EE ALLEGED THAT WHILE BEING LOADED WITH BOULDERS THE LOADER OPERATOR DUMPED THE ROCKS TO HARD CAUSING THE TRUCK TO SHAKE AND INJURING THE EE'S BACK. THIS INCIDENT HAPPENED ON 10-23-03 SHIFT BU T HAPPENED ON THE 10-24-03. THE EE DID NOT REPORT THIS INCIDENT TIL THE NEXT DAY. EE WAS TAKEN TO LOCAL HOSPITAL, EE WAS BUT ON TWO DAYS OF RESTRICTED DUTY.