EE STEPPED OUT OF CAB OF VEHICLE AND HIS FOOT SLIPPED OUT FROM UNDER HIM CAUSING EE TO FALL BACKWARDS ONTO THE FLATBED OF THE TRUCK JAMMING HIS LEFT SHOULDER. THE EE DID NOT REPORT THIS INCIDE NT TO EMPLOYER UNTIL 1/5/04 & HAS NOT MISSED ANYDAYS FROM WORK OR HAD RESTRICTED DUTY. EMPLOYER MADE AWARE ON 2/3/04 THAT EE IS SEEING A CHIROPRACTOR, MAKING THIS REPORTABLE. CHIRO IS 1ST MED