Twenty five joints of 5” drill pipe were being picked up from the pipe rack in the yard and being sent to a rig. The drill pipe along with HW pipe were stored on the pipe racks in a heap. Eight joints of pipe were removed and the second set was in the process of being picked up from the rack. The forklift being used had 4 joints of pipe lying on the forks with a fifth joint that was only on one fork. The roustabout assisting in the task pushed the fifth joint toward the pipe rack to get it off the fork. After accomplishing this he positioned himself on top of the pipe on the rack, causing the pipe to roll forward and trap his foot between two joints. He suffered a fracture to his leg.