I went to the Healthy Back Store near my home and bought a Kneeling Chair Plus. It makes you sit up straight, just like your mother told you to. I figure that I spend more time sitting in front of my computer at home that I do practicing on the mat so it’s probably a wise purchase. I’ve been slumping over a keyboard for 20 years, and throw in another 10 years if you want to include typewriters. Then add the years that I’ve been slumped back in a chair reading. No wonder my core muscles are weak.
At my age, you’re not going to reverse aging and bad posture by fiat. It comes from small, modest increments.