What does plantigrade mean?
Plantigrade describes a form of locomotion in which an animal walks or stands on the entire sole of the foot, including the heel. Humans are plantigrade, as are bears and several other mammals. The term can also function as a noun for an animal with this kind of foot movement. It is especially useful in zoology, anatomy, and evolutionary biology because it distinguishes one basic foot posture from digitigrade locomotion, in which the heel remains raised and the animal moves on its toes, and from unguligrade locomotion, typically associated with animals supported on hooflike nails. The word comes from Latin planta, meaning the sole of the foot, and gradus, meaning a step. Although plantigrade is accurate and recognized across British and American English, it is primarily specialist vocabulary rather than a common everyday expression. The related adjective plantigradous is also encountered, though it is less frequent.
Walking or standing on the entire sole of the foot, with the heel in contact with the ground.
"The zoologist noted the animal's distinctly plantigrade posture."
Chiefly used in zoology, anatomy, and evolutionary biology.
An animal that walks or stands on the entire sole of the foot, including the heel.
"The bear is a plantigrade despite the common impression that large animals usually move on their toes."
Less common than the adjective; usually encountered in specialist or comparative-anatomical writing.
The plural is rarely needed because the noun is uncommon and often replaced by a broader term such as mammal.
"Humans and bears are examples of plantigrades."
Plantigrade puts the heel back on the ground: it is the formal name for the way humans and bears walk.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does plantigrade come from?
Plantigrade was formed in the early 19th century from Latin planta, “the sole of the foot,” and gradus, “a step.” The combining elements reflect the characteristic way of walking with the entire foot, including the heel, in contact with the ground. Its relatives include grade and gradient, both associated with gradus, and plantar and plant, which derive from the same Latin word for the sole of the foot.
Related word forms
How plantigrade is actually used
This is chiefly a technical zoological and anatomical term. It is uncommon in general speech, where simply walking with the heel on the ground may be clearer.
Easily confused with plantigrade
Plantigrade animals walk on the whole sole of the foot, whereas digitigrade animals walk on their toes with the heel raised.