An inversion injury is the most common cause of an ankle sprain and occurs when the ankle rolls outward and the foot turns inward. It results in stretching and tearing of the ligaments on the outside of the ankle.

Less commonly, the ankle rolls inward and the foot outward in an eversion injury, damaging the ligaments at the inside of the ankle.

The high ankle sprain is the least common. It can happen when the foot is forced to rotate toward the outside (away from the other foot), or when the foot is planted so it can't move and the leg is rotated toward the inside.