EE WAS DRILLING A HOLE WITH A JACKHAMMER ROCK DRILL WHEN IT BECAME STUCK. HE TRIED TO PULL THE DRILL FREE AND HAD TO ""PULL HARDER"". HE FELT A SHARP PAIN IN HIS BACK. HE ADMITTED TO LIFTING WITH HIS BACK AND NOT HIS LEGS. HE SUFFERED A PULLED MUSCLE IN HIS BIDDLE BACK.