Motor control

Motor control is the process by which humans and animals use their brain/cognition to activate and coordinate the muscles and limbs involved in the performance of a motor skill. Fundamentally, it is the integration of sensory information, both about the world and the current state of the body, to determine the appropriate set of muscle forces and joint activations to generate some desired movement or action.

Overview

Motor control includes reflexes as well as directed movement. To control movement, the nervous system must integrate multimodal sensory information (both from the external world as well as proprioception) and elicit the necessary signals to recruit muscles to carry out a goal. Not only does the nervous system control the millions of muscle fibers to achieve a goal, it must also ensure the maintenance of posture during the goal-directed movement. These issues are the subject of ongoing debate within the field of motor control, and widely accepted theories of motor control currently do not exist.

Theories of Motor Control

There are several theories of motor control that attempt to explain how we control movement, although none is universally accepted. These include the Hierarchical theory, Systems theory, Dynamic action theory, Optimal control theory, and Internal model theory.

Hierarchical Theory

The Hierarchical theory is based on the idea that control of movement is organized in a top-down structure. Higher levels of the nervous system (such as the cortex) control lower levels (such as the spinal cord).

Systems Theory

The Systems theory of motor control views the nervous system as a part of a larger system that includes the mechanical properties of the body. This theory suggests that movement emerges from the interaction of the nervous system, the body, and the environment.

Dynamic Action Theory

The Dynamic action theory suggests that the control of movement is not entirely under the control of the nervous system, but also depends on the physical and mechanical properties of the body and the environment.

Optimal Control Theory

The Optimal control theory suggests that the nervous system controls movement in a way that minimizes some cost function. This could be energy expenditure, error, or some other measure of performance.

Internal Model Theory

The Internal model theory suggests that the nervous system maintains internal models of the body and the world that are used to control movement.

See also

• Motor coordination
• Motor learning
• Motor skill
• Motor cortex
• Motor system