Abstract: A walker having a readily adjustable and disassemblable frame is equipped with two wheels in the rear and a centered lead wheel. The lead wheel, which is castored for increased directional stability, is equipped with a brake operated by a foot pedal. When the pedal is depressed, an axle on which the lead wheel rotates is forced toward the front of a pair of elongated slots in a wheel bracket. The top of the wheel then contacts a friction pad to apply a braking force. The user can depress the brake pedal with the toe of one foot without lifting the heel.