Yes, but as cynic stated there are a range of muscles involved. I just feel that those are one of the more important ones. Rhoms, lats, traps, erectors, etc all play a role.
I think there is a neanderthal no more article on tnation..
I just saw a guy a few weeks ago in school, a senior. He is muscular but his back like rounds into his neck. It's weird, he has horrible posture. Someone said that it might be when he is benching he uses his back or something? Prob wrong, but I thought it interesting.
Your glutes and abs will help - if you reduce the curvature of your lower spine, the upper will be reduced as well, thereby reducing the amount of slumping your shoulders do.
yeah, do you have a pelvic tilt aswell? IF you do, its because you got lazy long glutes and tight hip flextors on the front. So the hip flexors pull the pelvis down and the glutes are lazy and slack so they let it. You need to look into some glute activation and strenghtening the glutes.
If you activate them first by doing maybe some suprine (sp?) bridges and really squeeze the glutes so you make sure you use them, you will use them more if you do other movements that also includes the glutes. When you have lazy glutes its very typical that the hamstrings take over alot of the work the glutes should be doing, making them tight.
Back before I started working out I had a very weak back that would tier from just standing up, after doing a ****load of deadlifts, bent over rows, and so on, my back pain, weakness, and posture problems have all gone away....