Besides getting a good ergonomic keyboard and taking frequent breaks like other comments mentioned here, moderate strength training exercise is a must. I gave up strength training and focused on just running for the last 3 years. Running was the only exercise I did. I was in shape and had good general health but my neck and shoulder and back really bothered me. My family doctor suggested that I incorporate strength training into my routine. So, I bought a few dumbbells and a bench for my home gym. I haven’t had a stiff neck or sore shoulders, back for a couple of months now (knocking on wood). I hope this is the cure for our profession.