EMPLOYEE WAS USING A STONE BAR TO SLOW DOWN THE SPIN OF A SPOOL OF HIGH VOLTAGE CABLE THAT WAS SUSPENDED FROM THE MINE ROOF AS THE CABLE WAS BEING PULLED FROM IT. THE CHAIN CAME LOOSE, CAUSING THE SPOOL OF CABLE TO FALL AND KNOCKED THE BAR OUT OF HIS HANDS STRIKING HIM ON TOP OF THE RIGHT FOOT. THIS OCCURRED IN THE #1 BELT ENTRY F-8 SECTION.