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A leg is a weight bearing and locomotive structure, usually having a columnar shape. During locomotion, legs function as "extensible struts".〔(【引用サイトリンク】publisher=Biologists.org )〕 The combination of movements at all joints can be modeled as a single, linear element capable of changing length and rotating about an omnidirectional "hip" joint. As an anatomical animal structure it is used for locomotion. The distal end is often modified to distribute force (such as a foot). Most animals have an even number of legs. As a component of furniture it is used for the economy of materials needed to provide the support for the useful surface, the table top or chair seat. ==Terminology== *Uniped: 1 leg, such as clams *Biped: 2 legs, such as humans and birds *Triped: 3 legs, which does not occur naturally in healthy animals *Quadruped: 4 legs, such as dogs and horses. Many taxa are characterized by the number of legs: *Tetrapods have four legs. *Arthropoda: 4, 6 (Insecta), 8, 12, or 14 legs. Some arthropods have more than a dozen legs; a few species possess over 100. Despite what their names might suggest, centipedes ("hundred feet") may have fewer than 20 or more than 300 legs, and millipedes ("thousand feet") have fewer than 1,000 legs, but up to 750. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「leg」の詳細全文を読む スポンサード リンク
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