The general problem of" control" may be divided into two main categories, often designated
open-loop and closed-loop (see Fig. 1). We adopt here the convention of using" controller" …

Traditionally, spinal control of motor output has been viewed as an attractive testing ground
for theories of neuronal computation both because of the opportunities to manipulate …

Four perspectives on motor control provide the framework for developing a comprehensive
theory of motor control in biological systems. The four perspectives, of decreasing orthodoxy …

6 Biological motor control can be characterized as a problem of con-7 trolling nonlinear,
unreliable systems whose states are monitored 8 with slow and sometimes low-quality …

Physiological principles of motor control have generally been based on linear servocontrol
theories in which transducers of force, length and velocity are used to provide feedback to …

Animals can produce a wide range of highly coordinated movements under a variety of
conditions. This ability requires the interaction of central commands with sensory feedback …

The sections in this article are:

One of the basic difficulties handicapping all research on the motor systems is the lack of a
unifying theory of motor function. With good reason it has been felt that the available …

Over the past decade, research at three different levels of sensorimotor control has revealed
a degree of complexity that challenges traditional hypotheses regarding servocontrol of …

The general topic of motor systems and their control can be considered at three hierarchical
levels: i) mechanical components and their properties; ii) control algorithms and their …