Navicular
The navicular bone is so named because of its distinctive ship-shaped morphological feature. The proximal portion of the navicular bone has a concave articular surface that articulates with the head of the navicular bone in the talonavicular joint, forming a stable joint.
The distal part of the navicular bone has strategically placed relatively flat articular facets that articulate harmoniously with the three cuneiforms. The medial surface of the navicular bone is characterised by a distinctly raised navicular tuberosity, which can be easily palpated in adults at a distance of approximately 2.5 cm inferiorly and distally (anteriorly) from the tip of the medial radius.
This rough surface of the plantar bone serves as a key anatomical structure to which the tibialis posterior, an important muscle of the foot, attaches firmly from the distal side.
Medial, Intermediate, Lateral Cuneiform
The cuneiform owes its Latin name to its characteristic wedge shape. These three wedges act as effective spacers between the three inner bases of the metatarsals and the navicular bone, providing structural stability to the foot.
They also play a key role in the formation of the transverse arch of the foot, contributing decisively to the creation of a stable transverse convex structure on the dorsal surface of the midfoot.
Cuboid
As its name suggests, the cuboid is an ankle bone with a shape similar to a cube, with six characteristic faces.
Three of these faces form elaborate articular connections with the surrounding ankle bones, contributing to the structural stability of the foot. The most distal face articulates with the base of the fourth and fifth tarsal bones to control the movement of the lateral part of the foot. Due to these anatomical characteristics, the cuboid is functionally homologous to the hamate bone found in the wrist.
The cuboid's ventral surface, which is gently curved throughout, forms a stable joint with the heel bone. There are two important articular facets on this side: the characteristic egg-shaped articular facet that articulates with the lateral sphenoid, and a smaller articular facet that articulates with the palmar bone. The bottom surface of the cuboid bone has a distinctive deep transverse groove called the cuboidal furrow, which provides a safe passage for the tendon of the fibularis longus to run through.