put their toddlers/preschoolers in boosters yet.

Click to expand...

The ages you have for the photos are wrong.

The photo on the left is a 1 year old and the photo on the right is a 6 year old.

I posted the orginal photos on the BBB board a few years ago. They are from a text book I have when studying Human Osteology

I'll post back with a link to the original post.

I can look it up in some other texts when I'm next at the Physical Anthropology lab, but from my lecture notes, we were told that the earliest fusion in the spine is at 3 yo. All kids are done at 6 yo. Bone fusion is the joining together of bone, and the process really starts in utero. The bones keep growing and complete growing between certain age ranges. The last bone to fuse is the clavicle at around 25 years of age.

ETA. Here's a link to the original post with the pictures.
http://windsorpeak.com/vbulletin/showthread.php?t=180970

In the comments, there's more talk about the density of the bone. Bone density increases over time and through force exerted on the bones. Bone density can also be decreased if no forces on our body - the use it or lose it. There's a better explanation by another poster on post #11.

The bones I've dealt with of an infant are much lighter and not as robust, as that of an older child. They aren't as dense because not as much force exerted on them - walking running etc. Think about our little babies that have no muscle strenght, but that develops as they age and use the muscles. It's similar with bones.

I had DS RF until 3 yo. I was going to go for longer, but had surgery and no voice for several weeks. DS freaked out when he couldn't see or hear me. 3 yo is the absolute min. for me to turn FF.

What I like about these photos is that it shows people that their child isn't like someone who is older. Many people want kids to be a big boy or big girl and ride forward facing or in a booster. Well, they're not like an older person. Physiologically, their bodies are different and they need more protection.

I will say that your son is a lot older than my son when he started ffing. I turned him at just over a year at 26 pounds. He was in a comfort sport that only rfed to 30 pounds. He also weighed 36 pounds at 2 so even with the true fit my daughter is in he would have turned before 2. I know that probably doesn't make you feel any better about your decision but I thought it might help for a reference point. My son is 4.5 years old from what I have read 30 pounds was pretty good at the time. His snugride only went to 20 pounds.

niccig said:

ETA. Here's a link to the original post with the pictures.
http://windsorpeak.com/vbulletin/showthread.php?t=180970

Click to expand...

:thanx!: That link gives me trouble every now & then . . . or it's my rrreeeeealllllyyy weak internet connection...? A doctor actually scanned those for me & explained them really quickly -- as if it was inconsequential :thumbsdown: So, thank you very much for the correction & more detailed response! I will correct my site [tomorrow when I'm on a more secure server]

Is it OK to link the pictures to that thread?