WHILE PRE-SHIFTING THE BELT THE EE LEFT FOOT CAUGHT IN THE MUD CAUSING HIM TO FALL. HE FELT PAININ THE BACK OF HIS KNEE. EX-RAYS WERE NEGATIVE AND THE EE RETURNED TO WORK THE NEXT SHIFT. ON 5-5-03 THE EE RE AGGRAVATED THE KNEE IN THE BOAT HOUSE. MRI ADVISED.