An adaptable mobility aid device is disclosed that has length-adjustable front and rear legs, a handle, and a knee support platform coupled to the legs and the handle, the legs being adjustable within a range of lengths suitable to straddle steps for ascending and descending stairways, as well as to function on the level, or on a ramp. The lengths of the legs can be adjusted in tandem via single-hand operability of an adjustment mechanism. The knee support platform provides support for an impaired lower leg of a user, not requiring the leg to contact the stairs, and also not requiring the leg to be held mid-air in a hopping motion. The handle enables one-handed use of the adaptable mobility aid device. In some embodiments, spring loaded pins or a pull bar to activate the pins, enable the single-hand operability of the adjustment mechanism.
