Employee raised bed of CAT 777 to allow access to fender. Raising the bed causes the front of truck to sit 4-6"" higher. When employee stepped down he felt twinge in his right knee. *THIS INCIDENT WAS NOT REPORTABLE UNTIL 11/19/2008 WHEN EMPLOYEE ASKED TO SEE DOCTOR FOR PAIN IN RIGHT KNEE. HE WAS PLACED ON RESTRICTED DUTY AS OF 11/19/2008 WITH RIGHT KNEE STRAIN.*