In each human foot, there are five parallel
metatarsal bones that form the front of the
instep. They spread toward the front of the foot to form the
ball of the foot.
Each metatarsal has three parts:
- base: the proximal end of the metatarsal; it articulates with the distal row of tarsal bones.
- body: also known as the diaphysis; it is the slender shaft of the metatarsal.
- head: the rounded distal end of the metatarsal
between the tarsus and the phalanges.
Most of a person's weight is balanced on the
first and
fifth metatarsals. The first metatarsal (ball of the
big toe) is short and thick, so it is able to withstand a lot of
abuse. There are also two
sesamoid bones beneath it that help. The fifth is not as strong, and is four times more likely to be
injured if it belongs to a
woman (gotta love those high heels).