As Dennis says: "You occupation/hobby etc. Have no bearing on the onset or progression of the complaint." But, I do feel that the arthritis I have in the base of my right thumb, which is larger than my left, probably comes from over-using the thumb while playing an awful lot of clawhammer banjo. Most doctors that I have spoken to regarding my own Dupuytrens Contacture agree that it is generic and nothing to do with occupation.