Ergonomics+-+how+to+sit+-+stay...

Here it's written by much more eloquant people than me.
http://www.swinburne.edu.au/corporate/hr/ohs/ohs_ergonomics.htm

Raise/lower the seat to enable the desk height to be at your elbow height. If you are a �touch typist�, you may sit slightly higher. Adjust chair height so the feet are comfortably flat on the floor, the thighs are approximately horizontal and the lower legs approximately vertical. Set to horizontal initially, although you may wish to adjust the tilt slightly forward to suit your comfort. || || Move the backrest to locate the lumbar support to the curve of your lower back. Lock the backrest into place. Use your body weight to lean back against the backrest. Depress the control lever to enable the back rest to change the angle. Frequent posture changes encourages blood flow to different muscle groups which helps minimize back fatigue when sitting for prolonged periods. || || Armrests are usually not recommended unless they are well out of the way of the desk. However, if your chair has arm rests make sure that they do not prevent you from getting as close to the desk as you require or that they impinge on your elbows while you are working Use a foot rest if you feel pressure under your thighs from the front edge of your seat. A foot rest is also useful to address lower back fatigue when sitting for long periods. Pushing your feet into the foot rest helps to push your back into the angled back rest of the chair. || ||
 * ~ ==YOUR WORKSTATION - THE CHAIR== ||
 * SEAT:**
 * Height:**
 * Height:**
 * Tilt (if available)**
 * BACK REST:**
 * Height:**
 * Height:**
 * Angle:**
 * ARM RESTS:**
 * ARM RESTS:**
 * FOOT RESTS:**
 * ^  || [[image:http://www.swinburne.edu.au/corporate/hr/ohs/images/ergo_chair_4.gif width="151" height="152" align="right" caption="figure 4"]] ||