THE EE WAS EXITING THE CAB OF THE LOADER, THE EE STUBBED HIS FOOT ON ONE OF THE HINGES CAUSING HIM TO LOSE HIS BALANCE. EE CAUGHT HIMSELF ON THE HANDRAIL AND JAMMED HIS LEFT SHOULDER AGAINST T HE HANDRAIL OR THE CONTROL SWITCH OF THE BOARDING LADDER MOUNTED ON THE HANDRAIL. EE COMPLETED HIS WORK SHIFT COMPLAINING ABOUT SORENESS AND NUMBNESS IN HIS LEFT SHOULDER.