Human Anatomy - Kotsan I. Ya. 2009

Skeleton of the Lower Limb
Bones of the Toes

The BONES OF THE toes — the Phalanges — are short tubular bones. Each toe, with the exception of the great toe, consists of three phalanges: the proximal phalanx (phalanx proximalis), the middle phalanx (phalanx media), and the distal phalanx (phalanx distalis). The great (first) toe has two phalanges: a proximal and a distal one. Often, the two phalanges of the fifth toe (the little toe) fuse together, resulting in just two phalanges as well. Each phalanx comprises a base (basis phalangis), a body (corpus phalangis), and a HEAD (caput phalangis). Instead of a head, the distal phalanges feature a terminal expansion known as the tuberosity of the distal phalanx (tuberositas phalangis distalis). The base of each proximal phalanx has a facet that articulates with the head of the corresponding metatarsal bone. The bases of the middle and distal phalanges feature two flat facets separated by a ridge for articulation with the heads of the more proximally positioned phalanges.

Similar to the hand, the FOOT contains sesamoid bones (ossa sesamoidea). These are significantly more pronounced in the foot and are located in the region where the first and fifth metatarsals join the proximal phalanges. The sesamoid bones enhance the transverse arch of the metatarsus in its anterior part. There is also a sesamoid bone embedded in the tendon of the fibularis (peroneus) longus Muscle, situated on the plantar surface of the cuboid bone. Additionally, sesamoid bones are occasionally found between the proximal and distal phalanges of the great toe.