This chair is rated for all day but by the end of the day by legs and behind hurt. I think I am too tall for the chair as my knees stick out very far. This is what I think is causing the issue. Either I'm too tall (5'8") or the seat is too short.
the head rest has to be removed because it pushes on my shoulders when im sitting upright but it is comfortable when leaning back and resting head. although the headrest can be adjusted by sliding up and down also can be tilted it still touches top of my shoulders and is annoying. i can probably put plastic spacers between headrest mount and chair but will need to buy longer mount screws as well.