EE WAS DOING NORMAL JOB OF BAGGING & LOADING OF 50# BAGS OF VERMICULITE CONCENTRATE FOR A SHIPMENT ORDER. EARLY IN HIS SHIFT HE COMPLAINEDOF A SORE BACK. HE TOLD HIS SUPERVISOR, ASKING FOR HEL P. LATER IN THE SHIFT HIS BACK WAS VERY SORE. DR'S ANALYSIS STATED A SLIGHT STRAIN/SPRAIN OF THE LOWER BACK.