The One Leg Stand Field Sobriety Test
Transcript of “The One Leg Stand Field Sobriety Test”
Author: Steven Oberman
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Originally Posted: June 2, 2011
Have you driven by a police officer watching someone standing on one leg on the side of the road? Then you’ve likely observed someone taking a standardized field sobriety test.
This is your host, Steve Oberman, and in this episode I will provide a summary of the standardized one leg stand test. As a certified DUI detection and standardized field sobriety test instructor, I assure you it takes days of classroom and laboratory setting training to thoroughly understand the intricacies of this standardized field sobriety test, so keep in mind that this is only an overview.
This podcast will be much more meaningful if you have first listened to my previous podcast entitled, “The History of Field Sobriety Tests.” So, if you haven’t already listened to that episode, I recommend you do so before continuing.
Now, allow me to describe to you the procedures and scoring of the one leg stand test.
The instructions for this test are given to the subject while the subject stands with his feet together, and arms down at his side until told to start. After that, the subject is told to stand on one leg, holding the other foot approximately six inches off the ground pointed forward so that it is approximately parallel to the ground. While standing, the subject is to count out loud (one thousand and one, one thousand and two, and so on). The subject is to keep his arms at his sides at all times and watch the raised foot. The officer is then supposed to demonstrate a portion of the test before asking the subject to begin.
During the actual performance of the test, the officer is to observe the subject from a safe distance, and remain as motionless as possible during the test so as not to interfere. The officer will take special note of four things, which are called “clues.” These clues include:
- Swaying while balancing;
- Using arms for balance;
- Hopping; and
- Putting the foot down too soon.
You see, this test is supposed to take approximately 30 seconds. Should the officer observe two or more of these four clues, the subject fails this test as the officer may classify the subject’s blood alcohol level as above the legal limit or too impaired to drive safely.
In its original research the National Highway Traffic Safety Administration determined this SFST accurately indicated that a subject’s blood alcohol level was above .10% approximately 65% of the time. This test was the least accurate of the battery of three tests which comprise the standardized field sobriety tests.
But subsequent government research in San Diego, CA reported an 83% accuracy level for the one leg stand test in determining that a subject’s blood alcohol level was above .08%. So it was no longer the least accurate – the walk and turn test took that honor in the San Diego testing.
However, as you may have guessed, I have concerns in the manner in which that study and others were conducted and the conclusions that were reached in those studies. If you try this test while sober, you will likely agree it is difficult to perform without failing. A lawyer experienced in contesting DUI cases can often demonstrate the one leg stand test was given in an inappropriate environment, that instructions were given incorrectly or that the results were interpreted incorrectly.
So, now you have learned more about the procedures and scoring of the one leg stand test, which is part of the National Highway Traffic Safety Administration standardized field sobriety test battery. This test is given by an officer so that a better foundation for an opinion of impairment or estimated blood alcohol content may be made before an arrest decision is reached. This is your host, Steve Oberman, inviting you to join us next time to learn more about the issues relating to the crime of Driving Under the Influence of an Intoxicant.
We hope you enjoyed listening to the DUI law podcast1 produced by the Oberman and Rice Law Firm. You may read about related legal matter on our websites at http://www.tndui.com and http://www.duiknoxville.com or visit our blog at http://www.tnduicenter.com. You may also speak to one of our lawyers by calling (865) 249-7200. Until next time, remember to drive safely.
Portions of this podcast were taken from Mr. Oberman’s text, DUI: The Crime and Consequences, Published by West/Thomson Reuters, 2011.See https://www.tndui.com/oberman-dui-textbooks#tndui