Your butt, the big gluteus maximus muscle is designed to do nothing while you are standing still. It doesn’t even do very much in walking only getting in the game when going up a hill or up stairs. And you are using it extensively if you are into the gym and doing lots of squats and extension exercises when you are working out.
But when you are standing you must learn to let it go.
It is my first and most important instruction. We are a tight assed people and we must learn to let go of our butts. The payoff is extreme in its benefit. Energetically the main nerves connecting the brain to our legs pass deep to our gluteal muscles. If the big gluteus maximus is tight it usually forces all of its underlying muscles into dysfunction. The include gluteus medius, minimus, and especially the piriformis muscle which lies on top of the sciatic nerve, the longest nerve in the body which supply’s a great deal of energy to the legs.
Relax your butt and allow other pelvic muscles to find a happier home. Relax your butt and the nerves will follow providing greater energy to the lower limbs. Relax your butt and your spine might be able to sit more easily on top of your pelvis. A tight butt pulls down in the back of the pelvis pulling it into a tuck and flattening the lower back.
In general it’s better to be soft than hard. When you are standing up and your pelvis is in the right position your butt lets go naturally. This is the beautiful thing about good posture and alignment. Aligning the bones usually frees the muscles to do their work as designed. To get your pelvis into the right position when standing, feel what your butt is doing when you think you are standing up straight. Then tilt the top of your pelvis very slightly forward sticking your butt out a tiny bit. Feel what happens to your gluteus maximus. If you can, rotate your pelvis forward and back feeling what it does to your big butt muscle. Find the place where the butt is most relaxed.
I think that this is the proper position of the pelvis and you would like to work on maintaining that alignment as best you can. It isn’t necessarily easy just because you know it might be right and you want to do it. There are numerous tight muscles that will work to prevent you from changing your posture. Those muscles and more ways to feel the proper position of the pelvis are coming soon.