Tarsal Bones

What Do You Know About the Tarsal Bones and Their Location

The foot contains a cluster of 7 irregularly shaped bones known as tarsal bones, also referred to as the tarsus. These bones are situated in the lower parts of the tibia and fibula of each foot, forming the midfoot and hindfoot.

How Many Bones Make Up the Tarsus

Each foot consists of 7 tarsal bones, specifically: ankle bone (talus), heel bone (calcaneus), boat-shaped bone (navicular), cuboidal bone (cuboid), and three wedge-shaped cuneiform bones (lateral, intermediate, and medial cuneiforms).

Role

These bones offer mechanical support to the soft tissues of the foot, aiding in bearing the body’s weight. They contribute to the formation of a longitudinal arch, working in conjunction with other foot bones to create a sturdy weight-bearing platform during standing and movement.

Anatomy and Composition

As mentioned earlier, some tarsal bones form the midfoot, while others build the hindfoot. These foot bones are arranged in three rows: proximal, intermediate, and distal.

Now, let’s discuss each of the 7 bones:

Bones in the Hindfoot (Proximal Tarsal Bones)

The hindfoot is composed of two proximal tarsal bones, namely: ankle bone (talus) and heel bone (calcaneus). These bones form the bony framework surrounding the ankle and heel.

1. Talus (ankle bone): This is the most superior bone and forms the ankle joint by articulating with the tibia and fibula.
2. Calcaneus (heel bone): It is the largest tarsal bone located beneath the talus, constituting the heel.

An important structure in this part of the foot is the tarsal tunnel, a passageway between the foot and the posterior part of the leg, formed by the talus, calcaneus, and tibia. It allows the passage of multiple tendons, nerves, and blood vessels.

Bones in the Midfoot (Intermediate and Distal Tarsal Bones)

In the midfoot, the tarsal bones are divided into two regions: intermediate and distal. The intermediate row comprises the navicular bone, while the distal region consists of the cuboid and the three cuneiform bones.

1. Navicular: This boat-shaped bone articulates with all other tarsals, except for the calcaneus.
2. Cuboid: As the name implies, it has a cuboidal shape and is positioned anterior to the calcaneus, being the most lateral bone in the distal row, located at the side of the little toe.
3. Lateral Cuneiform: A wedge-shaped bone, situated at the most lateral position among the three cuneiform bones, on the side of the big toe.
4. Intermediate Cuneiform: Another cuneiform bone with a similar shape, located between the lateral and medial cuneiform bones.
5. Medial Cuneiform: This wedge-shaped cuneiform bone lies anterior to the navicular bone.

Mnemonic for Remembering Tarsal Bones

The following acronyms can be used to easily recall the names of all 7 tarsal bones.

• Tiger Cub Needs MILC.
• The Cab in New Mexico Is Land Cruiser.

Breaking down the mnemonic:

T: Talus

C: Calcaneus

N: Navicular

M: Medial cuneiform

I:  Intermediate cuneiform

L: Lateral cuneiform

C: Cuboid

Joints and Connections in the Tarsal Region

• Ankle joint: Formed between the talus, tibia, and fibula
• Subtalar joint: Located between the talus and calcaneus
• Talonavicular joint: Present between the talus and navicular
•  Subtalar or talocalcaneal joint: Formed between the calcaneus and talus
• Calcaneocuboid joint: Located between the calcaneus and cuboid

Carpal Bones vs. Tarsal Bones

References

1. Bones of the Foot: Tarsals, Metatarsals and Phalanges – Teachmeanatomy.info
2. Tarsals, Metatarsals, and Phalanges (The Foot) – Med.libretexts.org
3. Tarsal bones – Radiopaedia.org
4. Tarsals | Tarsal Bones Anatomy – Getbodysmart.com
5. Tarsal Bone – Sciencedirect.com