Assessment context and image originals from this thread: https://www.reddit.com/r/AdvancedPosture/comments/1543wsi/rhomboid_glute_and_lower_back_pain/
Pretty common postural patterns seen many times before.
Feet placed in a wrong position. The blue lines (out steps) should be parallel and not converging at the back. You also tend to place your right foot ahead of your left - you load more wight on the right side in general.
Knees are slightly released. They would need to move beck to full extension.
Pelvis is rotated. Sacrum moving up (green dot) iliacs moving forward and down (blue dot at waist height). I've seen worse, but the rotation is there. It's indicated by the two lower white arrows. On this sideview, you could call it clockwise rotation.
Your ribcage rotates in exactly the opposite direction. That is anticlockwise. The top of your ribcage moves backwards, the bottom forwards - top white arrows. The yellow line, your sternum shows the rotation in the front. Your spine (the straight top big of the red curve shows it at the back. Your ribcage is in between.
These to rotations of the upper torso (ribcage) and lower torso (pelvis) have an effect on the highly articulated spine - your middle torso. The middle torso will take a shape depending on the rotations of the parts above (ribcage) and below (pelvis). Marked with a red curve.
To straighten the curve (yes, that's what you would want) you would need to flip the rotations of ribcage and pelvis.
The blue spots (ankles, knees, iliacs [anterior superior iliac spine], the bottom and top sternum) should all be on the green plumb line in order for your mechanism to function properly.
Think of yourself as a mechanism made up of parts (arms, legs, torso, head/neck). These parts (made of bones) move in relation to each other in order for the mechanism to perform certain function. For example, on the images you have moved in order to "stand". The way you have moved your parts of the body is habitual. You didn't really think of how you stood there. You just did, it was a subconscious affair. Something inside you (feelings / proprioception) told you that you are standing, and that is when you took the image.
The result is what we see.
The problem with this subconscious control is that you aren't really using the machine properly. That's why you have pain. So although you feel like you stand normally, you are in fact hurting yourself.
So the solution we use is a shift to "directed" movements. Basically, we first come up with a model of how the mechanism should work (just physics, mechanics, biology, geometry) and reason out what movements of each part of the body we would want (and which movements we dont' want). Then, we attempt to obtain such movements (or inhibit unwanted ones) regardless of what the feeling feedback is.
In your case, you would want to experiment with what happens if you swapped the rotations of the uppper and lower torso. According to my math, it would mean that the spine between would start lengthening. Which is what we want.
Yeah, everything you see is perfectly changeable and fixable. You don't have to live in pain if you move differently.
Let me know if you need more help with it.