I post this alignment thought not because I’m an expert or because I even know if it’s a common issue, but because it’s one that I do myself. Also, it relates to the psoas muscles, and aren’t things nifty when they follow a theme?
Some relevant physical background: I have a very bendy lower back as well as psoas muscles that have some tightness. By “have some tightness,” I mean that while I don’t know they compare to other’s psoas muscles (psoases?), I do know that they are sometimes the muscles that keep me from deepening a pose. I also have an anterior pelvic tilt and chronic pelvic pain. It’s plausible that tight psoas muscles might be contributing to one or both of those, but it’s impossible to say for sure right now.
In paying attention to my psoas muscles, I’ve started focusing on my pelvic alignment in my standing postures — particularly forward-facing standing postures like high lunge and warrior I. For a long time — years, probably — I’ve been letting my pelvis tip forward in these poses so that my tailbone points more toward the back wall than it does toward the floor:
Compare this to a low lunge where I made a conscious effort to lengthen my tailbone toward the ground. The angle isn’t perfectly perpendicular, but there’s a noticeable difference from the first picture:
For the record, it’s the same in warrior I — a pose that’s probably more relevant because I spend more time there — but I didn’t have a good set of comparison pics on file.
Because of the flexibility in my low back, letting my lumbar spine carry the poses has been the path of least resistance for me. Which is not always a bad thing but in this case meant I was not having as awesome an experience in warrior I and high lunge as I could. To be clear, even though this is a distinct possibility for some people, I never found overbending to be painful or uncomfortable here. So what, exactly, is the big deal?
The big deal, at least to me, is that I’m missing out on growth in the pose. If I tread the path of least resistance, doing what my body does comfortably anyway, I’m stretching the muscles that are already flexible and strengthening the muscles that are already strong. And I’m doing so at the expense of strengthening the muscles that are weak and stretching the muscles that are tight.
Because when I do try warrior I with my tailbone lengthening down, my pelvis in a neutral tilt, and my back leg as the primary anchor of the pose — there is some bodily change going on there, let me tell you. The psoas on my extended leg is stretching, maybe not super intensely, but quite enough that I can feel it. And on that same back leg, because I’m pressing into it so strongly, there is some kind of muscle on the outside of my hip — maybe my gluteus medius — that is working hard to stabilize my whole body in the pose. On the whole, it’s more freeing and more rewarding to feel like I’m making a difference to my body.
In this case, at this time, it does not serve my body or my practice to follow the path of least resistance.