Just search it on the internet. Because for me, ergonomic problems only occurs because of bad habits like slouching when you use your computer.
I agree, even you have the most ergonomic chair that is created, if you have a poor habits, then it wouldn't make sense.
I also think the same, because a chair by very ergonomic can not correct bad habits, it is best to choose to have the best position to be completely straight on the back and upright, thus avoid discomfort.