I have a Prostate problem that was directly attributed to the chairs I sat in, in school. ,The doctor gave me a foam pad that relieved the problem,
but the damage is still there. This was 40 years ago.
Sometimes my tailbone would go numb but that was about it. I read somewhere that the harder the chair the better the body support. The cubby hole in
the desk was great for hiding the sunflower seed husks in while sneaking a snack during class.