These movements are common and heard quite often in yoga practices.
I had never really felt what it truly meant to accomplish this action before a few days ago. I examined what those specific movements would feel like and I have to say that it took loads of pressure off of my back. I hadn't realized how far I was leaning back in order to sustain the carriage of my baby.
I felt as if I went from leaning way back to standing straight backed. It was amazing. I guess it took being pregnant to feel what it is supposed to feel like when pressing the thighs back and pointing the tailbone down (or tucking it under).
I've been practicing it a lot throughout the day because I've been noticing/catching myself letting my back sink in quite a bit. It's like it has become my new mental note haha. Except I even catch myself correcting my posture while sitting as well.
I did that many times today while I was at school. If it was standing, I was telling myself "thighs back, tailbone down." And if I was sitting, it was more or less, "tuck tailbone and straighten back." My back is less of a mess today than it has been.
How come they don't tell pregnant women this more often in regards to their posture while pregnant? Obviously, there are benefits to performing yoga postures. Even one as simple as Tadasana to help alleviate back problems.
A woman I followed for a while through podcasting, Elsie Escobar, posted a link on her facebook page that actually relates to this. It is a video of Noah Maze going over the proper way of standing in Tadasana, Mountain Pose with Noah and Tara, and so it was nice to come across it as a reinforcement of proper alignment.
I find that this is most helpful to me when I'm being lazy, which tends to happen quite a bit while I'm doing homework. Most times I'll round my back or at others I'll slouch in general. Then I'll find that my back becomes sore and needs to be stretched out. As of late though, I've noticed less back pain (minus that which my pregnancy puts upon me).
Through these findings, I feel that it would be adequate to explore many more postures to see how they truly relate or help me in certain ways. More for my own understanding outside of books. It is one thing to read the ways it helps, and another thing to completely explore it.