The invention relates to an aerial work platform including: a frame (1) mounted on wheels (4, 5); a work platform (3) mounted on a lifting mechanism (2); two side bars (10) arranged under the frame and movable relative to said frame between: either a raised position, and/or a lowered position in which said bars extend past the frame toward the ground; and an actuator (30) assigned solely to actuating the two bars to move said bars between these two positions, the actuator having two opposite ends by means of which said actuator moves the two bars by varying the distance between the two ends. The actuator moves each of the two bars by means of another of the two ends and is maintained only by the two ends. This actuation device is particularly simple, compact, and cost effective.