IIRC the thing that causes long term damage is staying in the same position for long periods of time. Without a back rest, there isn’t much movement you can do to change position. I could be misremembering though
Edit: of course you could just stand up every once in a while and that’d probably take care of it I guess, I’m not an Orthopedist
Wrists is what immediately jumped out at me, but a chair with no back support = no good long term
Isn’t it the exact opposite, as you are really forced to sit straight and don’t lean against the support?
IIRC the thing that causes long term damage is staying in the same position for long periods of time. Without a back rest, there isn’t much movement you can do to change position. I could be misremembering though
Edit: of course you could just stand up every once in a while and that’d probably take care of it I guess, I’m not an Orthopedist