EMPLOYEE WAS USING A LARGE PRIZE BAR TO FORCE A TAIL PULLEY FROM UNDER A FRAME. THE BELT THE TWOEMPLOYEES WERE WORKING ON WAS ALREADY TENSIONED BY TWO CHAIN JACKS. WHEN THE PULLEY DISLODGED FROM THE FRAME THE FORCE PUSHED THE BAR BACK STRIKING THE EMPLOYEE ON THE RIGHT FOREHEAD. HE WAS GIVEN PROFESSIONAL MEDICAL ATTENTION THAT REQUIRED TEN STITCHES.