The method of determining the forces in the tendon apparatus of human fingers

Abstract

Being one of the most functionally loaded systems, the human hand and its anatomical structures are damaged quite often. Thus, injuries to the interphalangeal joints account for up to 60 % of all hand injuries. Post-traumatic arthrosis, contractures with persistent pain syndrome, stiffness and ankylosis of the joints are distinguished among the consequences of hand joint injuries. With the development of the endoprosthesis method, the use of which allows to restore the lost function of the organs of the musculoskeletal system, new opportunities are opening up in the rehabilitation of patients with various injuries of the joints of the hand. However, when using this method, there are certain complications associated with the wear of the implant, the reaction of the surrounding tissues to the material from which the prosthesis is made, and the design features of endoprostheses. That is, the success of treatment when using endoprostheses depends to some extent on the design of the implant. It is possible to carry out a primary analysis of the effectiveness of the proposed design of the endoprosthesis with the help of specialized software complexes. Despite the power of specialized software, building digital models of biological objects and performing calculations is quite a difficult task. In order to carry out a numerical study, in addition to knowing of the geometry of objects and their mechanical properties, it is also necessary to understand the conditions of interaction between the model fragments and the loading scheme. Aim. Develop a technique for analytical determination of forces in the tendons of the fingers. Materials and methods. The research was carried out using the provisions and methods of theoretical mechanics and resistance of materials. As a calculation case, this paper proposes to consider the determination of forces in the tendons of the index finger of the right upper limb. Results. As a result of the performed calculations, analytical expressions were obtained to determine the forces that occur in the flexor tendons of the index finger. Conclusions. The obtained analytical expressions allow us to estimate the magnitude of forces that occur in the tendons of the fingers. The results of the calculations can be used in the construction of digital models of the fingers and perform numerical studies.