EE ALLEDGES THAT WHILE INSTALLING A CYLINDER ON A LOADER, HE WAS HITTING A PIN WITH A SLEDGEHAMMER WHILE IN AN AWKWARD POSITION CAUSING HIM TO STRAIN HIS LOWER BACK. EE DID NOT INDICATE TO THE MINE THERE WAS AN INJURY UNTIL 3/9/03. EE DID NOT FILL OUT AN ACCIDENT REPORT UNTIL 3/14/03.