Zone 1 - Prevent back tension
Check your posture. A back and foot support may help achieve the best working position.
Zone 2 - Avoid wrist pressure
Support your wrists. Keep forearms parallel with the top of your desk and wrist in a fairly neutral position.
Zone 3 - Relieve neck strain
Achieve comfortable viewing. Ensure your eyes are in line with the top of your screen.
Zone 4 - Reduce inactivity
Introduce movement. Regular changes to your working position helps you work better and feel better.