Problem: Bad back
Bad sitting and working postures can cause back and neck aches to occur. Constant sitting in one position is harmful, but unfortunately this is a necessary evil in our profession.
The soft discs between vertebrae dry over time, and these discs can put pressure on nerves, inflicting great pain. Aside from constant breaks and walking around as much as possible, here are some other things to try.
SOLUTIONS
Deadlifts - many of my friends who are in the business complain about wrist and back problems all the time. None of them regularly do deadlifts. Deadlifts are a classic exercise where you bend over and pick up a weight, using your forearm/wrist and posterior chain muscles. Here's a book with good explanations on deadlift form. Start off light, perhaps once a week, and ensure that you have someone watching your form to ensure you're doing it properly.
Yoga - Yoga helps your muscles relax so you can be more resilient. I highly recommend simply going on Youtube, getting a mat, and following some routines-- your body will thank you. Note that the harder poses take a while to build up to, so be patient!