EE WAS WORKING IN A DITCH PREPARING FOOTING FOR DOWN PIPE SPOUTS. HE LOOKED UP AND STEPPED BACK AND HIS FOOT SLIPPED ON SOME EXISTING PIPES IN THE DITCH CAUSING HIM TO FALL. HE SAID HE FELT SLIGHT PULL IN HIS LEFT SHOULDER & RIGHT SIDE OF HIS LOWER BACK. AT THE TIME HE FELT HE WOULD BE OK. HE BROUGHT THIS TO OUR ATTENTION AGAIN ON 4/6/05. WE SENT HIM TO OUT PANEL PHYSICIAN.