Existing prosthetic shoulder modules control humeral flexion either by applying light frictional drag or by operating in one of two discrete user-selectable modes: free-swing or fully locked. In many cases, limited functionality forces users to move in peculiar and potentially embarrassing ways to operate their shoulders, while others cannot operate existing devices at all. Although there is clearly substantial room for improvement in the design of upper-limb prosthetics, it is a niche market that fails to attract the R&D funding needed for significant technical advances. ADA proposes to apply funding to create the affordable, full-function prosthetic shoulder that is needed. [unreadable] Under an earlier NIH-funded SBIR project, ADA developed an innovative gripper drive mechanism that, when scaled properly, will offer precisely those qualities needed for a new benchmark shoulder module, including: 1) smooth and intuitive operation over a natural spectrum of function [i.e., user-controlled frictional drag from free-swing up to fully locked]; 2) automatic, self-resetting overload protection for users' safety; and 3) proprioceptive cable actuation and proportional electronic control options. [unreadable] This multi-phase SBIR project ideally matches the intent of NIH's special solicitation - the commercialization of new assistive technologies for the disabled. ADA's specific Phase I goal is to show that a robust, full-function shoulder module is technically feasible. In Phase II, a marketable device will be developed and validated through extensive human subject field trials; commercialization will follow in Phase III with the launch of a "building block" product under PhysioNetics(r), a new spin-off company being formed under ADA. This new company aims to bring the best-possible new assistive technologies to market for the benefit of those men and women who need them to achieve and preserve their quality of life. [unreadable] [unreadable]