1. No, I haven kno anyone ever suffered from RSI or SAD
2. Yes, when I use a computer for a long periods of time I have pains in my back because I don sit correctly.
3. When you use a computer for a long period of time you should take a rest like, stand up and walk, put you hands over you head, try to sit correctly, bend your head to the left towards you shpulders.
4. Yes, I think the excercises are very useful and effective because help to relax and rest your body.
5. Yes, I do some excercise while working for a long period of time. I srand up and walk, down stairs and rise my arms.