A few key stretches throughout the day can keep us limber and refreshed. This manual of exercises for office workers is great for people like us who are prone to never moving anything but our fingers for eight hours straight.
Provided by Comcare, an Australian government workplace health organisation, the PDF document (actually part of a larger manual for occupational safety) includes basic but essential stretches you should do whenever you can take a break: neck rolls, wrist and elbow stretches, eye exercises and so on. Download the instructions via the link below and post it on your corkboard or somewhere to remind you to get moving now and then.
For your convenience, here are the illustrations in one graphic (click to enlarge or right-click to save):
If you have four minutes, you might want to try some desk yoga too.
Exercises for Office Workers (PDF) [Deakin University Australia]