EMPLOYEE WAS BUILDING A PERMANENT STOPPING OUT OF 6"" HOLLOW CEMENT BLOCKS. HE WAS USING A MASONRY HAMMER TO CUT A 6"" BLOCK. HIS RIGHT ARM & SHOULDER STARTED TO HURT. THERE WAS NO DAMAGE OR IMP AIRMENT TO THE OPERATOR OR TO ANY EQUIPMENT. IMPROPER USE OF HAMMER CAUSED INJURY. THERE WERE NO OTHER FACTORS INVOLVED.