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 6, eight or more limbs with the podials and metatarsals The metatarsus consists of the five long bones of the foot, which are numbered from the medial side ; each presents for examination a body and two extremities. These are analogous to the metacarpus bones of the hand 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). They are generally quicker and move more quietly than other mammals, walking on the toes Toes are the digits of the foot of an animal. 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 the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; (2) 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 A nail is a horn-like structure at the end of a person's finger or toe. The nail is generally regarded as a distinctively primate feature. Although it is not a feature confined exclusively to primates, the development of nails is extremely rare in other mammals. See also claw or nails of the toes (the hoof Most even-toed ungulates have two main hooves on each foot, together called a cloven hoof. Most of these cloven-hoofed animals also have two smaller hoofs called dew-claws a little further up the leg – these are not normally used for walking, but in some species with larger dew-claws (such as deer and pigs) they may touch the ground when running) 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 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 a long bone, 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 consists of the five long bones of the foot, which are numbered from the medial side ; each presents for examination a body and two extremities. These are analogous to the metacarpus bones of the hand/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 tarsals/carpals In tetrapods, the carpus is the sole cluster of bones in the wrist between the radius and ulna and the metacarpus. The bones of the carpus do not belong to individual fingers , whereas those of the metacarpus do. The corresponding part of the foot is the tarsus. The carpal bones allow the wrist to move and rotate vertically, the finger and toe bones.
Humans Humans are bipedal primates belonging to the species Homo sapiens in Hominidae, the great ape family. They are the only surviving members of the genus Homo. Humans have a highly developed brain, capable of abstract reasoning, language, introspection, and problem solving. This mental capability, combined with an erect body carriage that frees the are an example of a plantigrade species. Other plantigrade species include (but are not limited to) raccoons The raccoon , sometimes spelled as racoon, and also known as the common raccoon, North American raccoon, northern raccoon and colloquially as coon, is a medium-sized mammal native to North America. As a result of escapes and deliberate introductions in the mid-20th century, raccoons are now also distributed across the European mainland, the, opossums Didelphimorphia is the order of common opossums of the Western Hemisphere. They are commonly also called possums, though that term is also applied to Australian fauna of the suborder Phalangeriformes. The Virginia Opossum is the original animal named opossum. The word comes from Algonquian wapathemwa. Opossums probably diverged from the basic, 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 continent 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. The American white-footed mouse (Peromyscus leucopus) and the deer mouse (Peromyscus maniculatus) also sometimes live in houses. In some places, certain kinds of field mice are also common, 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 or muscular hypertonicity is a disorder of the central nervous system in which certain muscles continually receive a message to tighten and contract. The nerves leading to those muscles, unable to regulate themselves (which would provide for normal muscle tone), permanently and continually "over-fire" these commands to tighten, 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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