You just saw your favorite athlete take the field (or floor) wearing an ankle brace. "Oh no," you think. He or she must have had an injury! Maybe not. Many athletes wear ankle braces to prevent an injury. Studies show that ankle bracing can reduce the risk of an ankle sprain.

This study tried to find out which ankle brace is the best one to use when jumping and landing on an object. Most often, players land on another athlete's foot or a rock on the field. The ankle twists inward, and an injury occurs. This type of ankle sprain is called ankle inversion.

This study mimicked conditions during an ankle inversion injury. Each subject jumped up and landed on one foot with a force equal to twice his body weight. A special sole on the shoe forced the foot into an inverted position. The 14 subjects landed on a special plate that measured the force of the impact. A microcomputer collected the data.

Three different braces were tested: the Swede-O, Aircast, and Bledsoe. The Swede-O is made of a soft nylon with laces up the front and elastic in the back. The Aircast is a semi-rigid brace with air-filled padding on either side. The Bledsoe is semi-rigid with metal stays on either side. It has a hinge joint at the ankle to allow foot motion up and down.

How well did they work? Which one was best? All three were able to protect the ankle from turning in after jumping and landing on one leg. The Aircast and Bledsoe held the ankle more stable than the Swede-O. Which one did the athletes prefer? The Swede-O was ranked the most comfortable. Players had more confidence in the Aircast and Bledsoe. Soccer players reported that the Bledsoe didn't allow enough foot motion to play normally.

The authors conclude that a semi-rigid ankle brace works best in preventing ankle inversion. Ground reaction forces in basketball rebounding can reach three to 14 times the athlete's body weight. Back somersaults in gymnastics and landing from a block in volleyball have similar forces. Athletes may want to use ankle bracing to prevent ankle injuries during sports with this kind of impact.