Abstract: An inflatable hand orthosis promotes a functional positioning of the fingers and thumb. An inflatable air bladder is formed by two vinyl sheets bonded together and inflated and deflated by a pump bulb and-deflation valve, respectively, which are fixed to the vinyl sheets and communicatingly interconnected with the air bladder. The bladder is sewn into a soft cloth covering in order to form a wearable device which may be used either alone or in conjunction with hand, wrist, and finger orthosis. The hand device is placed on the palm and under the patient's fingers while deflated. Then the bladder is inflated to align and extend the fingers and to abduct the thumb.