Approximately 70% of the upper extremity amputations refers to partial hand loss with the involvement of one or more fingers. Historically, this type of limb amputation has been addressed adopting simple opposition designs that use the movement of the residual digit for grasping against a fixed device. Nevertheless, in the last few years, technological advances, and the introduction of modern computer-aided tools for the synthesis and functional design of mechanisms have led to the development of smaller, more robust systems that are constantly improving body-powered and electrically-powered prototypes. This paper surveys cutting-edge solutions proposed in research or available on the market for single finger or partial hand prostheses. First, the main design requirements are outlined. Then, a wide number of prototypes are detailed underlying advantages and drawbacks. The overall goal is to create a solid starting point for the study and development of the next generation of prostheses that can be developed to advance the current state-of-the-art.

Background/Objectives: Upper limb amputation presents considerable physical and psychological challenges, especially in young, active individuals. This case study outlines the rehabilitation journey of a 33-year-old patient, an Italian national Paralympic snowboard cross athlete, who underwent elective transradial amputation followed by advanced surgical and prosthetic interventions. The objective was to assess the combined impact of upper limb Targeted Sensory Reinnervation (ulTSR) and the Adam’s Hand prosthetic system on functional recovery and user satisfaction. Methods: After a partial brachial plexus injury caused complete paralysis of his right hand, the patient opted for transradial amputation. He subsequently underwent ulTSR, performed by plastic surgeon, Alexander Gardetto, MD, which involved rerouting sensory nerves to defined regions of the residual limb in order to reestablish a phantom limb map. This reinnervation was designed to facilitate improved prosthetic integration. The Adam’s Hand, a myoelectric prosthesis with AI-based pattern recognition, was selected for its compatibility with TSR and intuitive control. Outcomes were evaluated using the OPUS questionnaire, the DASH, and patient feedback. Results: ulTSR successfully restored meaningful sensory input, allowing intuitive and precise control of the prosthesis, with minimal cognitive and muscular effort. The patient regained the ability to perform numerous activities of daily living such as dressing, eating, lifting, and fine motor tasks—which had been impossible for over 15 years. OPUS results demonstrated significant improvements in both function and satisfaction. Conclusions: This case highlights the synergistic benefits of combining ulTSR with user-centered prosthetic technology. Surgical neurorehabilitation, paired with advanced prosthetic design, led to marked improvements in autonomy, performance, and quality of life in a high-performance amputee athlete.

Introduction: Adaptive polyarticulated myoelectric hands aim to improve grasp versatility and intuitiveness of use; however, objective clinical and biomechanical evidence supporting their functional impact remains limited. Case presentation: A 75-year-old right-hand-dominant male with a long-standing transradial traumatic amputation and over 30 years of experience with a myoelectric tridigital prosthesis underwent experimental evaluation of an adaptive polyarticulated myoelectric hand (Adam’s Hand^®). Methods: Assessment included patient-reported outcome measures (Orthotics and Prosthetics User Survey—Upper Extremity Functional Status (OPUS-UEFS), Trinity Amputation and Prosthesis Experience Scales–Revised (TAPES-R), Disabilities of the Arm, Shoulder and Hand questionnaire (DASH), Short Form Health Survey 36 (SF-36)), standardized performance-based functional tests (Minnesota Manual Dexterity Test (MMDT), Box and Block Test (BBT), Southampton Hand Assessment Procedure (SHAP)), and laboratory-based biomechanical evaluation using optoelectronic motion capture and surface electromyography during Pointing, Hand-to-Mouth, and Grasping tasks. The adaptive prosthesis was tested after rapid artificial intelligence-based calibration, without structured training. Results: Patient-reported outcomes reflected high satisfaction and adaptation to the habitual prosthesis. Performance-based tests favored the habitual device in speed and dexterity, whereas the adaptive hand enabled additional grasp patterns. Biomechanically, the adaptive hand was smoother and faster during reaching, but less stable during grasping. Compensatory trunk and shoulder movements occurred with both devices, with a trend toward less compensation during reaching with the adaptive hand. Conclusions: This case highlights a task-dependent biomechanical profile of an adaptive polyarticulated myoelectric hand under first-use conditions. Rapid calibration may support immediate use for reaching, while optimal grasp control appears to require structured training.