Plantigrade

 ( Terrestrial Locomotion ) 

In terrestrial , plantigrade locomotion means walking with the toes and flat on the ground. It is one of three forms of locomotion adopted by terrestrial . The other options are digitigrade, walking on the and fingers with the heel and wrist permanently raised, and ungulate, walking on the nail or nails of the toes (the hoof) with the heel/wrist and the digits permanently raised. The leg of a plantigrade mammal includes the bones of the upper leg (femur/humerus) and lower leg (tibia and fibula/radius and ulna). The leg of a digitigrade mammal also includes the /, 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, the finger and toe bones.

Among extinct animals, most early mammals such as Pantodonta were plantigrade. A plantigrade foot is the primitive condition for mammals; digitigrade and unguligrade locomotion evolved later. Among archosaurs, the pterosaurs were partially plantigrade and walked on the whole of the hind foot and the fingers of the hand-wing. Out of the plantigrade animals, only a few, such as humans, kangaroos and certain rodents, are obligate Bipedalism, while most others are functional bipeds.

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List of plantigrade animals Plantigrade animals species include (but are not limited to):

• Several (including humans and )
• Carnivora:
• Bear: bears
• Amphicyonidae
• Musteloidea: , , , , , and
• Barbourofelis: false saber-tooth cats
• Rodents: mice, ,
• Hyrax
• Marsupialia: ,
• Nearly all basal mammals and non-mammalian were plantigrade
• ,
• Nearly all reptiles (including but excluding (including most ) which are digitigrade or semi-digitigrade) are plantigrade
• Amphibians
• All amphibians are plantigrade

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Evolution 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.

In humans and other great apes, another possible advantage of a plantigrade foot is that it may enhance fighting performance by providing a more powerful stance for striking and grappling.

Plantigrade foot occurs normally in humans in static postures of standing and sitting. It should also occur normally in gait (walking). Hypertonia, spasticity, clonus, limited range of motion, abnormal flexion neural pattern, and a plantar flexor (calf) muscle contracture, as well as some forms of footwear such as high heeled shoes may contribute to an individual only standing and/or walking on their toes. It would be evident by the observable heel rise.

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