EMPLOYEE HAD PLACED A DEAD MAN BLOCK IN FRONT OF THE CAR THEY WERE PREPARING TO COUPLE AND STABILIZE. AS HE TURNED HIS BACK TO THE CAR FACING THE MOTOR HE TOLD THE OPERTOR TO PULL OFF AND WH EN HE DID, THE DEAD MAN BLOCK SLID AND THE DRAWHEADS PINCHED HIM IN THE RIGHT CALF AREA.