i had the same problem in my shoulder with they ribing of the bones. 2 important thinks need to be done, that dude needs to be taking calcium any kind is fine but i personally think coral cancium is better. and he needs to take Sea Salt preferably celtic Sea Salt if posable. and third he need to take MSM for the inflamtion, pain and to help it heal its self. i hope you take my advise and research it because i not have no rubbing of my shoulder bone, al least that i can feel because before i could feel it and sometimes hear it, it would crack