John Paulsen: The Ergohuman chair, made by Raynor, is a midpriced chair, that has all of the required features of an ergonomic chair. I’ll go through all those features, and show you how I like to adjust my chair.
First of all, what you want to do, is stand facing the chair, and the seat pan height should be about the same height as just below your kneecaps. Stand by the chair, and then lower it until it’s about at kneecap height. Now, when you sit in it, feet should be at about floor level, or should be flat on the floor. Now you’re going to adjust the seat pan depth, and you can make any final adjustments to the seat height too. As far as the seat slide goes, you want the seat to come within about a clenched fist from the back of your knee. So, hold a clenched fist in there, and then you can slide the seat slide forward, and then lock it in place. So, when you’re sitting back, you can reach down and put a closed, clenched fist in between there. You don’t want any pressure between the front of your seat and the back of your knee, because that can cause sciatic nerve problems.
Next, you’re going to want to adjust the lumbar support, and the Ergohuman chair has the seat slide or the backslide here, so I can go up and down with that. I want it to fit right in the orthotic curve of my back, so right in the natural curve in the back. As far as armrest height, you want your armrest so your arms are comfortable at your side, and slightly supported, to take the weight off your upper back. The final adjustment you can do is with the headrest; it slides up and down, and allows you to rest your neck as you’re working. It will relieve a little stress from your neck, too. This chair allows you to tilt; it also has a lock, so I can lock it in place. I can lock it all the way forward, or I can lock it in various positions as I go back, or go full recline. If you go full recline, your feet may come slightly off the floor, so you’ll want to lower the seat just slightly and keep your feet on the floor.
Now, with my chair properly adjusted, what we want is to move to the keyboard tray. You want your keyboard pretty much right down in your lap; this is to allow your forearms to be at a slight negative angle, down to the keyboard, and you also want your keyboard to be at a slight negative angle, going away from you. This ensures that your wrists are straight, and you don’t have the flexion in your wrist. You want your mouse as close as possible as well, to get it right next to your keyboard; you don’t want to be reaching out for your mouse. You want your monitor at about eye height or just below, and you want to be able to reach out and be about an arm’s length away from the screen. That’s an ergonomic position; we can work like this, or if you’d like, to relieve a little stress on your back, you can recline a bit and support your head on the headrest and work like this.