Neuro-Aligned Tactile Feedback for Upper Limb Prostheses: A Neuroanatomical Review and Evaluation Framework

Abstract

Upper limb prostheses fail to deliver complete tactile sensation, so most users depend on visual guidance and excessively adjust their grasping movements. The core research focus has shifted from integrating sensory feedback to selecting optimal stimulation strategies for generating tactile perception that is functional, anatomically consistent and neurophysiologically natural. This paper presents a PRISMA-informed scoping review of recent tactile feedback published from January 1, 2020, to May 31, 2026, then integrates classic anatomy and neuroprosthetic papers to build a compact evaluation framework. The initial search retrieved 136 records from PubMed. After removing 4 duplicate entries, 132 unique articles were screened by title and abstract. A total of 20 full-text articles were evaluated, among which 16 studies were finally included. Another eight landmark studies were manually retrieved from Google Scholar, Web of Science and IEEE Xplore to supplement the analysis of cortical mapping, mechanoreceptors, proprioception, motor unit recruitment and interface evolution. The synthesis shows that the strongest studies do not optimize stimulus intensity alone. They align stimulation site, encoding rule, and evaluation metrics with the upper limb afferent route from cutaneous receptors to somatotopic hand area (S1) and with the motor route that stabilizes grasp through corticospinal drive and residual muscle recruitment. On the basis of the synthesis, this work proposes a neuroanatomical mechanism diagram and a three-part evaluation criterion covering perceptual realism, functional utility, and neural congruence. The proposed framework provides a practical evaluation scaffold for selecting tactile feedback strategies in future bionic limb studies.