Abstract
To investigate the cause of spasticity, which is arisen with problems of the nervous system such as spinal cord injury (SCI) and to evaluate the level quantitatively, we aimed to construct neuro-musculo-skeletal model considering the mechanism of stretch reflex, the control of extrapyramidal system, and the recurrent inhibition by Renshaw cell and so on, and to simulate the pendulum movement of the knee joint with spasm. The influence of the neuronal parameters in the model to the movement was investigated and it was found that the movement became closer to that of a spasm patient if the time constant of brainstem increased. These results show that the transmission characteristic of extrapyramidal system may be related to the cause of spasticity.
