Sprained ankles are common injuries. Approximately 25,000 people experience sprained ankles each day. A high ankle sprain injures ligaments connecting the two bones of the lower leg, the tibia and the fibula, at the ankle joint. A medial ankle sprain injures the inside ligaments or collectively the deltoid ligament, which attaches the medial malleolus to multiple tarsal bones. A low ankle sprain involves the ligaments supporting the subtalar joint, which enables the foot to turn to the inside and outside. Symptoms include pain, swelling, bruising, and joint instability.