A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts".[1] 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, such as the table top or chair seat.
Many taxa are characterized by the number of legs:
Tetrapods have four legs. Squamates of genus Bipes have only two. Caecilians and many squamate lineages convergently lost their legs.
Panarthropoda: no less than 4 legs. Velvet worms and 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.
Components
A leg is a structure of gross anatomy, meaning that it is large enough to be seen unaided. The components depend on the animal. In humans and other mammals, a leg includes the bones, muscles, tendons, ligaments, blood vessels, nerves, and skin. In insects, the leg includes most of these things, except that insects have an exoskeleton that replaces the function of both the bones and the skin.
Sometimes the end of the leg, or foot, is considered part of the leg; other times it is considered separate. Similarly, the hip joint or other place where the leg attaches to the main body may be considered separate or part of the leg.
In tetrapodanatomy, leg is used to refer to the entire limb. In human medicine the precise definition refers[2][3][4] only to the segment between the knee and the ankle. This lower segment is also called the shank,[5][6] and the front (anterior) of the segment is called the shin or pretibia.
In bipedaltetrapods, the two lower limbs are referred to as the "legs" and the two upper limbs as "arms" or "wings" as the case may be.
A robotic leg is moved by an actuator, which is a type of motor for moving or controlling a mechanism or system. It is operated by a source of energy, usually in the form of an electric current, hydraulic fluid pressure or pneumatic pressure, and converts that energy into some kind of motion.
Prosthetic leg
Cameron de Burgh, an Australian Paralympic swimmer, who has a prosthetic leg
A prosthetic leg is an artificial leg that is used to replace one that has been lost.
References
^"Studies in the Mechanics of the Tetrapod Skeleton". Biologists.org. from the original on 9 July 2008. Retrieved 21 September 2010.
^"Leg". Medical Subject Headings (MeSH). National Library of Medicine. from the original on 2015-12-22. Retrieved 2009-04-18.
^"Leg". Dorland's Medical Dictionary for Healthcare Consumers. Mercksource. Archived from the original on 2011-10-14. Retrieved 2009-04-18.
this, article, about, legs, animals, general, legs, humans, human, other, uses, disambiguation, redirects, here, other, uses, disambiguation, weight, bearing, locomotive, anatomical, structure, usually, having, columnar, shape, during, locomotion, legs, functi. This article is about legs of animals in general For legs in humans see Human leg For other uses see Leg disambiguation Legs redirects here For other uses see Legs disambiguation A leg is a weight bearing and locomotive anatomical structure usually having a columnar shape During locomotion legs function as extensible struts 1 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 LegDiagram of an insect legDetailsIdentifiersLatinmembrum inferiusTA98A01 1 00 031TA2156FMA24879Anatomical terminology edit on Wikidata 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 such as the table top or chair seat Contents 1 Terminology 2 Components 3 Tetrapod legs 4 Arthropod leg 5 Robotic leg 6 Prosthetic leg 7 References 8 External linksTerminologyUniped 1 leg such as clams Biped 2 legs such as humans and birds Triped 3 legs which typically does not occur naturally in healthy animals Quadruped 4 legs such as dogs and horsesMany taxa are characterized by the number of legs Tetrapods have four legs Squamates of genus Bipes have only two Caecilians and many squamate lineages convergently lost their legs Panarthropoda no less than 4 legs Velvet worms and 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 ComponentsA leg is a structure of gross anatomy meaning that it is large enough to be seen unaided The components depend on the animal In humans and other mammals a leg includes the bones muscles tendons ligaments blood vessels nerves and skin In insects the leg includes most of these things except that insects have an exoskeleton that replaces the function of both the bones and the skin Sometimes the end of the leg or foot is considered part of the leg other times it is considered separate Similarly the hip joint or other place where the leg attaches to the main body may be considered separate or part of the leg Tetrapod legs nbsp The leg of a woolly mammoth reconstruction In tetrapod anatomy leg is used to refer to the entire limb In human medicine the precise definition refers 2 3 4 only to the segment between the knee and the ankle This lower segment is also called the shank 5 6 and the front anterior of the segment is called the shin or pretibia In bipedal tetrapods the two lower limbs are referred to as the legs and the two upper limbs as arms or wings as the case may be Human legArthropod legArthropod legRobotic legA robotic leg is moved by an actuator which is a type of motor for moving or controlling a mechanism or system It is operated by a source of energy usually in the form of an electric current hydraulic fluid pressure or pneumatic pressure and converts that energy into some kind of motion Prosthetic leg nbsp Cameron de Burgh an Australian Paralympic swimmer who has a prosthetic legA prosthetic leg is an artificial leg that is used to replace one that has been lost References Studies in the Mechanics of the Tetrapod Skeleton Biologists org Archived from the original on 9 July 2008 Retrieved 21 September 2010 Leg Medical Subject Headings MeSH National Library of Medicine Archived from the original on 2015 12 22 Retrieved 2009 04 18 Leg Dorland s Medical Dictionary for Healthcare Consumers Mercksource Archived from the original on 2011 10 14 Retrieved 2009 04 18 leg Merriam Webster com Dictionary Kardong Kenneth V 2009 Vertebrates Comparative anatomy function evolution 5th ed McGraw Hill p 340 ISBN 978 0 07 304058 5 shank Merriam Webster com Dictionary External links nbsp Media related to Leg at Wikimedia Commons Retrieved from https en wikipedia org w index php title Leg amp oldid 1196527152, wikipedia, wiki, book, books, library,
