The present invention is a mobility device, (also referred to as a “rollator”), which provides a weight bearing architecture and enables the user to maintain an erect body posture and body weight support through the upper arms while enabling the legs to freely move under the user's center of body weight. Upper arm support is enabled through padded forearm rests, or “arm saddles”, which provide an elevated cushion rearward to support and position the user's elbows and transfer the center of the body weight vertically downward and through the rollator frame and thereby falling within its base of support as defined by its four support wheels. The invention's base of support is smaller than conventional rollators, thereby enabling responsive rotational movement by transferring the user's spinal rotation through the aforementioned arm saddles to the rollator frame resulting in a low-radius turn.