ON 11/23/02 EE 3RD SHIFT ROOF BOLTER WORKED HIS SHIFT & LEFT THE JOB WITHOUT ANY COMPLAINT OF INJURY. THAT NIGHT HE CALLED IN TO SAY HE WAS UNABLE TO WORK DUE TO BACK PAIN. HE VISITED HIS FAMILY PHYSICIAN WHO DIAGNOSED HIM WITH MUSCLE STRAIN DUE TO REPETITIVE MOVEMENT.