EMPLOYEE WAS MAKING A LIFT WITH THE BOOM TRUCK. LIFTING A PIECE OF PIPE 40 ' LONG 6"" DIAMETER, WHILE ROTATING THE PIPE THE LOAD SWUNG IN THE DIRECTION OF THE BOOM TRUCK OPERATOR. HE PUT HIS H AND OUT TO STOP THE SWING OF THE PIPE. THE OPERATOR HAD HIS THUMB ON HIS RIGHTHAND JAMMED BETWEEN PIPE AND HANDRAIL OF TRUCK.