I want to sit on the floor but it causes my low back to round. I can feel the vertebrae sticking out and it's fully rounded. I can't straighten it because it feels like my hamstrings are too tight to allow my pelvis to tilt to 90 or better. It's stuck tilted slightly backward.
When I'm standing, my pelvis is slightly tilted forward like it should be and my low back is in good position.
So should I be able to get normal pelvic tilt while sitting on the floor (in any position, including legs out straight) and does this mean my hamstrings are too tight and I should stretch them?