Abstract: A longitudinal, substantially cylindrical shaped inflatable bladder for inserting within the palmar region of a constricted hand to extend the fingers outwardly and to promote exercise of the constricted hand. The bladder has a channel for receiving an end portion of a static hand orthosis permitting the inflatable bladder to be attached to a static hand orthosis. The bladder is further provided with a plurality of longitudinally extending partitions forming a network of connected fluid retaining pockets. The fluid retaining pockets permitting the bladder to inflate such that pressure is applied to the palmar region of the constricted hand between three natural arches of the hand promoting restoration of the concave depression of the palm and a functional position of the hand.