MOTOR MECHANIC, EE WAS CHANGING THE REAR DOOR SEAL ON THE VAC TRUCK ON 3/27/03, AND REPORTED PAIN IN HIS RIGHT SHOULDER TRYING TO FORCE THE SEAL IN PLACE. HE HAS BEEN WORKING THRU THE DISCOMF ORT WITH 1ST AID AND PERSONAL MEASURES, UNTIL 11/7/03 WHEN MEDICAL TREATMENT BECAME NECESSARY, WITH PT, AND RESTRICTED OVERHEAD USE OF RIGHT ARM TEMPORARILY. THIS BECAME A REPETITIVE OVEREXER