EMPLOYEE WAS ATTEMPTING TO REMOVE A BLOWN HYDRAULIC HOSE. HE WAS REMOVING A STAPLE USING TWO LONGWALL HAMMERS. THE PICK END OF ONE HAMMER WAS INSERTED UNDER THE STAPLE AND THE OTHER WAS USED TO DRIVE THE PICK AND LIFT THE STAPLE. WHILE HAMMERING, THE EMPLOYEE STRUCK HIS LEFT THUMB CAUSING A LACERATION. SEVEN STITCHES WERE REQUIRED TO CLOSE LACERATION.