The one-leg stand test is a standard field sobriety test used by law enforcement to determine whether an individual driving a motor vehicle is under the influence of alcohol or drugs. In the one-leg stand test, the individual suspected of driving under the influence (DUI) is asked to stand with one foot approximately six inches off the ground with the toe pointed while maintaining perfect balance. They are then asked to count for thirty seconds. Additionally, suspects must keep looking down at their foot and keep their arms at their sides. Law enforcement officers at the scene look for signs of impairment while the suspect performs the test.
Field sobriety tests are used by law enforcers for an on-the-spot determination of whether an individual is driving while intoxicated (DUI) or driving while impaired (DWI). The one-leg stand test is one such field sobriety test, and it was developed by the National Highway Traffic and Safety Administration (NHTSA). Though the test is fairly simple and takes only 30 seconds, the officer administering the test must ensure that the individual suspected of DUI properly understands the procedure by both explaining and demonstrating the test.