END OF SHIFT, EMPLOYEE PARKED THE 330-C EXCAVATOR, WAS DISMOUNTING FROM EQUIPMENT. FOOT CAUGHT ON DOOR FRAME & CAUSING HIM TO LOOSE BALANCE AND SLIP/FALL. LEFT HAND GRIPPING HAND RAIL - CAUGHT BODY WEIGHT AS HE FELL CAUSING PAIN IN LEFT SHOULDER. HE REPORTED INCIDENT ON 9/16/2011 @ 6:00 A.M. WENT TO HOSPITAL-GOT X-RAYS, SAID EVERYTHING OK. HE WENT BACK TO WORK.