Kinematic analysis of the finger exoskeleton movement in distal and proximal interphalangeal joints

Abstract

Hand fingers have a high chance for injury during everyday life. Recovery of injured fingers is realized by physiotherapists, which manually conduct exercises. To help in therapy researchers are constantly inventing new methods of applying mechanical devices in the rehabilitation process. Actually there are conducted many studies of passive and active exoskeletons. Properly designed exoskeleton can help in movement and rehabilitation of paralyzed or not fully functional part of human body. It can be used also to increase human movement capabilities. This paper is a continuation of previously presented kinematic analysis of finger exoskeleton design which is based on three-link subsystem and one finger-leading link. In actual system the finger leading link is replaced by an exoskeleton that allows movement in distal and proximal interphalangeal finger joints. The main advantage of proposed design is that during operation finger is fully supported by the exoskeleton and there are no additional loads applied on its joints. The actually presented part of the full finger exoskeleton can be analyzed as an individual mechanism because in natural system the finger movement in metacarpophalangeal joint is realized separately in comparison to the movement in distal and proximal interphalangeal joints. The kinematic data are needed for the next step of design process, which define the dynamic forces acting in the system. This will allow the selection of actuators and proper design of all exoskeleton mechanical parts that will be used in a real life model.