The subtalar joint is located just below the ankle joint between the talus and the calcaneus (heel bone). The main job of the subtalar joint is to allow for side-to-side movement of the foot and ankle. This movement aids in walking, especially on uneven surfaces.
When there is a problem in the subtalar joint, the location of pain is described as being deep. The exact location may be hard to describe. Pain may be felt in the soft spot on the outside of the ankle or in a horseshoe distribution behind and below the ankle.