Tarsus

The tarsal bones are quite different from the carpal bones of the hand. They are designed to physiologically distribute the body's weight to the plantar surface of the foot, absorb the shockwaves, and, finally, precisely measure the projection of the body mass center.

Bones of the foot. The plantar view — *Ossa tarsi in situ*. The dorsal view.

Talus

In contrast with the carpal bones, in the foot, there is only one bone directly articulating with the proximal extremity skeleton – only the talus articulates with the tibia & fibulatibia & fibula. The body weight pressure is distributed between the dorsally displaced tuber calcanei and – through the chain of other tarsal bones – to the metatarsal bones.

The topography of the talus — The right talus bone *in situ & ex situ*. The top posterior view.
Click the image to see the bones directly contacting the talus – the concave surface of the navicular bone and three separate articulatory facets on the calcaneus's top surface.
The list of terms:
*Trochlea tali*
*Facies malleolaris medialis* – Medial malleolar surface
*Facies superior* – Superior surface
*Facies malleolaris lateralis* – Lateral malleolar surface
*Processus posterior tali* – Posterior process of talus
*Tuberculum mediale* – Medial tubercle
*Tuberculum laterale* – Lateral tubercle
*Sulcus tendinis m. flexoris hallucis longi* – Groove for the tendon of flexor hallucis longus muscle
*Os naviculare* – Navicular bone
*Calcaneus* – Heel bone
*Facies articularis talaris anterior* – Anterior facet for the talus
*Facies articularis talaris media* – Middle facet for the talus
*Facies articularis talaris posterior* – Posterior facet for the talus
*Sustentaculum tali*

The bottom view of the ankle bone — The right talus *in situ & ex situ*. The bottom view.
Please note that in contrast with the three separate articular facets on the calcaneus's top surface, the talus's congruent anterior and middle articular facets are usually fused with the head of the talus.
The list of terms:
*Caput tali* – Head of talus
*Facies articular navicularis* – Navicular articular surface
*Facies articulars calcanea anterior* – Anterior calcanean facet
*Facies articularis calcanea media* – Middle calcanean facet
*Facies articularis calcanea posterior* – Posterior calcanean facet
*Sulcus tali* – Sulcus of talus
*Sulcus tendinis musculi flexoris hallucis longi* – Groove for the tendon of m. flexor hallucis longus

Calcaneus

The medial view of the heel bone in situ et ex situ — The medial aspect of the righ heel bone *in situ & ex situ*.
The most prominent feature seen from the medial aspect of the heel bone is the sustentaculum tali. The word sustentaculum derives from the Latin and means support or sustenance. That term seems to be appropriate: the pressure transmitted through the talus (i.e., the weight of the whole body) is, to a great extent, directed toward that medial prolongation of the heel bone.
The list of terms:
*Tuber calcanei*
*Processus lateralis tuberis calcanei* – Lateral process of calcaneus
*Processus medialis tuberis calcanei* – Medial process of calcaneus
*Tuberculum calcanei* – Calcaneal tubercle
*Sustentaculum tali*
*Sulcus tendinis m. flexoris hallucis longi* – Groove for the tendon of m. flexor hallucis longus
*Facies articularis cuboidea* – Cuboid articular surface
*Facies articularis talaris anterior* – Anterior facet for the talus
*Facies articularis talaris media* – Middle facet for the talus
*Facies articularis talaris posterior* – Posterior facet for the talus

The top view of the heel bone in situ et ex situ — The top view of the right heel bone *in situ & ex situ*.
You will find the three distinct articulatory facets for talus bone on the superior surface of the calcaneus. The lateral facet localizes on top of the *sustentaculum*.
The list of terms:
*Sustentaculum tali*
*Sulcus tendinis m. flexoris hallucis longi* – Groove for the tendon of m. flexor hallucis longus
*Facies articularis cuboidea* – Cuboid articular surface
*Facies articularis talaris anterior* – Anterior facet for the talus
*Facies articularis talaris media* – Middle facet for the talus
*Facies articularis talaris posterior* – Posterior facet for the talus
*Sulcus calcanei*

The lateral view to the foot bones — The image above demonstrates the lateral aspect of the foot, showing a slight impression on the heel bone's lateral surface caused by the pressure from the tendon of the long peroneal muscle.
The list of terms:
*Sinus tarsi*
*Trochlea peronealis* – Peroneal trochlea
*Sulcus tendinis m. peronei longi* – Groove for the tendon of the peroneus longus muscle

Os Naviculare & Os Cuboideum

The foot bones split — The dorsal aspect of the foot skeleton.
Click an image to see the foot's functional split: the navicular bone transmit the pressure force from the talus to the cuneiform bones and further – to the 1^st, 2^nd, and 3^rd metatarsal bone. In contrast, the cuboid bone transmits the calcaneus's pressure force directly to the 4^th and 5^th metatarsal bones.

Os Cuneiforme Mediale, Intermedium & Laterale

The topography of the cuneiform bones. The frontal view — Cuneiform bones *in situ*. The frontal aspect.
Note the wedge-like shape of these bones (from Latin *cuneus* – wedge).
The list of terms:
*Os cuboideum* – Cuboid bone
*Os cuneiforme mediale* – Medial cuneiform
*Os cuneiforme intermedium* – Intermeiate cuneiform
*Os cuneiforme laterale* – Lateral cuneiform

The topography of the third metacarpal bone — Cuneiform bones *in situ*. The posterior aspect.

The list of terms:
*Os cuneiforme mediale* – Medial cuneiform
*Os cuneiforme intermedium* – Intermeiate cuneiform
*Os cuneiforme laterale* – Lateral cuneiform

360° rotation of the bones of the foot.

First published: 15/Dec/2020
Last update: 20/Dec/2020