EMPLOYEE REPORTED: HELPING SECTION REPAIRMAN MAKE REPAIRS TO RAM CAR. WHEN ATTEMPTING TO REINSTALL THE PANEL COVER LID, HE TURNED WHILE LIFTING THE PANEL LID, EXPERIENCED PAIN TO HIS LOW BACK. CONTINUED TO WORK ALL SCHEDULED SHIFTS UNTIL 12/22/04. STARTED MISSING WORK ON THAT DATE, BECAME A REPORTABLE INJURY ON 12/22/04.