I sit on a IKEA barstool without cushioning behind a jury rigged standing desk. Actually solved my back pain that I got from an office chair. Probably because I’m forced to sit more at the front of the chair since it’s hard to push the chair close to the desk once I’m sitting on it. I can’t lean back, so my back is straight.

I’m of the opinion that using a really good comfy chair everyday for 8 hours that relaxes your body is probably not good for you in the long run. It makes your body weak. It’s like sitting on a sofa all day.

I know people that sit on the floor all day on a sturdy cushion in a lotus position behind a coffee table they use as a desk. They never have pain in their back or anywhere else. If you can sit with your back straight and your hips are at 90+ degrees angle so your knees are below your hips you will reduce the chances of getting issues with your back significantly and it doesn’t really matter what kind of chair you use.