An unnatural twisting motion can happen when the foot is planted awkwardly, when the ground is uneven, or when an unusual amount of force is applied to the joint. Such injuries happen during athletic events, while running or walking, or even doing something as simple as getting out of bed. Sprain occur when the ligaments are stretched more then normal. These results in a partial tear or complete tear of the ligament. This ligament damage results in the development of abnormal motion at the joint due to the loss of stability.