For the unit of measurement, see foot (unit)
The foot has essentially the same anatomical structure and the same bones in different mammals, but is positioned and used for locomotion in different ways.
Animals with the unguligrade stance, including horses, cattle, and deer, walk only on the tips of the digits. In the horse, the anatomical structure corresponding to the foot is very elongated. In a famous mistake, the lexicographer Samuel Johnson defined the word pastern as "the knee of the horse." The pastern does look like a knee and it in roughly the location where you might expect a knee, but it faces backwards. Animals with the unguligrade stance are fast runners, depending on speed to escape predators, and their legs are long and relatively fragile.
- Wile, Dr. Jay L. Exploring Creation With Biology. Apologia Educational Ministries, Inc. 1998