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.
  
  

Warning

• Ankle injuries happen when the foot rolls onto the outside of the ankle. Ankles are prone to this type of injury because of the small size of the joint in comparison to the leg and foot. You should pay attention to the surface of which you are walking, running or jumping.