Even when you have an ergonomically sound workstation, you need to do more for prevention. Some precautions on your part will help prevent strain and/or overuse syndromes. There is something very simple you can do to help prevent overuse: just take a break! It’s that simple, and your computer can even help you do it!
I hear you saying that you just get engrossed in what you are doing and “forget”. That is no excuse–your computer can help you! There are a number of programs available that will remind you to take a break; some of those are even free! Others that are available for a moderate cost will allow more customization optimization to fit how you work, when and how often to remind you that you need to take a break. Some will even give you preventative stretching exercises to do during the breaks.
I feel that I can lecture on prevention because I didn’t do it until after the symptoms of carpal tunnel and Guyon canal compression had set in. After having had hand surgery twice, I had to do recovery which is so much more painful, so much harder and longer than prevention would have been.
What is a “good” break? It’s not the one you take when you are already in pain. It’s a break that you take to prevent pain from occurring.