Overview

The term "tarsals" refers to a group of bones located in the posterior part of the human foot, often described in everyday language as the ankle bones. In each foot there are seven tarsal bones that form the connection between the lower leg and the forefoot. They provide a stable platform for weight-bearing and contribute to the complex motions required for standing, walking and running.

Anatomy and parts

The tarsal bones are arranged into a proximal row and a distal row and include several distinct elements:

  • Talus — transmits weight from the tibia and forms the main ankle articulation.
  • Calcaneus — the heel bone and primary attachment for the Achilles tendon.
  • Navicular — sits medially and helps form the arch.
  • Cuboid — on the lateral side, articulates with the fourth and fifth metatarsals.
  • Three cuneiforms — medial, intermediate and lateral, located between the navicular and the first three metatarsals.

Development and evolution

Tarsal bones form by endochondral ossification during childhood and continue to mature into adolescence. Evolutionarily, tarsals are homologous structures across tetrapods and have adapted to different modes of locomotion; in humans they are specialized for bipedal weight transfer and shock absorption.

Function and biomechanics

Grouped with ligaments and tendons, the tarsals create stable arches and flexible joints. The talocrural (ankle) and subtalar joints allow dorsiflexion/plantarflexion and inversion/eversion, respectively. These motions let the foot adapt to uneven ground while transmitting forces efficiently through the lower limb.

Clinical significance and common conditions

Tarsal fractures, arthritis, tarsal coalition (abnormal fusion) and problems affecting the surrounding soft tissues can impair mobility and cause pain. The calcaneus is often involved in heel pain syndromes; the talus is vulnerable to injury that may threaten joint function. Imaging, conservative care and, when needed, surgery address many tarsal disorders.

Notable distinctions

Though sometimes compared to the wrist's carpal bones, tarsals are generally larger and bear more weight. They articulate with metatarsals distally and the leg bones proximally, forming a transitional region critical to posture and gait.