Subtalar joint

Image:Subtalar Joint.PNG Image:Gray354.png

For a review of anatomical terms, see Anatomical positionand Anatomical terms of location.

In human anatomy, the subtalar joint, also known as the talocalcaneal joint, is one of two jointsin the ankle. It occurs at the meeting point of the talusand the calcaneus, two bonesin the ankle. The joint allows inversion (a combination of adduction and plantar flexion) and eversion (a combination of abduction and dorsiflexion).

The talus is oriented slightly obliquely on the anterior surface of the calcaneus. There are two points of articulation between the two bones: one anteriorly and one posteriorly. At the anterior talocalcaneal articulation, a convexarea of the talus fits on a concavesurface of the calcaneus. The posterior talocalcaneal articulation is formed by a concave surface of the talus and a convex surface of the calcaneus.

The main ligamentof the joint is the interosseous Talocalcaneal ligament, a thick, strong band of two partially joined fibers that bind the talus and calcaneus. It runs through the sinus tarsi, a canal between the articulations of the two bones.

There are four additional ligaments that form weaker connections between the talus and calcaneus. The anterior talocalcaneal ligament (or anterior interosseous ligament) attaches at the neck of the talus on the front and lateral surfaces to the superior calcaneus. The short band of the posterior talocalcaneal ligament extends from the lateral tubercle of the talus to the upper medial calcaneus. The short, strong lateral talocalcaneal ligament connects from the lateral talus under the fibular facet to the lateral calcaneus, and runs parallel to the calcaneofibular ligament. The medial talocalcaneal ligament extends from the medial tubercle of the talus to the sustentaculum tali on the medial surface of the calcaneus.

A synovial membranelines the capsule of the joint, and the joint is wrapped in a capsule of short fibers that are continuous with the talocalconeonavicular and calcaneocuboid joints of the foot.

Sources

• Calais-Germain, Blandine. "Anatomy of Movement", Eastland Press, 1993. ISBN 0939616173
• Anatomy of the Human Body, Henry Gray, 1918

This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/Subtalar+joint Wikipedia article Subtalar joint.