EMPLOYEE WAS DISLODGING A ROCK FROM A TAIL PULLEY WITH A BAR WHILE THE EQUIPMENT WAS SHUT OFF. AAS THE EE PUSHED ON THE BAR, IT SLIPPED WHEN THE ROCK BROKE FREE. THE EE'S HAND STRUCK THE METAL SCREEN/GUARD, WHICH PUNCTURED HIS HAND. THE EE RECIEVED APPROX 5 STITCHES OR SUTURES.