An employee was using a forklift to move a rolling cart with a spiral weldment. As he was pushing the spiral and cart, the forklift entered an inclined area. The front of the cart and the spiral started drifting/rolling down the incline. He put the forklift in reverse and backed up to get in front of the spiral and cart as it was rolling and then reached out with his right hand to deflect the cart's direction of travel. His right finger middle finger was then caught and crushed between the spiral and the roll cage of the forklift.