USING SLATE BAR TO PRY CINDER BLOCKS DOWN THAT WAS LEFT FROM A FALLEN STOPPING. HAD BAR OVERHEAD PRYING AND FELT PAIN IN LOWER BACK AND RECTUM. STRAINED LOWER LUMBAR. WAS TOLD THAT EMPLOYEE HA D A MEDICAL PROBLEM FIRST (HEMORRHOIDS) BUT LATER FOUND OUT ABOUT STRAINED LOWER LUMBAR ON 3-01-2004.