Accurate geometrical constraints for the computer aided modelling of the human upper limb

For medical and surgical applications, human modelling and simulation have to be very accurate and realistic. This means that both geometries and movements have to be reproduced precisely, investigating both physiological properties and anatomical shapes. This paper deals with the description of geometrical constraints to mimic the movement of the upper limb segments subjected to physical joints. Anatomical studies show that relative motion cannot be approximated with basic constraints such as revolute or spherical joints, but requires the definition of specific geometrical and kinematic pairs. For this purpose, for each joint the authors deduce a set of equations which can be embedded into a virtual environment in order to simulate the relative motion among body segments in a detailed way.