Nervous Control of Movement

Abstract

The nervous control of movement involves the neuronal planning of movement trajectories and the maintenance of dynamic stability. It involves various sensory systems (such as muscle spindles) and effectors (such as muscles).

Keywords: control theory; proprioception; pattern generator; reflexes

Figure 1.

Block diagrams showing two main classes of control. (a) In open‐loop control, the system accepts input and produces output. The output is not fed back to the input. (b) In closed‐loop control, certain aspects of the output are measured and compared with a desired value. This ability requires a reference copy of the ideal performance within the nervous system.

Figure 2.

The knee‐jerk reflex. When the skin overlying the patellar tendon is ‘hit’ with a hammer the extensor muscles, including their muscle spindles, stretch. The stretched muscle spindles, which sense muscle strain and strain rate, activate afferent sensory neurons which in turn stimulate α motor neurons (and interneurons) in the grey matter of the spinal cord. The fast axons of these neurons subsequently stimulate the extensor muscle fibres, resulting in the knee‐jerk.

Figure 3.

Diagram of the main types of neurons in a segment of the spinal cord of the lamprey. C, E, L, interneurons; SR, stretch receptor; M, motor neurons. Redrawn after Ekeberg and Grillner (1999).

close

Further Reading

Dietz V (1992) Human neuronal control of automatic functional movements: interaction between central programs and afferent input. Physiological Reviews 72: 33–69.

Ekeberg Ö and Grillner S (1999) Simulations of neuromuscular control in lamprey swimming. Philosophical Transactions of the Royal Society. Series B: Biological Sciences 354: 895–902.

Harris CM and Wolpert DM (1998) Signal‐dependent noise determines motor planning. Nature 394: 780–784.

Hogan NJ (1984) An organizing principle for a class of voluntary movements. Journal of Neuroscience 4: 2745–2754.

Nelson WL (1983) Physical principles for economies of skilled movements. Biological Cybernetics 46: 135–147.

Schwarzenbach J and Gill KF (eds) (1992) System Modelling and Control, 3rd edn. London: Edward Arnold.

Van Leeuwen JL (ed.) (1999) Mechanisms of neuromuscular control. Philosophical Transactions of the Royal Society. Series B: Biological Sciences 354: 837–954.

Wagner H and Blickhan R (1999) Stabilizing function of skeletal muscles: an analytical investigation. Journal of Theoretical Biology 199: 163–179.

Wallén P, Ekeberg Ö, Lansner A, Brodin L, Tråvén H and Grillner S (1992) A computer based model for realistic simulations of neural networks. II The segmental network generating locomotor rhythmicity in the lamprey. Journal of Neurophysiology 68: 1939–1950.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
van Leeuwen, Johan L, and Spierts, Igor LY(May 2001) Nervous Control of Movement. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0001863]