http://purelocal.com/Video.aspx?videoid=1x3lKmx3iWg&slk=causes+of+pain+in+upper+arm&cid=10264318258&kwid=21122313488&akwd=causes+of+pain+in+upper+arm&uq=arm+joint+pain+when+running+livestrong&nid=2&term=causes+of+pain+in+upper+arm&vx=0
Which joint? The elbow? The shoulder? Does this joint hurt any other time, such as when you lift weights or if you don't do that when you lift something heavy? Running is a lot of pounding, and things that are hurt will show themselves.