Tarsus

Tarsus is a cluster of seven articulating bones in each foot situated between the lower end of tibia and fibula of the lower leg and the metatarsus. It is made up of the talus, calcaneus, navicular bone, cuboid bone, and three cuneiform bones. The tarsus forms the lower part of the ankle joint through its articulation with the ends of the tibia and fibula. It also forms the heel and instep of the foot.

Structure[edit]

The tarsus is made up of seven bones, which can be grouped into the proximal and distal groups. The proximal group is formed by the talus and calcaneus, while the distal group is formed by the remaining five bones, including the cuboid, navicular, and three cuneiform bones.

Proximal Group[edit]

The talus or ankle bone is the second largest bone in the foot. It carries the weight of the body from the tibia above to the calcaneus below. The calcaneus or heel bone is the largest bone in the foot. It is located beneath the talus and forms the bony prominence of the heel.

Distal Group[edit]

The navicular is boat-shaped and located on the medial side of the foot, in front of the talus and behind the three cuneiform bones. The cuboid is on the lateral side of the foot in front of the calcaneus and behind the fourth and fifth metatarsal bones. The three cuneiforms are arranged in a row on the medial side of the foot, in front of the navicular bone and behind the first, second, and third metatarsal bones.

Function[edit]

The tarsus provides a strong and flexible framework for the foot, allowing it to support the weight of the body, absorb shock, and adapt to uneven surfaces. The talus and calcaneus play a crucial role in weight-bearing and propulsion, while the other bones contribute to the foot's arches and act as a lever for muscles.

Clinical Significance[edit]

Injuries to the tarsus, such as fractures and dislocations, can result in significant disability. Conditions such as flat feet and high arches can also affect the tarsus and lead to pain and other problems.