In the past two months, I ahve had two instances of severe neck/shoudler pain. The first time, it lasted for an agonizing week before going away, the second time, for a few days.
I have not done anything (sports, otherwise) that could irritate that region. I do, however, have cracking when I move my neck, as well as the 'sand' sound and sensation.
The second time, which was a few days ago... it went away, and then my left upper arm began to hurt. A pulsing, burning sensation in the muscle, as well as ocassional tingling in the fingers. Depending on how I have my arm, the pain will diminish to very low, or become very bad.
A few friends of mine say it is stress, as every time it comes up I seem to have a driver's exam, or something bad happens.
Also, I have been using a PC for 10 years, and I am an analyst right now.