Strength and flexibility nexus

[Pooka1]

The cunning and slightly mysterious hdugger brought up the issue of strength and flexibility as it relates to PT treatment approaches for scoliosis.

The ever on point Gayle pointed out that the state of ligaments and other connective tissues control flexibility and that too much flexibility is a bad thing for joints and spines.

As regards scoliosis, it seems that you want the spine to be flexible enough to assume a normal configuration to ever hope to correct a curve with muscle. A flexible spine absent muscle to hold it in place is going to curve and possibly curve quickly. I think this is why braces are thought to not be effective in certain connective tissue disorders which are accompanied by low muscle tone. I would guess that the highest rates of curve progression are probably in this group.

On the other hand, a stiff spine presumably will not curve so much under the weight of gravity though if enough curve is present, gravity will still work to increase the curve over time in most (not all) curves. But maybe less muscle would be required to hold a stiff curve against gravity compared to that required to hold a flexible curve. And indeed a fused curve, the epitome of stiffness, needs no muscle to speak of to maintain the straightness.

Some questions include:

1. can spinal flexibility be increased measurably by exercise?

2. is it dangerous to increase spinal flexibility without simultaneously building muscle to hold it?

3. might it be good to have a stiff spine if it slows curve progression?

4. can muscle be used to artificially stiffen a spine to prevent curve progression? (AKA the $64,000 question)

5. what is the most a person should pay for a hard brace? (AKA the $6,000 question)

[hope404]

Pooka1,

hole in one girl!!!!

My questions exactly !!!!

Now answer 'em for us would ya!! HAHA!!

[Pooka1]

And I think I have a some more.

Is it actually gravity that causes a curve to progress? Or is it over-tightened muscles/ligaments on the (I never get this right) concave? side? And what does gravity have to do with rotation?

That (gravity) is the claim as I understand it. Seems reasonable. Nobody who studies this thinks muscles are causative. The muscles adapt, weaken, etc. in response to the curve because they can't be used symmetrically in the presence of the curve. Anything to do with muscles is a red herring almost for sure. In think rotation occurs as a mechanical consequence of the shape of the vertebra in structural curves. There is something misshapen about the vertebrae that causes the rotation. Note the lack of rotation in that one non-structural curve we discussed.

When children are going through a period of rapid progression, is that the actual spinal bones that are deforming at that pace? It just doesn't seem possible that bones could change that fast. Or, is it the muscles/ligaments doing something at that pace (which seems more likely).

If it was muscle then exercise would have been a proven treatment a long time ago in my opinion. The fact that we don't see that is also consistent with muscle asymmetry being secondary. In the case of my one daughter whose curve moved 5 degrees a month for several months, I do think the bones were remodeled on that time scale. Something has to account for her huge rotation.

If the spine can appear straight when flexible people are bending, why can't they hold it straight when they stand up? That's not all spine, right? Because you can put a brace on them and they can straighten by often up to 50%. So, they can't stand up (50%) straight because their muscles can't hold them that way?

They can't hold it straight because muscles, being secondary, can only do so much. The curved spine is changed. Braces and bending sideways physically relocate the spine well past the ability of any muscle.

Really, I can't figure out how the whole disorder works I'm thinking it's a different thing in kids then it is in adults - kids have a muscle/ligament thing (mostly) while adults grow into having a bony thing (mostly). But that's just a guess.

I don't think it is accepted that AIS is a muscle/ligament issue. In fact I think that has been ruled out. Only a relatively few cases of scoliosis in kids are due to a connective tissue disorder as I understand this though Tonibunny I think has suggested many/most/all? AIS has some connective tissue disorder aspect.

[tonibunny]

Only a relatively few cases of scoliosis in kids are due to a connective tissue disorder as I understand this though Tonibunny I think has suggested many/most/all? AIS has some connective tissue disorder aspect.

IIS, rather than AIS But yes, I wouldn't be surprised if many cases of severe, progressive type Infantile Idiopathic Scoliosis are due to undiagnosed connective tissue disorders. I've just (at the age of 34) been diagnosed with Ehlers-Danlos Syndrome, although I was first diagnosed with Infantile Idiopathic Scoliosis when I was 6 months old. I had a 60+/40+ double curve that developed before I ever sat up - it's clear gravity didn't have anything to do with this curve! However, I wouldn't have had the EDS diagnosed if I hadn't developed other symptoms (most notably Postural Orthostatic Tachycardia Syndrome).

A lot of the IIS children that I know also have joint hypermobility, which can be a symptom of a connective tissue disorder (though there have to be other symptoms for a diagnosis to be made). I think hypermobility in general is something to watch though - it could explain the high rate of scoliosis amongst gymnasts and ballet dancers, since hypermobile kids have a natural advantage in such activities.

[bas2101]

Something more than the shape of vertebrae must be going on with some scoliosis patients. In my daughter's case: high curve at young age (40 degrees at 8), heavy rotation, progression (68 degrees by 12. Now 60 after bracing/Schroth), but with no "vertebral anomalies" as noted in 3 MRI's and x-rays from age 8 to 14.

She is hypermobile, and has noticeably less muscle in her left leg, which is the same side as her major concavity. She also used to complain about leg pain as a younger child (we blew it off as "growing pains" which I now understand do not exist). She also has a "small" syrinx from T1-L2 that was at T5-T12 when she was 8 (this is small?), that 2 neurologists won't touch and can't say whether or not it is causative to her scoliosis. But, without any vertebral anomalies, I just don't get what is really going on, and neither does anyone else, hence the being added to the "idiopathic" pool. My guess is it's the syrinx, since it is expanding in tandem with her scoliosis progression. But why no one will take this possibility seriously is beyond me.

We have been told that over time her vertebrae could wedge, but from what we know now, this is not the case. For those of you that have kids with scoliosis, have you been told that their vertebrae are wedged or deformed in some way?

[Pooka1]

But, if muscles aren't causative at all in the progression (if not cause) of scoliosis, then how does someone like Martha Hawes reduce her curve? She's not reshaping her bones.

Muscles not being causative is not inconsistent with muscle being able to work to some extent in some patients to temporarily hold or partially reverse curves. With Hawes, I think the efforts to expland her chest cavity to help her breathing had a secondary and unanticipated effect on the spinal curvature becauase the rib cage is mechanically connected to the spine. There is going to be some limit on that which she may have already reached. Also, we can't know that her curve would have progressed absent all the PT.

Nothing is reshaping her bones at this point in my opinion.

[Pooka1]

Something more than the shape of vertebrae must be going on with some scoliosis patients. In my daughter's case: high curve at young age (40 degrees at 8), heavy rotation, progression (68 degrees by 12. Now 60 after bracing/Schroth), but with no "vertebral anomalies" as noted in 3 MRI's and x-rays from age 8 to 14.

I think "no verteral anomalies" specifically refers to things like hemivertebrae, NOT wedged vertebrae. I have gotten the distinct impression wedging is veyr hard to image. Linda will know.

She is hypermobile, and has noticeably less muscle in her left leg, which is the same side as her major concavity. She also used to complain about leg pain as a younger child (we blew it off as "growing pains" which I now understand do not exist). She also has a "small" syrinx from T1-L2 that was at T5-T12 when she was 8 (this is small?), that 2 neurologists won't touch and can't say whether or not it is causative to her scoliosis. But, without any vertebral anomalies, I just don't get what is really going on, and neither does anyone else, hence the being added to the "idiopathic" pool. My guess is it's the syrinx, since it is expanding in tandem with her scoliosis progression. But why no one will take this possibility seriously is beyond me.

I agree - I don't think syrinx presence should be lumped in with "idiopathic." I don't get that. Moreover, I am not clear whether even if my kids had a diagnosis of Marfans whether the scoliosis diagnosis would change from AIS. I thing "collagenic" scoliosis is still within the "idiopathic" group as far as I can tell. That is my understanding from briefly talking to our surgeon by I certainly could be wrong... wouldn't be the first time and won't be the last.

We have been told that over time her vertebrae could wedge, but from what we know now, this is not the case. For those of you that have kids with scoliosis, have you been told that their vertebrae are wedged or deformed in some way?

I might email this question to our surgeon. I think wedging is likely best detected on the operating table by direct visual inspection. Linda will know.

[tonibunny]

My lumbar vertebrae grew progressively wedged over time, and this was clearly visible on x-rays. I suppose this was due to the uneven forces on the vertebral growth plates. The following x-ray is from when I was 16; check out L1 and L2:

http://farm3.static.flickr.com/2424/...d5b2a3e5_o.jpg


I wouldn't class scoliosis in the presence of a syrinx as idiopathic either!

[tonibunny]

I don't know I'm afraid Like you, I had always understood that a syrinx could cause a curve to happen by creating uneven force inside the spinal column (tumours can do the same thing) but I haven't actually read much about this subject.

I will try to find out more

[tonibunny]

That is interesting, and surprising that they didn't find a link! Hmmm, regarding the theories mentioned, vertebral anomalies that cause scoliosis are usually apparent from birth, and are classed as congenital scoliosis, and this doesn't explain why most cases of idiopathic scoliosis should mainly develop during adolescence - infantile growth spurts are just as intense, so if there were problems from birth I'd expect them to show up much sooner.

[Pooka1]

But, that doesn't really make sense.

Did I claim it made sense?

Take the SEAS patient. She seemed to have some fixed bony curve. When they braced her, she never braced past that curve. So, if even force couldn't correct her past that point, I'm guessing that's because that part of the curve is made up of bone.

OK, so they take the brace off, and she stays more or less stable for awhile and then, over the years, she progresses to her *pre-bracing curve*. Then, they intervene with exercise, and they're able to get her back to around where her curve was when she was braced.

So, the curve she had when she was braced, and the one the was able to regain with exercise, is likely a bony curve.

But the curve *before* she was braced, and the progression she saw *after* she was braced - that had to have been something other than bone. Otherwise, she wouldn't have been able to reverse it with exercise.

So, if all that is true, then, for someone like my son, how much of his curve is actually fixed in bone? He had his rapid progression after he stopped growing, and I suspect at least some of that was his muscles - he just seemed to collapse into the curve. Maybe that's similar to the SEAS woman, and he could get back to his pre-rapid progression curve (around 35 degrees).

Of course, this could all be fanciful and all 50 something degrees of his curve could be etched in bone.

I don't think we should assume this woman is typical. If her type of case were typical we would see SEAS publishing huge numbers of patients doing this rather than just one.

[Pooka1]

Well, here's an interesting study that I ran across looking up info on syrinx's (syrinxi? ) that comes back to our discussion about whether bones or muscles cause scoliosis:

" The exact link between syringomyelia and scoliosis is unknown. Is scoliosis a direct result of the presence of a syrinx? While this would seem to make sense, research - including this study - has failed to find a statistical link between syrinx size or location, and the type and severity of scoliosis, so perhaps syringomyelia and scoliosis are both the result of an abnormal spinal environment. Despite the research findings, there are several theories on how a syrinx can cause scoliosis. One theory proposes that the formation of a syrinx damages the motor neurons and results in an imbalance of the back muscles, making scoliosis more likely. Another theory proposes that when a fetus is developing, the presence of a syrinx will cause vertebra to form abnormally and lead to scoliosis. "

from - http://www.spinabifidasupport.com/sy..._scoliosis.htm

Even if it can be rigorously shown that some neural damage affects muscle adversely in some syrinx cases which then causes scoliosis, it does NOT then follow that exercise can halt or reverse any of that. Two different issues.

"Syrinxi" is pure genius, BTW.

[Pooka1]

Actually, I think I must be wrong about the bony part of the curve being the part you can't straighten with force. Surgeons aren't breaking bones when they straighten spines, and they can get something like a 0 degree correction on someone with a structural curve. So, what is the part that doesn't straighten with non-surgical force? Is it just ligaments?

No it is just a physical limit of the muscles. My girls went from 57*/58* to ~5*/0*. Therefore it was physically possible with external force and metal support. It was not physically possible with internal force (muscle).

And, here's another thought I had about gravity. Why is it that kyphosis rarely progresses in adults while scoliosis does? Shouldn't gravity work equally on both types of curves?

I think kyphosis progresses in adulthood.

[Pooka1]

(counting down to the time when McIntire comes on here to administer the dopes slaps to the bunnies... )

[Pooka1]

I agree that is a potentially relevant clue.

Note how they only claim delay as opposed to prevention. They seem to acknowledge that the stability will be lost when they stop exercising.

I hope they follow these women though time to document what happens if they do and don't exercise after the year.