Kinematic Model for Determination of Human Arm Reachable Workspace

In physiotherapy, a standard method to determine the movability and functionality of the human arm is to measure the ranges of motion in joints in sagittal, horizontal and frontal plane. It is clear, however, that these angles can hardly interpret the characteristics of the arm. The main idea in the article is to combine these angles with an adequate kinematic model in order to compute and graphically represent the reachable workspace of the arm, which then serves as an advanced criterion for a more objective evaluation. In this article, we report an improved kinematic model of the human arm which is appropriate for computing and visualizing the human arm reachable workspace. Optical measurements were performed to define the structure and parameters of the model and to develop the mathematical relations between the joint angles. The kinematic model was implemented in a computer programme which is now being introduced in practice and can be used in rehabilitation, ergonomics and sports.