Well, Pete Egoscue (pronounced Ee-GAW-scue) would have something to say about this. He says that poor posture causes pain, pain, and more PAIN. All over the body. Due to recurring hip and neck pain lately, I've gone back to my Egoscue exercises. I've been at it for a couple of weeks now, and I'm already noticing a difference. Here is a picture of me today:
Notice that my right shoulder is slightly lower than my left shoulder, making my right arm appear a bit longer. My right hip is slightly elevated. My head is slightly tipped to the left. These are the things I'm working on from the front view. I'm assuming that my head tilt is due to compensating for the lowered right shoulder. The shoulder/hip misalignment is definitely part of the cause of the neck pain. I must say, though, that a year ago when I was doing these exercises in earnest, my misalignment was much more noticeable. My feet are pointing more or less straight ahead now, and that is an improvement. My right foot used to splay outward somewhat, which was tweeking my hip and giving me serious groin pain. The pain is much less now. I believe I'm making progress!
Here is my current profile:
This, again, is much improved from before. I used to lean forward quite a bit more than this so my center of gravity was over my toes, believe it or not. I think it was partly because I had such a dramatic neck jut that the weight of my head (about 10 pounds) was pulling me forward. I still need to move my head back more. This will help eliminate the leaning and also decrease the sway back. It takes a lot of muscles, constantly contracting, to counterbalance a head that feels like it's falling to the ground! And that equals PAIN.
So this is my update. I expect that in six months my posture should be nearly perfect. It takes a while to undo 40 years of bad posture. But, pain is the great motivator!