I have been getting a severe ache/cramp in along the top of left shoulder every time I do a long run in the past few months. I had put it down to bad posture whilst seated at my desk at work, but even changing that hasn't helped. I'm getting sports massage treatment for my shoulders, neck and upper back which seems to be only a temporary resolution.
Nothing I seem to do stops the aching reappearing, I just have to run through it. I find that holding my arm extended at shoulder level and turning my head to look to the right gets a stretch along the area, but obviously you can hold this for a few seconds whilst running, to avoid trees and people etc.
I would be very interested to hear if anyone has come up with a method which prevents these aches and pains occuring, it's worse than blisters, stitches and shin splints all at the same time! Help!