A simple test - basically standing on one leg with eyes closed - can help identify whether or not an athlete is at risk of spraining an ankle, a new study shows.

As many as one in five athletic injuries are due to ankle sprains, and disability from the injury can persist for up to six months, Drs. Thomas H. Trojian of the University of Connecticut Health Center in Hartford and D.B. McKeag of the Indiana University School of Medicine in Indianapolis note in the British Journal of Sports Medicine.

Ankle sprains also reduce a person’s stability, boosting the risk of a repeat injury, they add.

A test known as stabilometry can identify whether or not a person is at increased risk of ankle sprain, Trojian and McKeag explain, but it requires special equipment that is too costly for most high schools.

The single leg balance test, in which a person stands on one foot with the other leg bent and then closes their eyes for ten seconds, could provide a more readily available alternative. If a person can’t keep his or her balance for the full ten seconds or reports feeling a sense of imbalance during the test, he or she may be at increased risk of ankle sprain.

To investigate whether the single leg balance test could predict ankle sprain risk, the researchers performed the test in 230 high school varsity and intercollegiate athletes. The study participants underwent the test before the beginning of the autumn sports season.

During the season, 28 ankle sprains occurred. People with a positive standing leg balance test - meaning it revealed balance problems - were two-and-a-half times more likely to suffer ankle sprains. Those who had a positive test and did not tape their ankles were nearly nine times as likely to sprain their ankles.

The researchers also found athletes who reported having sprained their ankles in the past two years were more likely to have a positive standing leg balance test, but were not more likely to sprain their ankles during the current season.

In a brief commentary accompanying the study, Dr. E. J. Swenson of the University of Rochester in New York notes that the single leg balance test, along with a history of past injuries and a detailed physical exam, “could help identify those individuals who would benefit from bracing/taping, muscle strengthening, and proprioceptive training.”

SOURCE: British Journal of Sports Medicine, July 2006.