A simulation study of agonist-antagonist muscle action in the human arm during constrained movements

We simulate the dynamic interaction between the human arm and a machine that imposes a continuous constraint on the arm. Results indicate oscillatory behavior of the system when disturbances are applied to the arm at high co-contraction levels. The modeling presented here is useful in the areas of design and control of exercise and rehabilitation machines that are to interact with the human via control signals as well as power.