I T has long been apparent that a definite need existed for upper extremity prostheses which are lighter, more comfortable and possess greater versatility. However, no singIe cIinic or manufacturer has had the material, time or funds to embark upon an investigative program of the magnitude required. It was clear that strong support and a broad program involving not onIy technical developments but also eIements of prosthetics practice were necessary to bring the heId of prosthetics to a position abreast of modern science and technoIogy. In 1945 the Advisory Committee on Artificial Limbs of the National Research Council and the Prosthetic and Sensory Aids Service of the Veterans Administration undertook the direction and financing of a research program dedicated to the deveIopment of improved artificial arms. Portions of this work were assigned to a number of engineering firms, limb manufacturers and research organizations. Correlation of the resuIts and the most significant contributions to the program of research and development has been the work of the Northrop Aircraft Co., The Army Prosthetic Research Laboratory and the Department of Engineering at the University of California, Los Angeles. Concomitantly, the limb industry through the Orthopedic AppIiante and Limb Manufacturers Association has acted to upgrade its standards by instituting a training and certification program for limb makers and by offering practica1 heIp and advice to the research and deveIopment program. The resuIts of these investigations can best be stated in terms of the prosthetic replacement that is now possible with improved devices. This is shown in Figure I in which the natural functions Iost at each amputation site are indicated together with the avaiIabIe prosthetic replacement. The chart shows that it is now possibte to regain a11 of the major motions of the arm. Although it cannot be said that these amputee motions can be accomplished with a11 the grace of the natural mechanism, no major action is tacking and the range of motions possible includes a11 that are essential to activities of everyday living. Detailed discussion of the newer prosthetic devices can best be carried out under the general headings of (I) devices which are generaIIy appIicabIe, (2) the below-elbow prosthesis, (3) the above-elbow prosthesis, (4) shouIder disarticuIation, (5) cineplastic appIications and (6) the prosthetics team necessary to conduct the quaIity of amputee service consistant with the new technoIogy.