One Leg Stand
The Third Scientifically Validated Test according to NHSTA
Basics and Instruction Stage of One Leg Stand TestThis is the second most accurate SFST and, like the Walk and Turn, is a divided attention test. There are two stages, 1. Instruction 2. Balance and Counting. The divided attention part is listening to the instructions while maintaining balance.
Instructions Stage-Instructions must be done accurately:
1. Stand with your feet together arms down by your side
2. Demonstrate the position
3. Do not start the test until I tell you to do so
4. Do you understand (Need verbal response)
Balance and Counting Stage of the One Leg Stand TestBalance and counting Stage-Must be said and demonstrated accurately:
1. When I tell you to start, raise either leg with the foot approximately 6 inches off the ground, keeping your foot parallel to the ground. Demonstrate the position
2. Keep both legs straight and your arms at your sides.
3. While holding that position, , count out loud in the following manner: *one thousand one, one thousand two, one thousand three, and so on until told to stop. Officer demonstrates but does not look at feet while demonstrating
4. Keep your arms at your sides at all times and keep watching your raised foot. Major error if not told to watch raised foot
5. DO YOU UNDERSTAND/ (Need verbal response)
6. Perform the test . Officer times for 30 seconds
OFFICER MUST TIME 30 SECONDS-CHECK TO MAKE SURE THIS IS DONE.
IMPORTANT: This is of paramount importance to defense attorneys, prosecutors and LEO*s. If instructions are given wrong on the Walk and Turn and One Leg Stand then the subject cannot be penalized for doing it wrong, and officer*s credibility is affected. If instructions are left out, it affects the validity of the test, and if the subject is not asked if they understand and gives a verbal affirmative response then the test validity is affected.
Clues and Mistakes inScoring One Leg Stand TestAS THE PURPOSE OF THE SFST IS DETERRENCE, IT IS TO EVERYONE*S INTEREST TO MAKE SURE THEY ARE DONE CORRECTLY
There are four clues of impairment in the one leg stand.
1. Sways while balancing
2. Using arms to balance
4. Put foot down
Recent studies suggest that if an individual shows two or more clues in the One Leg Stand there is a good chance that the BAC is at or above .08
Aside 10: Other errors that can occur because of officer not remembering that the test are hard enough without other distractions;
1. Walking alongside subject
2. Other officers moving around
3. Giving instructions during test
4. Dictating or taking too loud
5. Other behavior that is obviously distractive to subject