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:

  1. base: the proximal end of the metatarsal; it articulates with the distal row of tarsal bones.
  2. body: also known as the diaphysis; it is the slender shaft of the metatarsal.
  3. 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).

Log in or register to write something here or to contact authors.