When using a keyboard or mouse for a long time, you may experience occasional discomfort in your hands, arms, shoulders, neck, or other part of body, please follow the advice as below.
1. Get out of your computer several time in one hour.
2. Change your habit of the operation.
3. Get away from the mouse to relax your hands, arms.
4. Simplify the operation when you work.
I can't tell you how important #1 is. It is extremely hot and dry inside a computer, so if you don't take water breaks, you could get heatstroke and die. ::nod::