According to the DoD/VA Extremity Amputation Center of Excellence there were about 3,000 Veterans with transradial amputations enrolled for VA Healthcare in FY21. Veterans with arm amputations from Post-911 conflicts number just over 200, and because the total number of Veterans missing arms is demographically small, this very fact has limited innovation. Prosthetic arms are often uncomfortable which is generally attributable to the fit and comfort of sockets and harnesses and are not worn primarily for this reason. This research seeks to validate and improve upon preliminary results from an innovative new transradial socket and harness textile-based design inspired by advanced athletic shoe technology. We propose to employ a participatory action design and engineering (PADE) process for the proposed K-Socket-Harness (KSH) to include three basic phases: (1) Advance the current KSH design for manufacture and to be suitable for a broader population of Veterans with transradial amputations; (2) Evaluate the improved KSH design(s) with a selection of experienced Veterans with a range of different lengths and anatomies of transradial amputations and revise design based on their guidance; (3) Enroll a larger cohort to compare the improved KSH design to Veteran’s current prosthetic device through a series of activities designed to illicit differences if they exist. In Phases 1-3, we will recruit 5 experienced Veterans with transradial arm amputations to provide guidance and to assist with the design and development. In Phase - 3, We will recruit an additional 20 Veterans with transradial arm amputations to undergo a series of evaluative tests. We will recruit 5 Certified Prosthetists with at least 5-years of experience working with Veterans with transradial arm amputations to provide guidance and to assist with the design and development. If successful, the resulting KSH will provide an alternative for Veterans or augment current devices provided to improve function and reduce risk of injury. This study will employ an iterative PADE process involving input from Veterans with disabilities at various stages to inform the development and acceptance of KSH. KSH will be tested for usability and feasibility for improving comfort, function, acceptance, and range of motion. Experienced end-user Veterans and Clinical staff will be engaged to assist with design, develop the fitting process. Acceptance of prosthetic arms has long been a problem for clinical prosthetics, and recent studies indicate that recent advancements have done little to improve usage. Athletic footwear has evolved to accomplish many of the same difficult, diverse, and even contradictory tasks that face prosthetic upper limb socket design, and footwear design and production has evolved remarkably. With sufficient understanding of both shoe technology and prosthetic requirements, we can accrue to upper-limb prosthetics all the benefits of the modern materials and design/manufacturing techniques...