PULLING #144 SHIELD OFF LINE. AFTER SHIELD WAS REMOVED, MEMBER STARTED SETTING 10"" PROPSETTER WHERE THE SHIELD WAS LOCATED. CO-WORKER HAD PROP STOOD UP AND READY TO BE WEDGED. AS EE STARTED TO WEDGE THE PROP A ROCK 4' X 4' X 8"" STRUCK HIM ON THE LEFT HAND CAUSING A HAIRLINE FRACTURE.