The ankle joint is made up of two joints: the true ankle joint, which moves the foot up and down, and the subtalar joint, which moves the foot from side to side. The ankle mortise is the "hinge" that connects the ends of the tibia and fibula to the talus.
Significance
The true ankle joint is made up of the tibia, which is on the inside, the fibula on the outside and the talus, which is the underneath part of the joint. The subtalar joint consists of the talus on the top and the calcaneus on the bottom. The ankle mortise is significant because it joins the tibia and fibula to the talus.
Features
The ankle mortise features three articulations or "movable joints between bones." They are the fibular latural malleolar, on one side, and the tibial medial malleolar on the other side. The tibial dome is above the mortise.
Function
Two tough ligaments support the mortise. The cylindrical shape of the ankle bone rolls within the mortise.
Benefits
The mortise is beneficial to the range of motion of the ankle. The ankle goes up and down in the mortise, forming a pivot.
Read more: Definition of Ankle Mortise | eHow.com
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