Greg Knowland, age 11, of Hattiesburg, Miss., for his question:'

WHAT HAPPENS WITH A SPRAIN?

A sprain occurs when ligaments covering a joint are torn or twisted.

A ligament is fibrous tissue that holds organs of the body in place and fastens bones together. Ligaments are grouped together in cords, bands or sheets. They are as strong as rope.

A sprained ankle is a partial tearing of the talofibular ligament that binds the bones of the lower leg to the bones of the foot.

Ligaments heal slowly. They may never heal if they are completely torn apart.

Doctors bind sprained body parts with tape or elastic bandage, or enclose them in plaster casts. This takes pressure off the joint, rests the joint, relieves pain and helps ligaments to heal.

Most sprains result from a sudden wrench that stretches or tears the tissues of the ligaments. Sprains of the ankle and wrist are most common, but a person may sprain any joint.

A sprain is usually extremely painful. For some, a doctor may apply cold compresses first and then warm compresses.