Modeling of neuromotor control mechanism for computer simulation of movements of human extremities

In order to investigate characteristics of the mechanism of neuromotor control for movements of upper and lower human extremities, by using a computer simulation method, the whole process comprising the generation of motor commands at the neural level, the contraction of muscles at the physiological level, and movements of the extremities at the dynamic level is modeled for computer-programming. At the neural level, the changes in the degree of contraction of muscles which are necessary for the movement of extremities are estimated from the target dynamic action, and the change in motor commands for the muscle contraction is derived. Then, through the changes in muscle contraction and corresponding muscle force at the physiological level, three-dimensional movement of the upper extremities and movement of the lower extremities in the sagittal plane are synthesized, and the force acting at the action point is derived, using anatomical structure models at the dynamic level. The model is designed with special regard to the analysis of the reflex action induced by prestretching of muscles, so that the result of simulation at each stage of the processes of the generation and modification of motor commands can be related to the observed electromyographic data