Locomotion

locomotion

[‚lō·kə′mō·shən]

(science and technology)

Progressive movement, as of an animal or a vehicle.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Locomotion

 

in animals and man, a variety of movement, described by an active shift of the body in space, that includes swimming, flying, and various kinds of movement on the ground (including man’s walking and running).

Locomotion plays an enormously important role in the life of animals. For example, they move when seeking food and escaping enemies. There are many kinds of locomotion, from the very simplest amoeboid movements of some unicellular organisms to complex locomotor acts.

The kinds of locomotion have changed and become more complex during the course of animal evolution, and they have largely determined the structural characteristics of the animals. The appearance of new kinds of locomotion is associated with improvements of the locomotor apparatus, the sense organs, and, especially, the central nervous system. Locomotion is most complex and varied in vertebrates, a brilliant example of the relationship between form and function in evolution (see Figure 1); it includes swimming, flying, gliding, climbing, jumping, brachiation (swinging by the arms), and walking and running on four or on two legs.

The various gaits (walk, trot, amble, four-legged or two-legged ricochet, gallop), unlike the methods of locomotion, are determined not by the structure of the locomotor apparatus but by differences in the coordination of the extremities. The changes in locomotion during the course of the transformation of ape to man have played an exceptionally important role: climbing trees facilitated the formation of the grasping organs—the hands— and the transition to walking upright freed the hands for use as organs of work.

REFERENCES

Bernshtein, N. A. Ocherki po fiziologii dvizhenii i fiziologii aktivnosti. Moscow, 1966.
Sukhanov, V. B. Obshchaia sistema simmetrichnoi lokomotsii nazemnykh pozvonochnykh i osobennosti peredvizheniia nizshikh tetrapod. Moscow, 1966.
Gambarian, P. P. Beg mlekopitaiushchikh: Prisposobitel’nye osobennosti organov dvizheniia. Leningrad, 1972.
Granit, R. Osnovy reguliatsii dvizhenii. Moscow, 1973. (Translated from English.)
Howell, A. B. Speed in Animals. Chicago, 1944.
Gray, J. Animal Locomotion. London, 1968.

V. B. SUKHANOV

Figure 1. The original mode of locomotion was swimming by flexing the body in a horizontal plane. With the emergence of animals onto dry land, the extremities became the chief organs of locomotion. The basic form of locomotion of terrestrial vertebrates is walking and, for high speeds, running (on four or, less commonly, on two legs). There are two main types of terrestrial locomotion: symmetrical, in which the extremities operate alternately (the front paw always being followed by the hind paw diagonal to it, and rarely the reverse), and asymmetrical, in which the hind paws work alternately or synchronously with the front paws. The earliest terrestrial vertebrates traveled by symmetrical locomotion at a gait by which all paws worked by turn at equal intervals. The need for more rapid locomotion, combined with inadequacies of the locomoter apparatus itself, resulted in a change in rhythm. The interval in the operation of diagonal extremities diminished, while that of extremities on the same side increased: first, a trotlike walk developed; subsequently, a trot developed with diagonal extremities working in unison. Only when the locomotor apparatus improved radically (coinciding with the appearance of mammals) did the amble (whereby extremities on the same side worked in unison) and asymmetrical locomotion (more efficient and swifter than symmetrical) develop. This led to the appearance of the four-legged ricochet, from which evolved the gallop (the most progressive form of locomotion and characteristic only of mammals).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.