EE COULD NOT SINGLE OUT A SPECIFIC INCIDENT THAT OCCURRED BUT FELT PAIN AFTER RIDING ON THE LOADER. EE HAD PRIOR BACK PROBLEMS IN 1999 & FELT THAT SOME BOUNCING ON THE LOADER MAY HAVE AGITATED HIS BACK. EE CAME IN TO WORK AT 3:00 & WORKED THROUGH ENTIRE SHIFT UNTIL 11:00 PM.