ROCK STRUCK EE WHEN LOADER OPERATOR DROPPED LOAD INTO FEEDER. EXCESS ROCK WENT OVER FEED WALL WHILE EE WAS DOING DAILY GREASING. INITIAL RESULTS WERE FOR EE TO RETURN TO WORK FULL DUTY. ON 4/29/03, EE HAD NOT IMPROVED. FOLLOW-UP MEDICAL TREATMENT PRESCRIBED MEDICATION AND TIME OFF WORK.