Don't! lol!!!
My lower back/hip had been aching like crazy, and finally went to the chiropractor (sp?) yesterday. (we just got health insurance again! Yay!! :) )
He did 3 or 4 adjustments, as he said my pelvic was out a bit. ~ From always sitting with my right foot tucked under me! Apparently it messes with your pelvic/hip socket? I go back again Thursday morning.
He suggested I use a small box, etc as like a footstool, when on the computer or sewing. It is very hard for me to just sit flat on my butt!! And not tucking one's foot is a very hard habit to break I'm discovering! lol!!!
I posted on Facebook about this, and several said "I do that too!" So I thought I'd let you all know what I found out. :-)