EE WAS USING A RATCHET AND A SOCKET TO LOOSEN BOLTS THAT WERE BADLY CORRODED. AS HE PULLED ON THE RATCHET, HE FELT SOMETHING ""POP"" IN HIS SHOULDER. THERE WAS NO DAMAGE TO EQUIPMENT OR THE MINI NG OPERATION. EE NEEDED TO USE A BREAKER BAR TO LOOSEN THE BOLTS. NO OTHER FACTORS WERE INVOLVED.