EE WAS STANDING ON GROUND AND REACHED UP TO SET THE BRAKE ON A RAIL CAR. THE REACHEING ACTION CAUSED HIS LEFT SHOULDER TO DISLOCATE. NOTE EE REPORTS THAT HE HAS HAD SHOULDER DISLOCATE 2 YEARS AGO DUE TO A FIGHT AND AGAIN LAST YEAR IN ANOTHER NON-WORK RELATED EVENT. HE WAS TREATED AT THE HOSPITAL AND RELEASED TO LIGHT DUTY.