DUMPING CLEANED UP MATERIAL FROM 55 GAL DRUMS INTO DUMPSTER. MINER WAS STEADYING BARREL WITH LEFT HAND WHEN HE HEARD A POP IN HIS SHOULDER. THE FOLLOWING DAY, SHOULDER WAS PAINFUL SO TREATMENT WAS SOUGHT. WAS GIVEN SLING TO WEAR UP TO 48 HOURS, THEN INCRREASE IN RANGE OF MOTION IS ADVISED. NO OPERATION OF MOVING EQUIPMENT OR OVERHEAD LIFTING FOR 7 DAYS.