Leg (anatomy)
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In zoological anatomy, a leg is any one of the parts of an animal's body that (in most legged species and at most times) support the rest of the body above the ground, and are used for locomotion.
Legs are most common in even-numbered quantities that are characteristic of some taxonomic groups:
- in vertebrates, 2 (the bipeds) or 4 (the quadrupeds);
- in many familiar arthropods, 6, 8, or 12;
- in some arthropods, more than a dozen and sometimes over 100 -- but despite what their names might suggest,
- centipedes seldom have exactly a hundred, and
- millipedes apparently never even approach a thousand.
The human leg of course shares all the properties that are common to all non-human animals, and in particular, shares the more extensive properties that are common to all other mammals.
Conversely, (nearly all) humans are legged animals and thus have several kinds of specialized resources available for studying and understanding non-human legs:
- an accumulation of experience with the functioning (and occasional malfunctioning) of one type of animal leg;
- the immediate opportunity to physically inspect a leg, and in fact to conduct experiments that have as results the collecting of some of the information transmitted in the leg's neurological system;
- information about the anatomy and dynamics of the human leg that is socially transmitted for purposes related to health or to practical exploitation of one's own legs.de:Bein