DUI Training – One Leg Stand

[Ed. note – One leg stand testing is part 5 of a DUI Training series.  Other articles cover Horizontal Gaze Nystagmus, Walk and TurnVehicle in MotionPersonal Contact and specific safety concerns when conducting DUI investigations.]

The One-Leg-Stand (OLS) test is the final validated test in the NHTSA approved battery of three sobriety tests. Like the other two tests, the OLS is a divided attention test, meaning the subject being tested must divide their attention on several different instructions to successfully complete the test.

Operating a motor vehicle safely requires the driver to divide their attention (multi-task) on a continuous basis. You should familiarize yourself with with this concept as it helps a judge or jury understand that these tests are not meant to “fail” the tested subject, but are meant to gauge their ability to perform multiple tasks at the same time – something a sober driver does all the time.


Like the other two tests the subject should be instructed to stand with their feet together, heels and toes touching, and their arms down to their sides. The subject should be instructed to remain in that position while the rest of the instructions are being given. Once they have assumed that position ask them, “DO YOU UNDERSTAND?” Be sure to get a verbal acknowledgment that they understand before moving on to the other instructions.

One Leg Stand

Photo courtesy of Jeffrey Smith

Like the other tests the NHTSA Manual states that this test should be performed on a relatively dry, hard, and level surface. Use common sense here and go out of your way to ensure the safety of the tested person – this is your duty, but it also looks great in court.

Keep the subject in this position during the entire instructions phase of the test. If they step out, stop your instructions and require them to regain the starting position. Remind them that their ability to follow simple instructions is paramount to establish their level of sobriety. Note each time they sway, hop, raise their arms or step out of the starting position for your report. These are not “clues” to be scored, but are observations to indicate their impaired state. More on that later.

If the tested subject is wearing awkward shoes (high heels, cowboy boots, etc.) you should ask them if they want to take the test in their shoes or take their shoes off. Let them decide and get a verbal commitment either way. This shows your impartiality in conducting the test, and a genuine allowance on behalf of the subject. Trust me, the impaired driver will give you plenty of clues of impairment without resorting to trickery.


Like the other tests, I always start by giving the subject a basic description of

what I expect them to do. This looks great in court because the instructions are simple, and it gives me time to think about what I am saying and doing. If you ever get tongue- tied during instructions you can always pause and ask the subject “DO YOU UNDERSTAND?” During this time I will position myself about 10 feet away from the subject so that they can clearly observe my demonstration, and I can clearly observe any clues that the subject exhibits.

The basic instructions should hit the main points of the test. I inform the subject that when I tell them to begin they will balance on one foot, while raising the other foot approximately six inches off the ground. They will then count out loud in a manner that I will describe, and continue to count until I tell them to stop. That’s it! Simple and too the point.

I then ask the subject, “DO YOU UNDERSTAND?” After getting a verbalacknowledgment that they understand I move on to the next part of the instructions. Remember, if the subject says they don’t understand, ask them specifically what it is they don’t understand. Do not repeat all of the instructions again, simply repeat and clarify the part of the instructions that they do not understand. Always end with asking them “DO YOU UNDERSTAND?”


During the demonstration part of the instructions I will assume the same starting position that I have placed them into, about 10 feet in front of them. I will then explain that they will stand on the foot of their choosing and raise the other foot approximately six inches off the ground. At that time I will raise one of my feet about six inches off the ground. You need to practice this so that you know how to balance with all your duty gear on, and give an appropriate six inch example – this is important. I will also explain that they need to keep both legs straight during the test. Bending either or both legs during the test makes balancing much easier so you must watch for this and correct it if it begins to happen while you are scoring the subject.

Once I have my foot six inches off the ground I will explain and demonstrate that they need to point the toes of their raised foot so that the foot is parallel to the ground. This is a part of the divided attention test so do not let them cheat on this.

After placing my foot in the proper position I will advise the subject that they will begin counting in this manner, “one thousand one, one thousand two, one thousand three, and so on until I tell you to stop”. I will remind them that during the test they need to keep their arms down to their sides, and keep both legs straight. I will then ask them, “DO YOU UNDERSTAND?” After getting a verbal acknowledgment I will lower my raised foot and finish out the instructions.

Here’s a cheat for you to help you in your demonstration. If you find yourself off balance then slightly bend the leg you are standing on. Don’t make it obvious, but a slight bend will give you greater balance. Once you’ve done this, move your raised foot slightly towards the leg you are standing on, maybe even as far as directly in line with the leg your standing on. This will put your body more in line with itself and therefore more balanced. During the instructions you should be watching the subject – DO NOT LOOK DOWN. Looking up (on the horizon) makes it a lot easier to balance then looking down at your raised foot.


Now you are ready to give the person the final set of instructions. Like the WAT

test, do not try to mix the final instructions into the demonstration. More officers fail doing this and lose confidence in themselves and the tests because they try to cram too much information in while trying to maintain their balance. Unless you have high-wire balance naturally you are bound to lose your balance or rush the instructions (forgetting some along the way). Either way it makes you look foolish and unprepared. By breaking the test instructions into four distinct parts you can avoid the overwhelming pressure to throw everything at them at one time. Dividing the instructions into these four parts is also incredibly powerful in the courtroom because it makes the test easy to understand for judge and jury alike.

The final set of instructions uses the “head-to-toe” method to remember what you are going to instruct.

HEAD – Instruct them to look down at their raised foot during the test.

MOUTH – Remind them to count out loud “just like I did”, until you tell them to stop.

ARMS – Their arms are to remain at their sides during the entire test.

FEET – Keep the raised foot pointed and six inches off the ground during the entire test.

From experience I have added an instruction about what to do if they put their foot down during the test. Too often when a subject drops their foot the first time, they simply stop performing the test – like the first time they step off the line in the WAT test. To remedy that problem I give this final instruction – “if you happen to put your foot down during the test, regain your balance, raise your foot back into position, and continue counting where you left off.”

Before starting the test I will ask them one more time “DO YOU UNDERSTAND?” At a minimum I have asked them if they understand four different times, and I have not continued with instructions before getting four separate acknowledgments that they do in fact understand – great stuff in court. Be careful here. Do not accept head nodding or grunting as an acknowledgment. Request them to say “yes” or “I understand” or some other form of clear acknowledgment. Then the are locked in! At this point you are ready to have the subject begin the test.

The NHTSA Manual recognizes four (4) validated clues of impairment on the

OLS test. If you see two (2) or more clues then there is a high probability that the subject is impaired. All of the clues are found during the performance stage of the test, but if the subject exhibits lack of balance or the inability to follow instructions during the instructional phase those observations should be documented.


  1. Sways while balancing – Being fair the sway should be more than one inch off center.
  2. Raises arms for balance – more than six inches from their sides.
  3. Hops – moving the foot they are balancing on is a “hop”.
  4. Puts foot down – try to note on what count they did this, and how many times.

Swaying – you should stand in a position that allows you to observe the subject and some stationary object in the background. This could be a utility pole, a tree, a billboard, or even your patrol car. This gives you the basis of how you measured the sway the subject exhibited. I’ve been asked this in court so be prepared to have a solid answer. Note the type of sway as well – front to back, side to side, or circular (orbital).

Raises arms for balance – requires you to observe the subject raise one or both arms more than six (6) inches from their sides. Document on what count they raised their arms and how many times they raised their arms. If they raise their arms 30 times remember that it is only scored as one clue, performed 30 times.

Hops – is probably one of the most incorrectly scored clues simply because too many officers are looking for the “bunny hop”. The subject does not have to jump off the ground like a pogo stick to be scored for hopping. What is most often observed is the

subject begins shifting on the leg they are balancing on to try to counter the movement of their raised leg or body. Even if the foot doesn’t completely leave the ground, their body movement is causing their foot to temporarily lose traction and position with the ground. Think about what that looks like from a ground-level perspective. In order for the subject to move out of position their foot is coming up enough to allow movement, when their entire body weight is on that foot – that’s hopping, score it!

Puts foot down – No brainer here. Note on what count and how many times the subject puts their foot down. One thing to be careful of is to make sure the subject returns their foot to (6) inches with a pointed toe after they’ve put it down once. And make sure they look at their foot – the subjects will quickly start doing cheats once they realize their balance is poor.

By the completion of the three validated sobriety tests you should be more than comfortable with the arrest/no-arrest decision. If done properly these tests have been proven to be incredibly accurate in identifying driver’s that are at the .08% B.A.C. level or above. The sharper you hone your skills in administering these tests, the greater the success rate you will have in snatching the .08% and .09% impaired drivers off the road. Anyone can locate the .15% driver, but a true professional is required to remove the threats posed by drivers with lower B.A.C. levels.

One final reminder – from the first observation of the Vehicle In Motion you should start preparing yourself for the lawyer-savvy subject who will not talk to you or perform your tests. Tune in all your senses to document the many minor details that intoxicated drivers will give you during Vehicle In Motion and the Personal Contact phases of D.U.I. investigations. That way Mr. Refuse-all doesn’t slip by, and you’re detailed reporting of observed actions will be sufficient to gain the conviction in court.

Happy Hunting!

Aaron is a sergeant with a midwestern police department, where he serves as a trainer, supervisor and SWAT sniper. In addition to his broad tactical knowledge, Aaron has experience in DUI, DRE and undercover narcotics investigations.

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Richard Johnson is a gun writer, police trainer and really bad joke teller. Check out his other writing on sites like Human Events, The Firearm Blog and Police & Security News.

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