The subtalar joint, also referred to as the talocalcaneal joint, is one of the joints located in the foot. It is located where the talus and the calcaneus meet. The subtalar joint is responsible for allowing certain types of movement of the foot, particularly those movements known as eversion and inversion.
The talus is a bone found in the foot, helping to form the bottom portion of the ankle. The talus is joined to the calcaneus, better known as the heel bone, by the subtalar joint. This joint is generally classified as a type of synovial joint, although it is sometimes referred to as an uniaxial hinge joint.
Inversion is one of the types of movement allowed by the subtalar joint. Inversion occurs when the sole of the foot moves in the direction of the median plane, the anatomical line used to divide the body into right and left sides. An example of foot inversion is the direction of movement when the ankle is twisted inward.
Eversion, another type of movement made possible by the subtalar joint, is basically the opposite of inversion. This type of movement occurs when the sole of the foot is moved in a direction opposite of the median plane. Along with inversion, this is the only type of movement made possible by the subtalar joint.
The inversion and eversion movements allowed by the subtalar joint are commonly associated with foot injuries. Such injuries are common in sports and high-intensity athletic training, especially when athletes fail to warm up the joint before engaging in activity. Very rarely, dislocation of the joint can occur, but this is most commonly associated with high-impact auto accidents and falls from great height.
Due to the location of the subtalar joint and the amount of use it gets on a constant basis, arthritis affecting this area is a common ailment. Arthritis occurs when a joint becomes inflamed or swollen. This condition causes moderate to severe pain and can severely limit the ability to function at a normal level. Arthritis itself has no known cure. Therefore, treatment is directed at alleviating individual symptoms with exercise, anti-inflammatory and over-the-counter pain medications, and prescription medications.
In extreme cases of arthritis, the joint may require surgery. This often becomes necessary when the cartilage protecting the joint breaks down. In the case of the subtalar joint, a foot fracture could cause this type of damage, making surgery the most viable option for repair. In order to prevent joint damage, any unusual pain or discomfort should be reported to a medical professional.