One Leg Stand Field Sobriety Test
This field sobriety test is also a standardized field sobriety test (SFST) that all law enforcement doing DUI arrests is trained in, from the NHTSA manual.
The one leg stand requires the tested person to be place into the instructional position. They are told to stand with their feet together side by side, to keep the arms to the side of their body, and to remain in that position and not to begin the test until told to start.
The tested person is then asked if they understand up to this point. NHTSA says, “In the instructions stage, the subject must stand with their feet together keep arms at sides and listen to the instructions. This divides the subject’s attention between a balancing task (Maintaining a stance) and an information processing task (Listening and remembering instructions).
The one leg stand test requires the tested person to stand on the leg of their choosing, raise the other leg up in front of them approximately 6 inches off the ground while keeping both legs straight. While doing this the tested person is told to keep their arms to their side, point the toe of the elevated foot, look at the toe of the elevated foot, and count out loud by 1000’s until told to stop. This phase of the test is called the balance and counting stage. The test lasts for thirty seconds and is timed by the administrating Deputy.
NHTSA says, “In the balance and counting stage, The subject must raise one leg, either leg, approximately six inches off of the ground, toes pointed out, keeping both legs straight. While looking at the elevated foot, count out loud in the following manner, one thousand and one, one thousand and two, one thousand and three until told to stop.
This divides the subject’s attention between balancing (standing on one foot) and small muscle control” (counting out loud). (P.VII-4, NHTSA SFST Student Manual, 2002).
Instructions Stage: Initial Positioning and Verbal Instructions
Initiate the test by giving the following verbal instructions accompanied by demonstrations.
- Please stand with your feet together and your arms down at the sides like this (Demonstrate).
- Do not start the test until I tell you to do so.
- Do you understand the instructions so far? (Make sure suspect indicates understanding)
Demonstration and Instructions for the balancing and counting stage
Explain the test requirements using the following verbal instructions accompanied by demonstrations:
- When I tell you to start, raise on leg either leg approximately six inches off the ground foot pointed out (Demonstrate one leg stance).
- You must keep both legs straight arms at your sides.
- While holding that position, count out loud in the following manner, 1001 1002 1003 until told to stop.
(Demonstrate and count as follows: 1001 1002 1003 ext. Deputy should not look at his foot when conducting the demonstration for reasons of officer safety).
- Keep your arms at your sides at all times and keep watching the raised foot.
- Do you understand? (Make sure suspect indicates understanding)
- Go ahead and perform the test. (Deputy should always time the 30 seconds.
Test should be discontinued after 30 seconds).
(P.VIII-12, NHTSA SFST Student Manual, 2002)
“IT IS NECESSARY TO EMPHASIZE THIS VALIDATION APPLIES ONLY WHEN: THE TESTS ARE ADMINISTERED IN THE PRESCRIBED STANDARDIZED MANNER, THE STANDARDIZED CLUES ARE USED TO ASSESS THE SUSPECTS PERFORMANCE, THE STANDARDIZED CRITERIA ARE EMPLOYEED TO INTERPRET THAT PERFORMANCE. IF ANY ONE OF THE STANDARDIZED FIELD SOBRIETY TEST ELEMENTS IS CHANGED THE VALIDITY IS COMPROMISED” (P.VIII-19, SFST student manual, HS 178 R1/02).
THE STANDARDIZED FIELD SOBRIETY TESTS ARE NOT AT ALL FLEXIBLE. THEY MUST BE ADMINISTERED EACH TIME, EXACTLY AS OUTLINED IN THIS COURSE (P. 8, SFST Administrators Guide, HS 178 R1/02).
The One leg stand requires the tested person to stand on one leg for thirty seconds that is timed by the administrating Deputy.
NHTSA says, “Deputy should always time the thirty seconds. Test should be discontinued after thirty seconds” (P. VIII-12 NHTSA SFST Student Manual, 2002). How this Officer keeps track of the time is usually not included in the police report of most DUI arrests we see.
NHTSA uses the following clues of intoxication for scoring this test.
*Uses arms to balance
*Puts foot down
• Cannot perform test (test stopped or not requested for suspect’s safety); Assign all 4 clues.
TOTAL SCORE: (Decision Point: 2; Max: 4)
Scoring the Field Sobriety Test
As indicated above, the police officer looks for the specific clues of intoxication above, and if at least two of those exist, or the subject cannot perform the test, the officer may conclude that the person is above a 0.08% blood alcohol level.