An employee was helping the driver of a winch truck back up and hook up to a tank. When the driver was close enough to the tank to hook up, the employee told him to stop and set the brakes. The driver did stop and set the brakes, but the truck was still in gear and jerked backwards when his foot came off of the clutch. The employee had moved between the truck and the tank to connect the winch line and was struck causing a fracture of the right femur.