Overview of the calcaneus

Hello everyone! This is Matt from Kenhub, and in this tutorial, we will be looking at the calcaneus.

The calcaneus, also known as the heel bone, is located in the posterior foot inferior to the talus and, superiorly, we find the tibia and fibula. It is the largest bone of the foot and projects posteriorly to form the heel. The calcaneus plays an important role in weightbearing and stability. It also acts as a short lever for the soleus muscle and the gastrocnemius muscle. These muscles both insert on the posterior surface of the calcaneus via the calcaneal tendon in the highlighted area on the image to the right. The calcaneal tendon is commonly referred to as the Achilles tendon.

The calcaneus is an irregular, cuboidal-shaped bone. As we have already seen, its posterior aspect projects out forming the heel and takes on a concavo-convex shape. The concave side indicated here is the area of support for the fibroadipose tissue known as Kager's fat pad which provide support for the Achilles tendon among other stabilizing functions. There is also a rough depression on the superior surface of the calcaneus highlighted known as the calcaneal sulcus which coordinates with the talus to form the sinus tarsi.

Another notable feature of the calcaneus lying on its lateral aspect is a projection known as the peroneal tubercle indicated here to which the tendons of the fibularis brevis and fibularis longus muscles attach.

The calcaneus articulates with two bones – the talus and the cuboid bone. It possesses three articular facets for the talus. The posterior talar articular surface of calcaneus is the largest of the three articular surfaces or facets. Next is the middle talar articular surface of calcaneus situated anteromedially to the posterior talar articular surface. And, finally, the third articular surface – the anterior talar articular surface of calcaneus – which is the smallest of the three talar articular surfaces.

There was one articular surface on the calcaneus for the cuboid bone called the cuboidal articular surface of calcaneus shown here in green.

Being the largest bone in the foot, the calcaneus provides ample surface area for many attachments including the following muscles – the gastrocnemius muscle and the soleus muscle, the extensor hallucis brevis muscle, the extensor digitorum brevis muscle, the flexor digitorum brevis muscle, the abductor hallucis muscle, the abductor digiti minimi muscle, the quadratus plantae muscle.