[hundredwatt]

I had the same problem. In addition to regular exercise, try doing these stretches for once or twice a day: https://www.youtube.com/watch?v=FdNS95hpL-o (they are fun too! Perhaps get a group together at your office to stretch together once a day)

These exercises work to move your body back toward perfect posture, undoing the damage caused by sitting, typing, etc.

I stopped using these in November due to travel. My back and shoulder pain returned. It took about 7 days of consistent stretching for the pain to go away again.