Maria Teresa Borges de Almeida wrote:

If there’s one thing that was constantly screamed at me when I was a young girl, it was to sit up straight and have a good posture. It didn’t matter where it was, you just had to sit upright and avoid slouching. There’s no one now standing behind me to remind to stop slouching but that good habit has stayed with me. That being said, this is what I do:

1. I sit well back in my ergonomic chair with a tall back and arm rests,
2. For lumbar support I bought a small cushion (Orthia) (https://www.orthia.eu/en/loja/comfort-and-well-being/support-pillows/lumbar-support/),
3. I have adjusted the seat height so that my feet are flat on the floor and my knees are equal to, or slightly lower, than my hips,
4. My screen is at eye level, the height of my keyboard is adjusted, as well as my lamps,
5. I have all objects I need within easy reach,
6. I take 2-3 minutes breaks (almost) every hour to stretch and walk,
7. I do physio 3 times a week (I had a knee prosthesis to replace a joint damaged by osteoarthritis)

I must be doing something right as I'm old and do not suffer from any of the common ailments generally attributed to sitting at the computer…