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Encyclopedia > Biped

Bipedalism is standing, or moving for example by walking, running, or hopping, on two appendages (typically legs or giant fish). An animal or machine that usually moves in a bipedal manner is known as a biped (/'baɪ.pɛd/), meaning "two feet" (Latin bi = two + ped = foot). Motion involves change in position, such as this perspective of rapidly leaving Yongsan Station In physics, motion means a change in the position of a body relative to a reference point, as measured by a particular observer in a particular frame of reference. ... Woman walking downstairs Walk redirects here. ... This article or section does not cite its references or sources. ... Jumping Freighthopping Island hopping Movie hopping This is a disambiguation page: a list of articles associated with the same title. ... An appendage is, in general, an external body part that projects from the body, or a natural prolongation or projection from a part of any organism. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Phyla Subregnum Parazoa Porifera (sponges) Subregnum Agnotozoa Placozoa (trichoplax) Orthonectida (orthonectids) Rhombozoa (dicyemids) Subregnum Eumetazoa Radiata (unranked) (radial symmetry) Ctenophora (comb jellies) Cnidaria (coral, jellyfish, anemones) Bilateria (unranked) (bilateral symmetry) Acoelomorpha (basal) Myxozoa (slime animals) Superphylum Deuterostomia (blastopore becomes anus) Chordata (vertebrates, etc. ... Wind turbines A machine is any mechanical or organic device that transmits or modifies energy to perform or assist in the performance of tasks. ... Latin is an ancient Indo-European language. ...

An ostrich, one of the fastest of living bipeds
An ostrich, one of the fastest of living bipeds
A Man Running - Edward Muybridge
A Man Running - Edward Muybridge

Contents

Ostrich in Tanzania; from German Wikipedia, in the public domain File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Ostrich in Tanzania; from German Wikipedia, in the public domain File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Binomial name Struthio camelus Linnaeus, 1758 The ostrich (Struthio camelus) is a flightless bird native to Africa. ... Nude Man Running - Edward Muybridge This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Nude Man Running - Edward Muybridge This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... The Horse in Motion Eadweard Muybridge (April 9, 1830 – May 8, 1904) was a British-born photographer, known primarily for his early use of multiple cameras to capture motion. ...


Diversity and evolution of bipedalism

Types of bipedal movement

There are a number of states of movement commonly associated with bipedalism.


1. Standing. Staying still on both legs. In most bipeds this is an active process, requiring constant adjustment of balance. In law, standing or locus standi is the ability of a party to demonstrate to the court sufficient connection to and harm from the law or action challenged. ...


2. Walking. One foot in front of another, with at least one foot on the ground at any time. Woman walking downstairs Walk redirects here. ...


3. Running. One foot in front of another, with periods where both feet are off the ground. This article or section does not cite its references or sources. ...


4. Hopping. Moving by a series of jumps with both feet moving together. Jumping Freighthopping Island hopping Movie hopping This is a disambiguation page: a list of articles associated with the same title. ...


Bipedal animals

Bipedal movement has evolved a number of times other than in humans, mostly among the vertebrates. The most obvious example of bipedal movement is among the birds and their ancestors the theropod dinosaurs. All dinosaurs are believed to be descended from a fully bipedal ancestor, perhaps similar to Eoraptor. Indeed, among their descendants, the larger flightless birds, the ratites, such as the ostrich, perhaps epitomise the capacity to move bipedally, able to reach speeds of up to 65 km/h. Likewise many theropod dinosaurs, especially the maniraptors, are believed to have been able to move at similar speeds. Bipedal movement also re-evolved in a number of other dinosaur lineages such as the iguanodons. Some extinct members of the crocodilian line, a sister group to the dinosaurs and birds, have aso evolved bipedal forms - a crocodile relative from the triassic, Effigia okeeffeae, was believed to be bipedal [1]. Larger birds tend to walk with alternating legs, whereas smaller birds will often hop. Penguins are interesting birds with regard to bipedality as they tend to hold their bodies upright, rather than horizontal as in other birds. Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ... Classes and Clades Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. ... Orders Many - see section below. ... Families See text Theropods (beast foot) are a group of bipedal, primarily carnivorous dinosaurs, belonging to the saurischian (lizard-hip) family. ... Binomial name Eoraptor lunensis Sereno et al, 1993 Eoraptor was one of the worlds earliest dinosaurs. ... Families Struthionidae Casuariidae Dinornithidae Apterygidae Rheidae A ratite is any of a diverse group of large, flightless birds of Gondwanian origin, most of them now extinct. ... Binomial name Struthio camelus Linnaeus, 1758 The ostrich (Struthio camelus) is a flightless bird native to Africa. ... Maniraptora is a group used in biological classification to cover the birds and the dinosaurs that were related to them. ... Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... Species (neotype) (holotype) Iguanodon is a genus of ornithopod dinosaurs. ... Suborders Eusuchia Protosuchia † Mesosuchia † Sebecosuchia † Thalattosuchia † Crocodilia is an order of large reptiles that scientists believe branched off from class Reptilia about 220 million years ago. ... Genera Mecistops Crocodylus Osteolaemus See full taxonomy. ... The Triassic is a geologic period that extends from about 245 to 202 Ma (million years ago). ... Effigia okeeffeae was an archosaur that lived in what is now New Mexico. ... Modern Genera Aptenodytes Eudyptes Eudyptula Megadyptes Pygoscelis Spheniscus For extinct genera, see Systematics Penguins (order Sphenisciformes, family Spheniscidae) are an order of aquatic, flightless birds living in the Southern Hemisphere. ...


Bipedal movement is less common among mammals, most being quadrupedal. The largest mammalian group using bipedal movement are the kangaroos and their relatives. However these tend to move mostly by hopping, which is quite different from humans and many birds. There are also various groups of hopping rodents, such as the kangaroo rats. A primate, the sifaka, also moves by hopping when on the ground. Possibly the only mammals other than humans that commonly moves bipedally by an alternating gait rather than hopping are gibbons when on the ground, and giant pangolins. Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Eutheria (excludes extinct ancestors) Afrosoricida Anagaloidea (extinct) Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata (extinct) Perissodactyla Pholidota Plesiadapiformes... The Zebra is an example of a quadruped. ... Species Macropus rufus Macropus giganteus Macropus fuliginosus A kangaroo is any of several large macropods (the marsupial family that also includes the wallabies, tree-kangaroos, wallaroos, pademelons and the Quokka: 65 species in all). ... Species 22, see text Kangaroo rats, genus Dipodomys, are small rodents native to North and Central America. ... Type species Propithecus diadema Bennett, 1832 Species Propithecus diadema Propithecus edwardsi Propithecus perrieri Propithecus tattersalli Propithecus verreauxi Propithecus coquereli Propithecus deckenii Sifakas are a genus (Propithecus) from the primate family Indridae. ... Genera Hylobates Hoolock Nomascus Symphalangus Gibbons are the small apes that are grouped in the family Hylobatidae. ... Binomial name Manis gigantea , The Giant Pangolin is the largest species of pangolin, found in Africa. ...


Limited examples of bipedalism are found in some other mammals. For example the bonobo ape and proboscis monkey, who both live in forests that are often flooded, will wade through water in a bipedal stance. On occasion bonobos and proboscis monkeys, and less frequently some other primates, will also walk or stand bipedely on land. A number of other animals, such as rats, will squat on their hindlegs in order to manipulates food objects. The raccoon often stands erect or squats in water to use its hands to manipulate food and rocks/sticks. Beavers will also move bipedally at times when carrying branches. Some animals, such as the bear, may raise up and move bipedally during physical confrontation, so as to better be able to use their forelegs as weapons. Also a number of mammals, such as ground squirrels or meerkats will stand on their hind legs, but not walk on them, in order to survey their surroundings. Finally, gerenuk antelope are known to stand on their hind legs in order to eat leaves from trees. The extinct giant ground sloth had hip joints whose form indicates that they also did this. Another extinct group, the bizarre rhino/gorilla-like chalicotheres may also have behaved similarly. One unusual form of limited bipedalism is the spotted skunk which when threatened stands on its forelimbs, allowing it to direct its anal glands, which can fire an offensively odorous oil, towards an attacker while still facing the attacker. Binomial name Pan paniscus Schwarz, 1929 The Bonobo (Pan paniscus), until recently usually called the Pygmy Chimpanzee and less often the Dwarf or Gracile Chimpanzee, is one of the two species comprising the chimpanzee genus, Pan. ... Binomial name Nasalis larvatus (Wurmb, 1787) The Proboscis Monkey (Nasalis larvatus, monotypic in genus Nasalis) is a reddish-brown arboreal leaf-eating monkey, found only in the coastal areas of Borneo and the Mentawai Islands west of Sumatra, in coastal mangrove swamps and riverine forests. ... Families 15, See classification A primate (L. prima, first) is any member of the biological order Primates, the group that contains all the species commonly related to the lemurs, monkeys, and apes, with the latter category including humans. ... Species 50 species; see text *Several subfamilies of Muroids include animals called rats. ... Type Species Procyon lotor Linnaeus, 1758 Species Procyon cancrivorus Procyon insularis Procyon lotor Raccoons are nocturnal mammals in the genus Procyon of the Procyonidae family. ... Species C. canadensis C. fiber Beavers are semi-aquatic rodents native to North America and Europe. ... Genera Ailuropoda Ailurus Helarctos Melursus Ursus Tremarctos Arctodus (extinct) A bear is a large mammal in the family Ursidae of the order Carnivora. ... Genera Many: see text. ... Binomial name Suricata suricatta (Schreber, 1776) The meerkat or suricate, is a small reptile and a member of the mongoose family. ... Binomial name Litocranius walleri (Brooke, 1878) The Gerenuk (Litocranius walleri) is an antelope-like animal, closely related to the gazelle, found in East Africa. ... Families Rathymotheriidae Scelidotheriidae Mylodontidae Orophodontidae Megalonychidae Megatheriidae Ground sloths are extinct edentate (Order Xenarthra) mammals that are believed to be relatives of tree sloths and three-toed sloths. ... The Rhinoceros is a large land animal. ... Type Species Troglodytes gorilla Savage, 1847 Species Gorilla gorilla Gorilla beringei The gorilla, the largest of the living primates, is a ground-dwelling herbivore that inhabits the forests of Africa. ... Chalicotheres were a group of perissodactyl mammals that lived from 45 to 3. ... Species Spilogale gracilis Merriam, 1890 Spilogale putorius (Linnaeus, 1758) Spilogale pygmaea Thomas, 1898 The Eastern Spotted Skunk (Spilogale putorius) of the family Mephitidae is smaller and more weasel-like than the striped skunk. ...


Among the non-archosaur reptiles bipedalism is rare, and it is unknown among the amphibians, however it its found in the "reared-up" running of certain lizards. An interesting example is found in at least one genus of basilisk lizard that by this method can run across the surface of water for some distance. Bipedalism in the form of reared-up running can also be found in some insects such as the cockroach. Otherwise bipedal movement is unknown in arthropods. Bipeds are almost exclusively terrestrial animals. However, at least two types of octopus are known to walk bipedally. This form of locomotion appears to allow them to remain somewhat camouflaged while moving quickly, taking a form like a coconut or seaweed and moving on the tips of two of its arms.-1... Orders See text. ... Subclasses and Orders Order Temnospondyli- extinct Subclass Lepospondyli- extinct Subclass Lissamphibia   Anura   Caudata   Gymnophiona Amphibians (class Amphibia) are a taxon of animals that include all tetrapods (four-legged vertebrates) that do not have amniotic eggs. ... Families Many, see text. ... Species Basiliscus basiliscus Basiliscus galeritus Basiliscus plumifrons Basiliscus vittatus Basiliscus is a genus of lizards that includes the basilisks. ... Classes & Orders See taxonomy Insects are invertebrate animals of the Class Insecta, the largest and (on land) most widely-distributed taxon within the phylum Arthropoda. ... Families Blaberidae Blattellidae Blattidae Cryptocercidae Polyphagidae Nocticolidae Cockroaches are insects of the Order Blattodea. ... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - trilobites (extinct) Subphylum Chelicerata Arachnida - spiders,scorpions, etc. ... Animal environments are classified as either aquatic (water), terrestrial (land), or amphibious (water and land). ... Families 14 in two suborders, see text. ...


Exceptional cases

Many animals that do not use bipedal locomotion in nature can be trained to walk on hind legs. Animals missing limbs due to injury or congenital deformity may adapt to bipedal motion, either on two hind legs or on one front and one back leg. For videos of both kinds of bipedal motion in dogs see [2] and [3]. Some unusual individual primates have also been known to be bipedal. There has been one recorded case of a macaque switching to bipedal walking completely after recovering from a serious illness [4], and at least one example of a captive chimp who only walked upright, Oliver. Some animals can also be trained to walk on front limbs. Humans too, can learn to walk using solely their arms (see handstand and hand walking). A biped is an animal that travels across surfaces supported by two legs. ... Oliver is a chimpanzee who was once promoted as a missing link due to his bipedal walk. ... Woodcut from the 16th century. ... Hand walking is an unusual form of locomotion, in which the walker moves primarily using their hands. ...


Advantages

Bipedalism and associated traits can offer a species several advantages:

  • Improved perception. Some evolutionary biologists have suggested that a crucial stage in the evolution of some or all bipeds was the ability to stand, which generally improves the ability to see (and perhaps otherwise detect) distant dangers or resources.
  • Free forelimbs. In vertebrate species, for whom evolution of additional limbs would be an enormous genetic change, it can serve to free the front limbs for such other functions as manipulation (in primates), flight (in birds), digging (giant pangolin), or combat (bears).
  • Wading. Raccoons and some primates may adopt a bipedal position in water, allowing them to stand or walk in deeper water while still breathing air.
  • Faster speed. In animals without a flexible backbone, such as lizards or cockroaches, bipedalism may increase running speed. However the maximum bipedal speed appears less fast than the maximum speed of quadrapedal movement with a flexible backbone - compare the fastest bipeds the ostrich (65 km/h) or the red kangaroo (70 km/h) with the fastest quadruped, the cheetah ( 103 km/h).
  • Greater reach. Gerunuk antelope adopt a bipedal position to browse the leaves from trees.
  • Camouflage. It has been speculated that bipedalism in octopuses allows them to move while keeping the rest of their bodies still for camouflage.
  • Face attacker while directing anal glands. The defense posture of the spotted skunk, which involves walking on its forelimbs, allows the skunk to face the attacker while simultaneously directing its anal glands at them. The anal glands can squirt an offensive smelling oil.

For the animated television series see The Raccoons Binomial name Procyon lotor (Linnaeus, 1758) The Common Raccoon (Procyon lotor), often just called the Raccoon, is a mammal native to America. ... Binomial name Struthio camelus Linnaeus, 1758 The ostrich (Struthio camelus) is a flightless bird native to Africa. ... Binomial name Macropus rufus Desmarest, 1822 The Red Kangaroo (Macropus rufus) is the largest of all kangaroos and the largest surviving marsupial. ... The Zebra is an example of a quadruped. ... Binomial name Acinonyx jubatus (Schreber, 1775) The Cheetah (from Hindi चीता cītā, derived from Sanskrit word chitraka meaning Speckled) (Acinonyx jubatus) is an atypical member of the cat family (Felidae) that hunts by speed rather than by stealth or pack tactics. ...

Evolution

Humans

There are many hypotheses as to how and why bipedalism evolved in humans, and also some debate as to when. Evidence points to bipedalism evolving before the expansion in human brain size. The different hypotheses are not necessarily mutually exclusive and a number of selective forces may have acted together to lead to human bipedalism.


Postural Feeding Hypothesis


The postural feeding hypothesis has been recently supported by Dr. Kevin Hunt, a professor at Indiana University. This theory asserts that chimpanzees were only bipedal when they ate. While on the ground, they would reach up for fruit hanging from small trees and while in trees, bipedalism was utilized by grabbing for an overhead branch. These bipedal movements may have evolved into regular habits because they were so convenient in obtaining food. Also, Hunt theorizes that these movements coevolved with chimpanzee arm-hanging, as this movement was very effective and efficient in harvesting food. When analyzing fossil anatomy, Australopithecus afarensis has very similar features of the hand and shoulder to the chimpanzee, which indicates hanging arms. Also, the Australopithecus hip and hind limb very clearly indicate bipedalism, but these fossils also indicate very inefficient locomotive movement when compared to humans. For this reason, Hunt argues that bipedalism evolved more as a terrestrial feeding posture than as a walking posture. As Hunt says, “A bipedal postural feeding adaptation may have been a preadaptation for the fully realized locomotor bipedalism apparent in Homo erectus.” Type Species Simia troglodytes Blumenbach, 1775 Species Pan troglodytes Pan paniscus Chimpanzee, often shortened to chimp, is the common name for the two extant species in the genus Pan. ... Binomial name †Australopithecus afarensis Johanson & White, 1978 Australopithecus afarensis is a hominid which lived between 3. ... Species †A. afarensis (Lucy) †A. africanus †A. anamensis †A. bahrelghazali †A. garhi Formerly Australopithecus, now Paranthropus † † † The gracile australopithecines (members of the genus Australopithecus) are a group of extinct hominids that are closely related to humans. ... Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ...


Behavioral Model


One of the most elaborative theories on the origin of bipedalism is the behavior model presented by C. Owen Lovejoy. Lovejoy theorizes that the evolution of bipedalism was a response to a monogamous society. As hominid males became monogamous, they would leave their families for the day in order to search for food. Once they found food for their family, the hominids would have to bring back the food and the most effective way of doing this was through bipedalism. Because this theory is complex, many criticisms arise. First, all evidence indicates that early hominids, which are proven to be bipedal, were polygamous. Second, among all monogamous primates, sexual dimorphism is mostly absent, but in Australopithecus afarensis males were found to be nearly twice the weight of females, an attribute scientists would expect in a polygamous species. Lastly, monogamous primates are highly territorial, but fossil evidence indicates that Australopithecus afarensis lived in large groups. This theory has too much evidence going against it for it to be considered a viable origin of bipedalism. A hypothetical phylogenetic tree of all extant organisms, based on 16S rRNA gene sequence data, showing the evolutionary history of the three domains of life, bacteria, archaea and eukaryotes. ... Genera Subfamily Ponginae Pongo - Orangutans Gigantopithecus (extinct) Sivapithecus (extinct) Lufengpithecus (extinct) Ankarapithecus (extinct) Subfamily Homininae Gorilla - Gorillas Pan - Chimpanzees Homo - Humans Dryopithecus (extinct) Ouranopithecus (extinct) Paranthropus (extinct) Australopithecus (extinct) Sahelanthropus (extinct) Orrorin (extinct) Ardipithecus (extinct) Kenyanthropus (extinct) Pierolapithecus (extinct) (tentative) The hominids are the members of the biological family Hominidae... Female (left) and male Common Pheasant, illustrating the dramatic difference in form between the sexes Sexual dimorphism is the systematic difference in form between individuals of different sex in the same species. ...


Thermoregulatory Model


The thermoregulatory model explaining the origin of bipedalism is one of the simplest theories on the table, but it is a viable explanation. Dr. Peter Wheeler, a professor of evolutionary biology, proposes that bipedalism raises the amount of body surface area higher above the ground which results in a reduction in heat gain helps heat dissipation. When a hominid is higher above the ground, the organism accesses more favorable wind speeds and temperatures. During heat seasons, greater wind flow results in a higher heat loss, which makes the organism more comfortable. Also, Wheeler explains that a vertical posture minimizes the direct exposure to the sun whereas quadrupedalism exposes more of the body to direct exposure.


Wading Hypothesis


This theory proposes that humans evolved bipedalism as a result of bipedal wading. Bipedal wading is found among the semi-bipedal wading cousins of humans, the bonobo chimps, the lowland gorillas, and proboscis monkeys. Bipedal wading provides the advantage of keeping the head above water for breathing. This theory is part of a general theory of human evolution which often goes by the name of the aquatic ape hypothesis. Kuliakas 2001 argues that the skeletal morphology of the early hominan Australopithecus afarensis is consistent with adaptation for wading in water. Binomial name Pan paniscus Schwarz, 1929 The Bonobo (Pan paniscus), until recently usually called the Pygmy Chimpanzee and less often the Dwarf or Gracile Chimpanzee, is one of the two species comprising the chimpanzee genus, Pan. ... Type Species Troglodytes gorilla Savage, 1847 Species Gorilla gorilla Gorilla beringei The gorilla, the largest of the living primates, is a ground-dwelling herbivore that inhabits the forests of Africa. ... Binomial name Nasalis larvatus (Wurmb, 1787) The Proboscis Monkey (Nasalis larvatus, monotypic in genus Nasalis) is a reddish-brown arboreal leaf-eating monkey, found only in the coastal areas of Borneo and the Mentawai Islands west of Sumatra, in coastal mangrove swamps and riverine forests. ... The aquatic ape hypothesis (or aquatic ape theory as it is frequently called) is most commonly interpreted to hold that ancestors of humans and other hominids went through one or more periods of time living in a semi-aquatic setting on an African seacoast, that they gathered most of their... Genera Homo (humans) Paranthropus (extinct) Australopithecus (extinct) Sahelanthropus (extinct) Orrorin (extinct) Ardipithecus (extinct) Kenyanthropus (extinct) The more anthropomorphic primates of the Hominini tribe are placed in the Hominina subtribe. ... Binomial name †Australopithecus afarensis Johanson & White, 1978 Australopithecus afarensis is a hominid which lived between 3. ...


Turn-Over Pulse Hypothesis


The theory is part of a general theory of human evolution known as the savanna hypothesis. This theory asserts that a major climate change occurred which induced an onset of drier conditions. These dry conditions severely reduced the amount of wooded habitats in the Pliocene era, about 2.5 million years ago. During this period where the forests became thin, the Australopithecus organisms had to evolve and change their habitats from the forest to grasslands. In order to remain effective in gathering food, the hominids had to travel long distances with food or tools, thus making quadrupedalism extremely inefficient. These hominids evolved into bipeds which made their treks along the grasslands much more efficient. It was commonly believed that early hominids left the jungle to live on the open plains of Africa. ... The Pliocene epoch (spelled Pleiocene in some older texts) is the period in the geologic timescale that extends from 5. ...


References

  • Kuliukus, A., "Wading for Food: The Driving Force of the Evolution of Bipedalism." Nutrition and Health, 16(4), 267-290, (2002). html

Physiology of bipedalism

Bipedal movement occurs in a number of ways, and requires many mechanical and neurological adaptations. Some of these are described below.


Biomechanics

Engineers who study bipedal walking or running describe it as a repeatedly interrupted fall. The phenomenon of "tripping" is informative with regards to the "controlled falling" concept of walking and running. The common way to think of tripping is as pulling a leg out from under a walker or runner. In fact, however, merely stopping the movement of one leg of a walker, and merely slowing one leg of a runner, is sufficient to amount to tripping them. They were already "falling", and preventing the tripped leg from aborting that fall is sufficient to cause bipeds to collapse to the ground.

  • Standing

Energy-efficient means of standing bipedally involve constant adjustment of balance, and of course these must avoid overcorrection. Feedback is (generally) information about actions. ...

  • Walking

Efficient walking is more complicated than standing. It entails tipping slightly off-balance forward and to the side, and correcting balance with the right timing. In humans, walking is composed of several separate processes:

  • rocking back and forth between feet
  • pushing with the toe to maintain speed
  • combined intruption in rocking and ankle twist to turn
  • shortening and extending the knees to prolong the "forward fall"
  • Running

Running is an inherently continuous process, in contrast to walking; a bipedal creature or device, when efficiently running, is in a constant state of falling forward. This is maintained as relatively smooth motion only by repeatedly "catching oneself" with the right timing, but in the case of running only delaying the nearly inevitable fall for the duration of another step.

  • Hopping

Musculature

Bipedalism requires strong leg muscles, particularly in the thighs. Contrast in domesticated poultry the well muscled legs, against the small and bony wings. Likewise in humans, the quadriceps and hamstring muscles of the thigh are both so crucial to bipedal activities that each alone is much larger than even the well-developed biceps of the arms. Domesticated animals, plants, and other organisms are those whose collective behavior, life cycle, or physiology has been altered as a result of their breeding and living conditions being under human control for multiple generations. ... Ducks amongst other poultry The Poultry-dealer, after Cesare Vecellio. ... Muscles of the iliac and anterior femoral regions. ... Hamstring refers to the common tendon of the muscles making up the ham in animals, primarily the semitendinosus and biceps femoris. ...


Nervous system

The famous knee jerk (or patellar reflex) emphasizes the necessary bipedal control system: the only function served by the nerves involved being connected as they are is to ensure quick response to imminent disturbance of erect posture; it not only occurs without conscious mental activity, but also involves none of the nerves which lead from the leg to the brain. The patellar reflex is a reflex employing only three neurons. ...


A less well-known aspect of bipedal neuroanatomy can be demonstrated in human infants who have not yet developed toward the ability to stand up. They can nevertheless run with great dexterity, provided they are supported in a vertical position and offered the stimulus of a moving treadmill beneath their feet. Neuroanatomy is the anatomy of the nervous system. ...


Respiration

A biped also has the ability to breathe whilst it runs. Humans usually take a breath every other stride when their aerobic system is functioning. During a sprint, at which point the anaerobic system kicks in, breathing slows until the anaerobic system can no longer sustain a sprint. Look up Aerobic in Wiktionary, the free dictionary. ... Look up Anaerobic in Wiktionary, the free dictionary. ...


Bipedal robots

Main article: humanoid robot
ASIMO - a bipedal robot
ASIMO - a bipedal robot

For nearly the whole of the 20th century, bipedal robots were very difficult to construct. Robots which could move usually did so using wheels, treads, or multiple legs (see robot locomotion). Increasingly cheap and compact computing power, however, has made two-legged robots more feasible. Two notable biped robots are ASIMO, developed by Honda, and QRIO, developed by Sony. A humanoid robot is a robot with its overall appearance based on that of the human body. ... ASIMO File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... ASIMO File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... ASIMO ASIMO is a humanoid robot created in 2000 by Honda. ... (19th century - 20th century - 21st century - more centuries) Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s As a means of recording the passage of time, the 20th century was that century which lasted from 1901–2000 in the sense of the Gregorian calendar (1900–1999 in the... ASIMO, a humanoid robot manufactured by Honda. ... Robot locomotion is the study of how to design robot appendages and control mechanisms to allow robots to move fluidly and efficiently. ... ASIMO ASIMO is a humanoid robot created in 2000 by Honda. ... For other uses, see Honda (disambiguation). ... QRIO QRIO (Quest for cuRIOsity, originally named Sony Dream Robot or SDR) was to be bipedal humanoid entertainment robot marketed and sold by Sony to follow up on the success of its AIBO toy. ... This article or section does not cite its references or sources. ...


External links

  • Study pushes bipedalism back 2 million years
  • Information about bipedal octopuses, with link to original paper and videos
  • Why australopithecines became bipedal
  • Time-warp family who walk on all fours
  • The dawn of man, article on the evolution of bipedalism
  • Comparative bipedalism - how the rest of the animal kingdom walks on two legs
  • Video of Faith, a dog born without her front legs and trained to walk upright
  • Video of Dominic, a greyhound adapted to non-upright bipedal motion after losing both right legs
  • Video of Honda's humanoid robot Asimo running (Dec 16 2004)
  • Albert Einstein Hubo: by Hanson Robotics and KAIST

  Results from FactBites:
 
Biped - Wikipedia, the free encyclopedia (2456 words)
In most bipeds this is an active process, requiring constant adjustment of balance.
Some evolutionary biologists have suggested that a crucial stage in the evolution of some or all bipeds was the ability to stand, which generally improves the ability to see (and perhaps otherwise detect) distant dangers or resources.
They were already "falling", and preventing the tripped leg from aborting that fall is sufficient to cause bipeds to collapse to the ground.
biped (14466 words)
Bifurcation diagrams of the periodic motions of the biped are used to demonstrate the improvements in controller performance that arise from the application of the proposed method.
Scaling laws for the model predict that walking speed is proportional to stance angle, stance angle is proportional to gamma(1/3), and that the gravitational power used is proportional to upsilon(4) where upsilon is the velocity along the slope.
Physical admissibility of the biped trajectory is characterized in terms of the equivalent force-moment and zero-moment point.
  More results at FactBites »

 
 

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