EE PULLED A JACK HAMMER OFF TAIL GATE OF PU TRK THE WEIGHT OF THE HAMMER PULLED & JERKED HIS LEFT SHOULDER. HE DID NOT REPORT INJURY AT FIRST BUT CONT'D TO WORK FOR SEVERAL DA;Y. THE PAIN CO NTD TO WORSEN UNTIL IT GOT TO A POINT HE HAD TO SEE A DR. BECAME A RESTRICTED WORK ON 1/30/01