An employee transported a sofa on a four-wheeled cart to a container truck and unloaded it at the rear of the container. He then positioned himself in front of the sofa to push it farther into the truck when the cart, which was set on a slight ramp, rolled into the back of his left leg. He lifted his leg rapidly and it hit the bottom of the cart. He suffered a laceration to the back of his lower left leg and tendon.