Biomechanics and Ergonomics

The human hand is a highly complex system with 25 main degrees of freedom. This kinematic complexity grants the hand its crucial abilities for gripping and manipulation, essential for carrying out the daily activities of human life. Therefore, biomechanical models of the human hand have been developed in the literature to simulate various aspects related to gripping and manipulation. These biomechanical models provide the capability to analyze problems that would otherwise be difficult to address directly in individuals or would involve significant experimental costs. In recent years, parametric models have been developed that allow the customization of the model's geometry according to anthropometric data obtained through 3D scanning techniques. However, it is important to highlight that most of these studies have focused on the investigation of healthy hands with normative behavior. Therefore, it would be interesting to study the morphology of non-normative hands (e.g., patients with osteoarthritis or rheumatoid arthritis) to apply this to parametric kinematic hand models. Some works in the literature have already been studying the automated extraction of anthropometric measurements from 3D models, obtaining good results. However, there is a lack of specific protocols to ensure the success and reproducibility of hand scanning techniques. Therefore, the first objective of this project is to develop a 3D hand scanning protocol (Objective 1) and to create a database of scanned hands (Objective 2) that includes both healthy hands and those with deformities (e.g., osteoarthritis patients). The creation of a 3D hand scan database encompassing a wide range of functional postures, such as different types of grips, would provide extremely valuable anthropometric data. This would allow the study of variations in hand morphology in both healthy individuals and those with pathological conditions, and would open doors to proposing indices to quantify joint deviations or changes in the morphology of pathological hands. Therefore, another objective of the project is to search for parameters and indicators of pathologies (Objective 3), such as hand osteoarthritis, which causes joint deformity and inflammation. Finally, the project aims to apply the obtained data to parametric kinematic hand models (Objective 4), which is another proposed objective of the project. All this would allow simulating the kinematic behavior of hands with certain pathologies, contributing to the knowledge and study of this segment of the population. The benefits of developing this project encompass scientific-technical, economic, and social aspects, as the proposed research is transversal, applicable to both the theoretical field of kinematic hand study, clinical diagnosis, or ergonomics.