An employee had finished working on a truck and went to let the jack down. The jack was all the way down but the tires were still off the ground. He jacked the truck back up and put a wood block under one side's tires and the old axle seats under the other side's tire. He then let the jack down again, but the truck still was not all the way down. He jacked the truck back up and slid one of the frame stands back under the rear frame section. He then put his left hand under the stand to push the tube up to the frame to pin the tube with his right hand. Before he got the pin in the tube, the truck came off the jack and fell onto the stand tube, catching and crushing his hand between the truck frame and the jack stand. He was hospitalized.