There are no good ways to sit. No matter how beautiful you sit, you are going to put at least one-third more pressure on your spine than when you are standing up or lying down. No matter your poise, sitting for more than ten minutes is going to do you harm. It will deform your kinesthetic sense.
There is no comfortable way to sit for longer than a few minutes. There is no good chair. See Galen Cranz’s book for more info.
The best person for figuring out your sitting situation and your overall office ergonomics is USC instructor Babette Markus.
But there are worse ways and better ways to sit as the following explains:
Alexander technique instructor Matt Pressman says most people sit all wrong, collapsing the spine into a C-curve, rotating onto their tailbone and counterbalancing by pushing their head forward. This posture effectively doubles the weight of the head, putting nearly 20 extra pounds of pressure on the spine. He offers these tips on how to sit correctly using the Alexander technique:
Step 1. Sit on a hard chair and slide your hands, palms up, between the seat of your chair and your bottom. Your palms will feel two, sharp bony structures, your so-called “sitz bones.”
Step 2. Back your bottom all the way toward the back of the chair, balance lightly on your sitz bones, and lean back, easing the back of your torso into the back of your chair. Let the back of the chair absorb the weight of your torso.