A personal mobility device comprising an open frame having a front structure, a rear structure, and a side structure. The side structure has an upper rail and a lower rail coupleable to the front structure and the rear structure. In one embodiment, a main mobility wheel is coupled to the side structure, and a knee rest is rotatably coupled to the front structure. The knee rest is adjustable from a first substantially-vertical position coupled to the front structure to a second rearwardly and downwardly-angled position from the front structure.