neck and shoulder
Bar risers can improve the ergonomics of your posture on the bike (think of how they tell you to set up your hands, seat and eyes when you are trying for good ergos in a chair looking at a computer!) It's kind of the same thing.
I have had shoulder and hand issues for a long time - the Strom was so smooth that I could ride farther without an issue than on other bikes. However, what I found helped me a lot was to STRETCH out my shoulders, arms, wrists, etc. before I started riding, and whenever I stopped. If I did this religiously it really helped with the cramping issues.