One Leg Stand Flashcards

A subject raises one foot approximately 5 inches off the ground during OLS instead of the required 6 inches. How should the officer proceed?

Answer: Note the deviation but continue observing for all four clues

Minor deviations in foot height do not invalidate the test; the officer continues observing and notes any non-compliance in their report.

Which leg should the subject raise during the OLS test?

Answer: Either leg, as the subject chooses

NHTSA standardization allows the subject to raise either leg; officers should note which leg was used in their report.

An officer observes a subject exhibit all four OLS clues within the first 10 seconds. Should the officer stop the test early?

Answer: No, the full 30 seconds should be completed unless safety requires stopping

The full 30-second test should be completed to maintain standardization and allow full documentation, unless continuing poses a safety risk.

For the OLS test to be scientifically valid, which of the following environmental factors must be considered?

Answer: Lighting, surface conditions, and ambient temperature

NHTSA guidelines require officers to evaluate lighting, surface conditions, and environmental factors that could affect balance before administering OLS.

During court testimony, a defense attorney asks why the officer did not use a stopwatch during OLS. What is the correct NHTSA-recommended response?

Answer: NHTSA recommends using a watch or other timing device to measure the 30-second period

NHTSA recommends that officers use a timing device to accurately measure the 30-second OLS period.

A subject who weighs 400 pounds wants to perform the OLS test. What does NHTSA guidance suggest?

Answer: People who are significantly overweight may have difficulty and results should be interpreted with caution

NHTSA acknowledges that individuals who are significantly overweight (50 or more pounds) may have genuine difficulty with OLS due to physical factors unrelated to impairment.

What is the purpose of having the subject stand with feet together and arms at sides BEFORE the OLS instructions begin?

Answer: To establish a starting position and observe initial balance

The heel-to-toe stance with arms at sides is the standardized starting position that allows the officer to observe baseline balance before the test begins.