INJURED WAS PICKING UP PAPERS FROM A LOADER OPERATOR. EE STOPPED PICKUP PARALLEL TO LOADER & SLIGHLTY BEHIND LOADER. AFTER EE CLIMBED ONTO LOADER THE OPERATOR SAID THE PICKUP WAS ROLLING. PICK UP WAS TOO CLOSE TO LADDER, SO WHEN THE TRUCK CLEARED THE LADDER EE JUMPED FOR THE BUMPER, SLIPPED OFF AND STRUCK THE GROUND. HE GOT UP AND THEN STOPPED THE SLOW MOVING PICKUP TRUCK.