Virtual muscle: a computational approach to understanding the effects of muscle properties on motor control

This paper describes a computational approach to modeling the complex mecha nical properties of muscles and tendons under physiological conditions of r ecruitment and kinematics. It is embodied as a software package for use wit h Matlab(TM) and Simulink that allows the creation of realistic musculotend on elements for use in motor control simulations. The software employs grap hic user interfaces (GUI) and dynamic data exchange (DDE) to facilitate bui lding custom muscle model blocks and linking them to kinetic analyses of co mplete musculoskeletal systems. It is scalable in complexity and accuracy. The model is based on recently published data on muscle and tendon properti es measured in feline slow- and fast-twitch muscle, and incorporates a nove l approach to simulating recruitment and frequency modulation of different fiber-types in mixed muscles. This software is distributed freely over the Internet at http://ami.usc.edu/mddf/virtualmuscle. (C) 2000 Elsevier Scienc e B.V. All rights reserved.