Ways I've tried sitting at the computer

I have tried various ways to sit at the computer (with the chin and shoulders up) and I think I have found the best way. Here were the ways I tried in order:

No chair or stool with computer trackpad for about 3 months -this made me rather listless in reading books I found to be important. Somewhat surprisingly, it was somewhat better than the next four ways.

Stool -worked great at first, but then resulted in listlessness and low back pain after about 2 months. This was when I tried using a stylus with the trackpad, but I abandoned this idea due to its impracticality.

Chair with two foot high vertical metal bars in the back (for about a month) -didn’t work at improving productivity.

Chair with a metal back rest set 135 degrees back -tried this for two weeks; did not improve productivity.

Office chair (for about six months) -improved productivity at first, but then resulted in pain in my lower back muscles when I tried to finish a book on the computer. Probably the worst way to sit.

Stool (again) -same result as last time, though I clearly had more productivity with it than with the office chair.

IKEA wooden chair with a horizontal wooden strip as a low back rest -worked for 12 days; resulted in me finishing one book, but no more.

Wooden chair (with two foot high solid vertical back rest set at about 100 degrees) -so far, the best result for me; makes reading and learning languages very easy (though typing is still rather difficult).