LOCATION

It is present just below the talus bone (which is present below the lower end of tibia and fibula bones) thus contributing in making the hind part of the foot.

GENERAL BONEY FEATURES OF CALCANEUS BONE

This bone has six surfaces:

• The anterior surface is the smallest surface of all. It has an articular surface for making a joint with the cuboid bone.

• The posterior surface is divided into three areas

• The dorsal (superior) surface makes joint with the talus bone.

• The plantar surface  is rough. It has three tubercles present on it.

• The lateral surface is rough and is almost flat. This has a small elevation present anteriorly, called peroneal trochlea.

• The medial surface is concave. This surface has a shelf like projection, called the sustentaculum tali.

ATTACHMENTS

Muscles inserted on this bone are:

• Plantaris (on posterior surface)

• Tendocalcaneal which is a tendon not muscle (also on posterior surface)

Muscles originating from this bone are:

• Extensor digitorum brevis (from dorsal surface)

• Abductor hallucis (from plantar surface)

• Abductor digiti minimi (from lateral tubercle)

SOME CLINICAL ASPECTS

Sometimes, a calcaneal spur (it is a small bony projection that is formed from calcaneus) is developed which is very painful.

The calcaneus fractures occur when someone falls from a height.