Calcaneus

Calcaneus
The calcaneus forms the bony part of the heel. It forms a joint with the talus bone, the subtalar joint.
Bones of the foot, with the calcaneus shown in red
Details
Latin	Calcaneus, Calcaneum, Os calcis
Identifiers
MeSH	A02.835.232.043.300.710.300
TA
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	24496
Anatomical terms of bone [[[d:|edit on Wikidata]]]

In humans, the calcaneus (/kælˈkeɪniːəs/; from the Latin calcaneus or calcaneum, meaning heel) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock.

Structure

In humans, the calcaneus is the largest of the tarsal bones and the largest bone of the foot. The talus, calcaneus, and navicular are considered the proximal row of tarsal bones. In the calcaneus, several important structures can be distinguished:

The half of the bone closest to the heel is the tuber calcanei. On its lower edge on either side are its lateral and medial processes (serving as the origins of the abductor hallucis and abductor digit minimi). The calcaneal (Achilles) tendon is inserted into a roughened area on its superior side, the cuboid bone articulates with its anterior side, and on its superior side are three articular surfaces for the articulation with the talus bone. Between these superior articulations and the equivalents on the talus is the tarsal sinus (a canal occupied by the interosseous talocalcaneal ligament). On the medial side of the bone, below the middle talar facet, is the sustentaculum tali (which serves for the attachment of several other ligaments). On the lateral side is commonly a tubercle called the peroneal trochlea, under which is a groove for the tendon of the peroneus longus.

The calcaneus is part of two joints: the proximal intertarsal joint and the talocalcaneal joint. The point of the calcaneus is covered by the calcanean bursa.

Development

In the calcaneus, an ossification center is developed during the 4th–7th week of fetal development.

Function

Three muscles attach to the calcaneus: the gastrocnemius, soleus, and plantaris. These muscles are part of the posterior compartment of the leg and aid in walking, running and jumping. Their specific functions include plantarflexion of the foot, flexion of the knee, and steadying the leg on the ankle during standing.

File:Gray268.png Muscle attachments (seen from above)

File:Gray269.png Muscle attachments (seen from below)

Muscle	Direction	Attachment
Gastrocnemius	Insertion	Tuber calcanei through the achilles tendon
Soleus	Insertion	Tuber calcanei through the achilles tendon
Plantaris	Insertion	Tuber calcanei either directly or through the achilles tendon
Extensor digitorum brevis	Origin	Dorsal side of calcaneus
Abductor hallucis	Origin	Medial process of calcaneus
Extensor hallucis brevis	Origin	Dorsal side of calcaneus
Abductor digiti minimi	Origin	Tuber calcanei
Flexor digitorum brevis	Origin	Tuber calcanei
Quadratus plantae	Origin	Lateral and medial processes of calcaneus

Clinical significance

Calcaneus fracture X-ray

See also: Calcaneal fracture

Normally the tibia sits vertically above the calcaneus (pes rectus). If the calcaneal axis between these two bones is turned medially the foot is in an everted position (pes valgus), and if it is turned laterally the foot is in an inverted position (pes varus).

• Calcaneal fracture, also known as Lover's fracture and Don Juan fracture

See also

This article uses anatomical terminology; for an overview, see Anatomical terminology.

• Calcar
• Bohler's angle
• Sanders classification

Additional images

• 

  Left calcaneus. Animation.

• Ospied-de.svg

  Bones of foot

• 

  3D rendering of a left calcaneus derived from CT scan data. The calcaneus is white, and the other bones of the foot and ankle are clear to illustrate the position and relationship of the calcaneus to the other tarsal bones.

External links

• lljoints at The Anatomy Lesson by Wesley Norman (Georgetown University) (posterioranklejoint)
• 3D printable calcaneus model, free download in STL format (Embodi3D.com)