Developing a finger joint biomechanics through dynamic hand model

Abstract

The human hand is one of the main limbs in maintaining daily life activities. It functions as an interface between the outside world and the brain, such as positioning, moving, touching, feeling, and grasping objects. It can perform fine motor skills precisely, thanks to its high degree of freedom of hand and its complex and flexible structure. This study proposes a dynamic human hand model with 15 degrees of freedom for rehabilitation purposes, reflecting the aforesaid abilities with significant accuracy. For the finger biomechanics design, finger joint lengths, angular workspace ranges, and joint torques were determined experimentally. Besides, joint torques during finger extension/flexion movements were calculated with the SolidWorks (SW) motion analysis and Ansys static structural analysis. To identify finger joint relationships, the workspaces for all fingers were computed and visualized during flexion/extension movements. Unlike the literature, the hand model includes a biomechanics computational analysis approach that makes it easy to adapt to hand models. The search demonstrates that using optimum comparative data for design parameters and fingers workspace ranges yields a cost-effective result for manufacturing a precision hand robot.