In terrestrial animals Animals are a major group of mostly multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and independently. All animals are also, plantigrade locomotion means walking Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step. This applies regardless of the number of limbs - even arthropods with six, eight or more limbs with the podials and metatarsals The metatarsus or metatarsal bones are a group of five long bones in the foot located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the medial side : the first, second, third, fourth, and fifth metatarsal. The metatarsals are analogous to the flat on the ground. It is one of three forms of locomotion adopted by mammals. The other options are digitigrade A digitigrade is an animal that stands or walks on its digits, or toes. Digitigrades include walking birds , cats, dogs, and most other mammals, but not humans, bears, and a few others (cf. plantigrade, unguligrade). Digitigrades are generally quicker and move more quietly than other mammals, walking on the toes Toes are the digits of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being digitigrade. Humans, and other animals that walk on the soles of their feet, are described as being plantigrade; unguligrade animals are those that walk on hooves at the tips of their toes. The toes are, from medial to lateral: with the heel In human anatomy, the heel is the prominence at the posterior end of the foot. It is based on the projection of one bone, the calcaneus or heel bone, behind the articulation of the bones of the lower leg and wrist In human anatomy, the wrist is variously defined as 1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; the wrist joint or radiocarpal joint, the joint between the radius and the carpus; and (3) the anatomical region surrounding the carpus including the distal parts of the bones of the permanently raised, and unguligrade Ungulates are several groups of mammals, most of which use the tips of their toes, usually hoofed, to sustain their whole body weight while moving. They make up several orders of mammals, of which six to eight survive. There is some dispute as to whether Ungulata are a cladistic (evolution-based) group, or merely a phenetic group or folk taxon (, walking on the nail In human anatomy, a nail is a horn-like envelop covering the dorsal aspect of the terminal phalanges of fingers and toes. Nails are also present in several other primates. Although not exclusive to primates, the development of nails is extremely rare in other mammals or nails of the toes (the hoof A hoof is the tip of a toe of an ungulate mammal, strengthened by a thick horny covering. The hoof consists of a hard or rubbery sole, and a hard wall formed by a thick nail rolled around the tip of the toe. The weight of the animal is normally borne by both the sole and the edge of the hoof wall. Hooves grow continuously, and are constantly worn) with the heel/wrist and the digits A digit is one of several most distal parts of a limb, such as fingers or toes, present in many vertebrates permanently raised. The leg of a plantigrade mammal includes the bones of the upper leg (femur The femur, or thigh bone, is the most proximal bone of the leg in vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in the rear legs/humerus The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow) and lower leg (tibia The tibia, shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones. The tibia is named for the greek aulos flute, also known as a tibia. It is commonly recognised as the strongest weight bearing bone in the body and fibula The fibula or calf bone is a bone located on the lateral side of the tibia, with which it is connected above and below. It is the smaller of the two bones, and, in proportion to its length, the most slender of all the long bones. Its upper extremity is small, placed toward the back of the head of the tibia, below the level of the knee-joint, and/radius In classical geometry, a radius of a circle or sphere is any line segment from its center to its perimeter. By extension, the radius of a circle or sphere is the length of any such segment, which is half the diameter and ulna The ulna is one of the two long bones in the forearm, prismatic in form. In anatomical position the ulna is placed at the medial side of the forearm closest to the body, parallel with the radius on both arms). The leg of a digitigrade mammal also includes the metatarsals The metatarsus or metatarsal bones are a group of five long bones in the foot located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the medial side : the first, second, third, fourth, and fifth metatarsal. The metatarsals are analogous to the/metacarpals In human anatomy, the metacarpus is the intermediate part of the hand skeleton that is located between the phalanges distally and the carpus which forms the connection to the forearm. The metacarpus consists of metacarpal bones. Its equivalent in the foot is the metatarsus, the bones that in a human compose the arch of the foot and the palm of the hand. The leg of an unguligrade mammal also includes the phalanges In anatomy, phalanx bones are those that form the fingers and toes. In primates such as humans and monkeys, the thumb and big toe have two phalanges, while the other fingers and toes consist of three. Phalanges are classified as long bones, the finger and toe bones.
Humans Humans, known taxonomically as Homo sapiens , are the only living species in the Homo genus of bipedal primates in Hominidae, the great ape family. However, in some cases "human" is used to refer to any member of the genus Homo are an example of a plantigrade species. Other plantigrade species include (but are not limited to) raccoons The raccoon (pronounced /ræˈkuːn/ , Procyon lotor), sometimes spelled as racoon, also known as the common raccoon, North American raccoon, northern raccoon and colloquially as coon, is a medium-sized mammal native to North America. It is the largest of the procyonid family, having a body length of 40 to 70 cm (16 to 28 in) and a body weight of 3, opossums Opossums are the largest order of marsupials in the Western Hemisphere. They are also commonly called possums, though that term is also applied to Australian fauna of the suborder Phalangeriformes. The Virginia Opossum was the first animal to be named an opossum.[citation needed] The word opossum comes from Algonquian wapathemwa meaning ", bears Bears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives. Although there are only eight living species of bear, they are widespread, appearing in a wide variety of habitats throughout the Northern Hemisphere and partially in the Southern Hemisphere, kangaroo A kangaroo is a marsupial from the family Macropodidae . In common use the term is used to describe the largest species from this family, especially those of the genus Macropus, Red Kangaroo, Antilopine Kangaroo, Eastern Grey Kangaroo and Western Grey Kangaroo. Kangaroos are endemic to the country of Australia. The smaller macropods are found in, mice A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse (Mus musculus). It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles. They are known to invade homes for food and occasionally shelter, pandas The Red Panda is a small arboreal mammal and the only species of the genus Ailurus. Slightly larger than a domestic cat, it has reddish-brown fur, a long, shaggy tail, and a waddling gait due to its shorter front legs. It eats mainly bamboo, but is omnivorous and may also eat eggs, birds, insects, and small mammals. It is a solitary animal, mainly, rats Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus. Many members of other rodent genera and families are also referred to as rats, and share many, hyraxes, skunks Skunks are mammals best known for their ability to secrete a liquid with a strong, foul-smelling odor. General appearance ranges from species to species, from black-and-white to brown or cream colored. Skunks belong to the family Mephitidae and to the order Carnivora. There are 10 species of skunks, which are divided into four genera: Mephitis , and hedgehogs A hedgehog is any of the spiny mammals of the subfamily Erinaceinae and the order Erinaceomorpha. There are 17 species of hedgehog in five genera, found through parts of Europe, Asia, Africa, and New Zealand. There are no hedgehogs native to Australia, and no living species native to North America; those in New Zealand are introduced. Hedgehogs. The primary advantages of a plantigrade foot are stability and weight-bearing ability; plantigrade feet have the largest surface area. The primary disadvantage of a plantigrade foot is speed. With more bones and joints in the foot, the leg is both shorter and heavier at the far end, which makes it difficult to move rapidly.
Among extinct animals, most early mammals such as pantodonts were plantigrade. A plantigrade foot is the primitive condition for mammals; digitigrade and unguligrade locomotion evolved later. Among archosaurs, the pterosaurs Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period (220 to 65.5 million years ago). Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the legs were partially plantigrade, walking on the whole of the hind foot and the fingers of the hand-wing.
Plantigrade foot occurs normally in humans in static postures of standing Standing is a human position in which the body is held upright and supported only by the feet, referred to as an orthostatic state and sitting Sitting is a rest position supported by the buttocks or thighs where the torso is more or less upright. There are several ways for humans to sit. It should also occur normally in gait Gait is the pattern of movement of the limbs of animals, including humans, during locomotion over a solid substrate. Most animals use a variety of gaits, selecting gait based on speed, terrain, the need to maneuver, and energetic efficiency. Different animal species may use different gaits due to differences in anatomy that prevent use of certain (walking). Hypertonicity, spasticity Spasticity is a feature of altered skeletal muscle performance, occurring in disorders of the central nervous system which give rise to the Upper Motor Neuron Syndrome. Muscles affected by the Upper Motor Neuron Syndrome have many other potential features of altered performance including weakness, decreased motor control, clonus (a series of, clonus Clonus is a series of involuntary muscular contractions due to sudden stretching of the muscle. Clonus is a sign of certain neurological conditions, and is particularly associated with upper motor neuron lesions such as in stroke, multiple sclerosis, spinal cord damage and hepatic encephalopathy. Unlike the small, spontaneous twitching known as, limited range of motion, abnormal flexion neural pattern, and a plantarflexor (calf) muscle contracture may contribute to an individual only standing and/or walking on his toes. This would be evident by the observable heel rise.
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Thu, 24 Jun 2010 07:23:27 GMT+00:00
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