EE's shoulder became sore throughout the day while changing a balling feed screen on 4/21/08. This was initially a no treatment case, but the EE began receiving physical therapy on 6/12/08. *Per Dr's notes, this is an on-going problem for employee. MRI indicate Arthritic changes of the joint. Symptoms & pain were evident 7-8 months prior & not related to activites of 4/21/08.*