Forces, activation and displacement prediction during free movement in the hand and forearm

This paper deals with the development of a highly realistic human hand and forearm model. The model contains 38 muscles and 24 degrees of freedom representing the joints of the system. The adopted model has to be as close as possible to the reality of the human being hand, to address several features linked to manipulation tasks, grasping objects and daily routine movements like shaving, writing, etc. In addition, a better comprehension of the biomechanical and neuromuscular behavior of the system is aimed. This will allow having a tool for the simulation of repairing surgery, acts such as tendon transfer. In this paper, we focus on the muscle forces determination for a given task. An optimization technique is used to resolve the redundant problem over the 24 joints of the system. Also, a muscle model is used and is integrated in the optimization technique, in order to determine measurable values, like the activation and the displacement of each muscle in the system. The calculation is made during a real-time simulation. (C) 2005 Wiley Periodicals, Inc.