Top of screen at eye level? I'm not sure this scales well with large monitors.
It is ideal so your eyes can just look straight ahead or down, and doesn't involve head/neck movement. Mostly this is to show people that a laptop screen down on a desk is too much downward neck strain. And most people have their monitor too low. Those giant monitors do pose a problem because height off of desk may put top of monitor too high. Tilting head up to view a screen becomes neck strain. Probably best to size monitors to the task, and not jump right to a huge 4k, that you then need to scale up all the fonts to be able to read anything.
That doesn’t make sense. First you say to look down then say looking down is too much strain. I think it would make more sense to position the center of your monitor at eye level so you don’t need to always look down or always up. Plus the content is viewed in the center of the screen, not at the top.
Random other info:
- a headrest is unnecessary for the purposes of sitting correctly in an office chair. Headrests tend to put your cervical spine into slight extension if you're sitting straight up.
- one thing you can't see from this angle is your shoulder abduction angle. Most office chairs are quite wide, so trying to use the armrests while you type can put an unnecessary amount of strain on your wrists. Ideal positioning for your elbows is directly below your shoulders, like where they would rest if you were standing up. Better for your shoulders and wrists.
- if you're looking for a good ergo chair, I always recommend a used/refurbished higher end chair rather than a cheaper new chair. The higher end chairs (Steelcase, Humanscale, Herman Miller, Autonomous, etc) typically have replaceable parts and sometimes will still have a manufacturer's warranty depending on where you buy it.
I'm a kinesiologist who has done a lot of office ergo work.
"sitting passively with a stacked spine is really bad over long periods" -- my physio
"You should sit straight up for your 996 job" -- these infographics with all the validity of a food pyramid.
