Kinematic and Kinetic Analysis of Human Motion as Design Input for an Upper Extremity Bracing System

Abstract

Upper extremity motion in humans is complex and irregular. An orthosis designer cannot count on cyclic procedures or repetitions. When designing a bracing system for the upper limb, this complexity is challenging and therefore it is essential to know about the necessary torques, angular velocities and joint ranges. In this study, we took a closer look at tasks associated with daily living and defined requirements for an upper limb orthotic device. The required working range of the assistive device in order to cover the required range of motion (ROM) was defined. Furthermore, external torques were assessed to facilitate the dimensioning of locking and weight compensation systems and to support strength calculation. The angular velocity at each joint of interest was calculated, as required e.g. for hydraulic component design. Prior to the development of a prototype, an evaluation of the defined joint ranges was envisioned. Additionally we investigated the effect of restricted joint angle ranges on movement performance.