US Patent 9109396 Ladder having narrow base

A ladder includes a stair section having a plurality of steps, a vertical upright that connects to a top of the stair section, a base that connects a bottom of the stair section and a bottom of the vertical upright, and one or more wheels connected to the bottom of the vertical upright. The ladder may also include a front locking step and a rear wheel assembly. A narrow base extends between a step of the stair section above a bottom step or locking step and the vertical upright.