Wednesday, January 10, 2007

:: Spinal Class ::

I started prenatal yoga yesterday at Yoga on High, a place I highly recommend already, even after just one day there. The class is 90 minutes long, which is pretty impressive, and there are 8 of us taking it. We ranged in "baby age" from one girl who is only 10 weeks pregnant to one woman who is 30 weeks pregnant. I fall in with two other women right around 15 and 16 weeks. I note all of this because one major reason I signed up for the class was to meet other pregnant ladies, particular those in the same boat as me. So that was a good part of class.

A weird part of class was that we hardly did any actual yoga. No poses, I mean. There was no downwarn-facing dog, no sun salutations, no mountain pose. What we got instead was a very interesting introduction to the human spine.

It is well known that pregnancy is hell on the back. From loosening joints like the SI joint (the mostly non-moving joint at the place where your hipbones meet your sacrum (see left: this is the part of your spine that meets your tailbone)) which can cause pain and discomfort to the added stress on back muscles (and thus vertebral joints) due to the added weight being carried out front, many pregnant women really suffer during the second half of their pregnancies.

So what we did in class was look at a moveable model of the human back. It looks very much like the picture I've included here. At the bottom of this picture is the tailbone and
sacrum (already referred to). The top of the sacrum is probably most noticeable to you as the place right above your butt where there is what feels like a wide bone. The lumbar spine (lumbar vertebrae) are right above this, and constitute your lower back. When you sit too long and have pain when you stand up, it's probably in your lumbar spine or the surrounding muscles. Near the top of the lumbar spine is where your waist is. That's about a quarter to a third of the way up your spine.

What we learned about in class (and saw demonstrated) was the difference between sitting in a way that you fold at your waist (the way many of us sit -- with our weight back on our sacrum and our hips rotated back) and sitting in a way that you fold at your hips (which is how you sit when you ride a road bike, for example: on your sit bones (actually the bottom of your hip bones)). When you slouch over at the computer like I am right now, you bend your spine above the lumbar spine, wrenching it all out of whack. The spine is flexible and can twist and bend, but it's not designed to withstand long-term bending in the middle like that. Especially down low there where the vertebrae are larger and thus have less movement. So much of what we did yesterday was learn to sit, stand, and bend in ways that crease at the hips rather than at the waist. It's easy at first but habit makes it hard to maintain -- we're just so used to sitting badly!

The other really interesting thing we learned as about the vertebrae themselves. Look up at that picture. See how the vertebrae are nice and thick on the inside (the part facing the internal organs, here the part facing to the left) and thinner and sort of knobbier on the outside (the part that makes those bumps on our backs)? Those inside parts, the thicker ones, are designed to bear weight. They're cushioned more on that side, too. The outside parts, the knobbier parts, are designed to protect the spinal cord, not to bear our constant weight. Yet, when we overarch our backs and necks, we are putting our weight on those parts instead of on the nice strong, stable parts. This also leads to pain, like that nagging neck pain you get or, if you're like me and Brian, the pain you get in the muscles along your shoulder blades and the upper part of your spine. We are taught from childhood that good posture means holding our shoulders back, arching our lower backs, and holding our heads up. But this puts undue pressure on the wrong parts of the vertebrae.

Here's the cool part. Picture your spine as you're sitting here reading. Now sit forward on your sit bones (you may really feel like you're leaning forward) and imagine trying to stack yourself up on the strong parts of your vertebrae. You may feel like you're "slouching" but a look in a mirror would reveal that you're not. You're just conditioned to want to arch backwards. But don't you feel better? Now stop holding in your stomach muscles. Just let them relax. I don't know about you, but my back muscles immediately lose tension and any discomfort or pain.

Cool, huh? We also learned good sleeping posture. The sleeping thing I tried last night and it worked. No neck pain when I woke up. But the sitting thing is going to take a lot of practice because I have so many years of habit to break (not to mention all those years of gymnastics, where posture is even more exaggerated).