When sitting one the ground I always sit on my knees (Seiza), because when I try to sit on my buttocks I tend to lie down, and it's just very exhausting for me to sit this way.
So when I sit on a chair, I'm guilty of heavy slouching when I sit on my ass. When I let go, or don't concentrate on it, sometimes my back touches the lower part of the chair, because I just slouch so heavily. I don't have back problems, because I'm very careful when I crouch or lift heavy objects, but when I sit, I don't want to concentrate on sitting, but rather on my work.
One solution for me was to sit on one leg on the chair and have the other one either hanging or sort of pursed in to the chair. I can feel that my back is straight when I sit this way, but I always wonder if I commit some atrocity to my legs (esp. knees) whenever I do this.
So are there some health drawbacks to sitting this way? (Also I don't really know how to tag this...)