The use of control theory to provide insight into neurophysiology has a long history. As

Chapter 0, Problem DP12.6

(choose chapter or problem)

The use of control theory to provide insight into neurophysiology has a long history. As early as the beginning of the last century, many investigators described a muscle control phenomenon caused by the feedback action of muscle spindles and by sensors based on a combination of muscle length and rate of change of muscle length. This analysis of muscle regulation has been based on the theory of single-input, single-output control systems. An example is a proposal that the stretch reflex is an experimental observation of a motor control strategy, namely, control of individual muscle length by the spindles. Others later proposed the regulation of individual muscle stiffness (by sensors of both length and force) as the motor control strategy [30]. One model of the human standing-balance mechanism is shown in Figure DPI2.6. Consider the case of a paraplegic who has lost control of his standing mechanism. We propose to add an artificial