WHILE LIFTING A 150 LB STEEL IMPACTOR HAMMER TO REPLACE BACK INTO THE STONE CRUSHER EE PULLED HIS RIGHT KNEE CAP. IT IS UNDETERMINED IF THIS IS A REPORTABLE INCIDENT DUE TO THE FACT HE LOST NO DUTY TIME AND DID NOT TAKE MEDICATION. HE DID NOT GO FOR MEDICAL TREATMENT UNTIL FRIDAY AFTER WORKING TWO FULL SHIFTS.