An employee was standing on the passenger-side rear step of a recycling truck, moving house to house to pick up recycling material. The sweep blade in the truck's hopper activated and began to push a cardboard box out of the hopper. As the employee tried to keep the box from falling out of the back of the truck, his foot became lodged in the box; the sweep blade came down on the box and his left foot, causing a compound fracture of his ankle as well as a muscle injury.