The one-leg stand test is a standardized field sobriety test (SFST) that police often administer as a means to determine whether a DUI suspect is under the influence of alcohol or drugs.
In the one-leg stand test, officers instruct the suspect to stand with one foot approximately six inches off the ground and count aloud by thousands (one-thousand-one, one thousand-two, etc.) until told to put the foot down (which should happen after 30 seconds).1
The suspect is further instructed to keep his eyes on the elevated foot and keep his arms by his sides while performing the test.2 If the suspect
- uses his arms to balance,
- hops, and/or
- puts his foot down,
then he may be suspected of having a high blood alcohol concentration.3
According to the National Highway Transportation Safety Administration (NHTSA), studies have revealed the one-leg stand test to be 65% accurate in determining whether a driver has a blood alcohol concentration above .10.4
NHTSA has laid out meticulous methods for officers to follow when administering the one-leg stand test, as well as indicators to look for in scoring the test.
Nonetheless, officers frequently administer the test incorrectly, thereby leaving the testing process open for further criticisms and inaccuracies.
Consequently, drivers find themselves at risk of being wrongly arrested based on an unreliable field sobriety test.
In the article below, our California DUI defense lawyers will explain:
The one-leg stand test is a “divided attention” test.5 This means that the suspect’s attention is simultaneously divided between mental and physical tasks.
The one-leg stand test is specifically designed to have an individual listen to, follow and remember instructions while performing simple physical movements (i.e. maintaining a stance).6
The one-leg stand test is one of three standardized field sobriety tests (SFSTs). The other two standardized field sobriety tests are
These three tests are considered “standardized” mainly because they have been the focus of various scientific studies noticeably establishing the connection between the three tests and DUI impairment.7
Nonetheless, law enforcement officials often depend on both standardized and non-standardized FSTs to assist in their DUI investigations.
These non-standardized FSTs include
Out of all the standardized field sobriety tests administered by law enforcement officials, the one-leg stand test has proven to be the least scientifically reliable.8
Unsurprisingly, Senior DUI/DWI Field Sobriety Test Instructor Robert “Bob” LaPier argues that the one-leg stand test should take a back seat to the other two SFSTs, especially the horizontal gaze nystagmus test.
Having taught thousands of polices officer and hundreds of attorneys (both DUI defense lawyers & prosecutors) in the proper administration of standardized and non-standardized field sobriety tests, Mr. LaPier firmly believes that the HGN test should be the centerpiece of any effective DUI field investigation.
Nevertheless, the one-leg stand test has been and continues to be validated through NHTSA’s research program. Therefore, it still carries a great deal of weight, especially when offered along with the other field sobriety tests.
However, as noted by our California DUI defense lawyers in subsection five, the one-leg stand may very well be a critical source of deception and error in DUI investigations.
Below are the one-leg stand test instructions given by the National Highway Traffic Safety Administration (NHTSA), to DUI law enforcement officers on how to administer the one-leg stand sobriety test:
Provide the DUI suspect the instructions listed below and from a position of interrogation (that is, with your weapon away from the suspect):
STAND WITH YOUR HEELS TOGETHER AND YOUR ARMS DOWN AT YOUR SIDES LIKE THIS
- Demonstrate how you want the suspect to stand.
WHEN I TELL YOU, RAISE ONE LEG ABOUT SIX INCHES OFF THE GROUND AND HOLD THAT POSITION. AT THE SAME TIME COUNT RAPIDLY FROM 1001 TO 1030, WHILE WATCHING YOUR FOOT
- Demonstrate this to the suspect (officer should not look at his foot when conducting the demonstration-Officer Safety).
DO YOU UNDERSTAND?
- Do not continue until the suspect indicates that he understands.
BEGIN BY RAISING EITHER YOUR RIGHT OR YOUR LEFT FOOT.
- At the end of the count or after about 30 seconds, if the count is slow, tell the person to put his foot down if necessary.9
These steps are visually laid out in the following NHTSA approved One-Leg Stand Test Video.
The One-Leg-Stand test must be administered under safe and appropriate test conditions. In particular, there are two main test conditions that law enforcement officials must keep in mind:
- Surface Conditions:
- The one-leg stand test should be given on level ground, on a hard, dry, non-slippery surface, and under conditions in which the DUI suspect will be in no danger should he or she fall.
- If these guidelines cannot be followed at the place where the driver is stopped, then the officer should try to move the suspect to a better location.10
- Lighting Conditions:
- In administering the one-leg stand test, the officer should make sure the DUI suspect’s eyes are open and that adequate lighting exists. If the suspect can see the officer fairly well, then the lighting is adequate.
- Otherwise, the officer should use a flashlight to illuminate the ground. In total darkness, the OLS is obviously difficult even for a sober person.
In order to gauge whether a driver is intoxicated, law enforcement officials will typically watch for four major “clues” of intoxication during the administration of the one-leg stand test.
Keeping these clues in mind, officers will then give one point for each clue that is spotted. Since there are four total clues, there is a total of 4 points potentially given out during the testing. If the DUI suspect scores two or more points out of the four possible points on this test, officers will classify his or her BAC as above 0.10 percent.11
Using this criterion, officers will correctly classify about 65 percent of their suspects with respect to whether they are drunk driving.12 That probability had been determined during limited laboratory and field-testing and is given simply to help an officer weigh the various sobriety tests as he makes a decision whether to arrest the suspect.13
The One-Leg Stand Test Scoring Sheet composed of the major clues of intoxication is as follows:
- CLUE 1: The suspect sways while balancing-This refers to side-to-side or back-and-forth motion while the suspect maintains the one-leg stand position.
- CLUE 2: Uses arms for balance-Suspect moves arms 6 or more inches from the side of his or her body in order to maintain balance.
- CLUE 3: Hopping-Suspect is able to keep one foot off the ground, but resorts to hopping in order to maintain balance.
- CLUE 4: Puts foot down-The suspect is not able to maintain the one-leg stand position, putting the foot down one or more times during the 30-second count.*If the suspect puts his or her foot down three or more times during the 30-second period, then he or she will be deemed to have failed the test.14
According to government-sponsored studies, the one-leg stand test is deemed to be only 65% accurate in determining whether a driver has a blood alcohol concentration above .10.15 This essentially means that more than one out of three people who fail the test are NOT intoxicated.
Significantly, this ratio is based on the assumption that the one-leg stand test is administered properly in accordance with NHTSA guidelines. In reality, however, not only does the test carry its own inherent flaws, but its administration by law enforcement officials, including the California Highway Patrol (CHP) and the Los Angeles Police Department (LAPD), often fall short of NHTSA standards.
As Rancho Cucamonga DUI defense lawyer Neil Shouse16 says, “Clearly, the reliability of the one-leg stand test is in serious question. Any good DUI defense attorney should therefore be able to expose several weaknesses in the procedures/ administration of the one-leg stand test in a DMV hearing and/or in the courtroom.”
Some of these weaknesses ripe for attack by our California DUI defense lawyers include:
1. Unfair surface conditions:
- The One-Leg Stand test requires a reasonably dry, hard, level, and non-slippery surface. Without all of these factors in place, any test results may be deemed invalid.17
2. Physical and/or mental impairments:
- If a suspect is over 60 years of age, has any back, foot, leg, inner ear problems, or even if the suspect is overweight by 50 or more pounds-these physical impairments, along with a countless list of others-may inaccurately skew the results towards failure.
- Alternatively, if a suspect has any brain damage or suffers from any mental disabilities that would inhibit his ability to comprehend and/or follow instructions, then the test results would again be highly dubious.18
3. Improper timing:
- Timing is critical in this test. While research has shown that many impaired suspects may be able to successfully perform the one-leg stand for up to 25 seconds, few are able to do so for 30 seconds.19 If the officer does not time the test with a watch and/or in any way starts/ends the timing incorrectly, then the test results may not be valid.
4. Officer movement:
- The officer is supposed to remain as motionless as possible during the test so as not to interfere with it. If an officer, however, decides to walk around or exhibit any other forms of distractive behavior during the testing, then the results may be deemed tainted.20
5. Unsuitable footwear:
- If a suspect had been wearing heels more than two inches high at the time of the test, then the officer should have given her the opportunity to remove her shoes. Moreover, if a suspect had been wearing tight leather pants or baggy/beltless jeans or any other type of clothing that inhibited his or her ability to maneuver during testing, then the test results may be tainted.21
6. Flamingos, Seagulls, and Geese—The “unhuman” nature of the one-leg stand test:
- From childbirth, we as humans are trained to stand on two feet. While certain animals may find it second-nature to stand on one foot, this is certainly not true of the human species. Hence, any performance failures may be attributed to the inherently “unnatural” bird-like demands of the test.
Call us for help…
If you or a loved one is charged with a DUI and you are looking to hire an attorney for representation, we invite you to contact us at Shouse Law Group. We can provide a free consultation in office or by phone. We have local offices in Los Angeles, the San Fernando Valley, Pasadena, Long Beach, Orange County, Ventura, San Bernardino, Rancho Cucamonga, Riverside, San Diego, Sacramento, Oakland, San Francisco, San Jose and throughout California. For information about the Nevada one leg stand test, see our article on the Nevada one leg stand test.
1 U.S. Department of Transportation “DWI Detection and Standardized Field Sobriety Testing” NHTSA Student Manual (February 2006): VII/6
2 Id., at VII/6
3 Id., at VII/6
4 Stuster & Burns, Validation of the Standardized Field Sobriety Test Battery at BACs Below .10 percent. U.S. Dept. of Transportation Rep. No. Dot-HS-808-839 (1998),
5 Id., at 32.
6 Id., at 32. Suspects who are intoxicated tend to have difficulty with tasks that require their attention to be divided between mental and physical tasks.
7NHTSA Student Manual (2006), at VIII/1; See also Burns & Moskowitz, Psychophysical Tests for DWI Arrest, U.S. Dept. of Transportation Rep. No. DOT-HS-802-424 (1977) (recommended the three-test battery of one-leg stand, walk and turn, and HGN to aid officers in discriminating BAC level); Anderson, Schweitz & Snyder, Field Evaluation of Behavioral Test Battery for DWI, U.S. Dept. of Transportation Rep. No. DOT-HS-806-475 (1983) (field evaluation of the field sobriety test battery (HGN, one-leg stand, and walk and turn) conducted by police officers from four jurisdictions indicated that the battery was approximately 80% effective in determining BAC above and below .10 percent).
8 Id., at VIII/1
9 Id., at VIII/12
10 Id., at VIII/13-14
11 Id., at VII/6
12 Id., at VII/6
13 Id., at VII/6-7; See also Burns & Dioquino, Field Evaluation Study of the Standardized Field Sobriety Test (SFST) Battery, (Florida, 1997). Study demonstrated that officers trained under NHTSA guidelines and experienced in application of the SFST battery in the field were accurate in 95% of arrest decisions and 85% of release decisions.
14NHTSA Student Manual (2006), at VII/7
15 Id., at VII/7
16 Rancho Cucamonga DUI defense lawyer Neil Shouse is a former Los Angeles County prosecutor who now defends clients accused of drunk driving throughout Southern California.
17 Id., at VIII/13
18 Id., at VIII/14
19 Id., at VIII/13
20 Id., at VIII/13
21 Id., at VIII/14