Metatarsals
The five metatarsals are the key structures that connect the distal row of ankle bones to the toe bones on the body.
The metatarsals are numbered sequentially from the first to the fifth metatarsal, starting from the medial side, according to their anatomical position. Each of these bones has a unique characteristic: the first is the shortest and thickest, specialising in weight-bearing, while the second is usually the longest and plays an important role in the formation of the foot's arch. In particular, the second and third tarsal bones are most strongly attached to the distal row of ankle bones, providing stability when walking. This anatomy is optimised to allow the strong propulsive forces generated during the push off phase of walking to pass effectively through this area of the forefoot.
Each tarsal bone is made up of three main structural parts. These are the base at the near end, the shaft in the middle, and the convex head at the far end.
The tarsometatarsal bases have small articular surfaces that delicately interlock with the neighbouring tarsal bases, contributing to the formation of the transverse arch of the foot.
When viewed in the longitudinal direction, the tarsal bones are subtly concave on the plantar side. This biomechanically optimised bow-shaped structure effectively distributes the stresses of weight bearing and provides anatomical space for the muscles and tendons of the foot to work efficiently.
At the base of the first tarsal head, there are two specialised articular surfaces that intricately interlock with the two sesamoid bones, which are located alongside the tendons of the flexor hallucis brevis. In addition, the base of the fifth tarsal bone has a styloid process, a characteristic bump to which the fibularis brevis muscle attaches strongly.
Phalanges
Like the human hand, the foot has a total of 14 toe bones (phalanges), which are important structures located on the furthest side of the foot. Each of the four toes on the lateral side is made up of three toe bones: the proximal, middle, and distal toe bones.
The first toe, commonly referred to as the great toe (hallux), has only two toe bones, unlike the other toes: the proximal and distal toe bones. All toe bones have three main structural features in common: a concave base at the proximal end, a body in the middle, and a rounded head at the distal end.