An employee was walking in a shipping area. On the floor was a 68-inch piston rod to be boxed and shipped out. One end of the rod was propped up on a 5-inch tall box with a protruding piston nut installed on this raised end. Adjacent to the raised piston end was another box containing a part ready to be shipped. The employee stepped around this boxed part with her right foot and then, while attempting to step over the raised end of the 68-inch piston with her left foot, caught her left boot toe on the protruding nut, causing her to trip and fall to the ground. The employee sustained a fractured left humerus.