DUI Lawyer | Joel Brand, Esq.

Field Sobriety Test: One-Legged Stand

The One-Legged Stand test is one of the standardized field sobriety tests (SFSTs) used by law enforcement officers to determine whether a driver is impaired by alcohol or drugs. This test, along with the Walk-and-Turn and the Horizontal Gaze Nystagmus tests, was developed by the National Highway Traffic Safety Administration (NHTSA) to provide a systematic and standardized method for detecting impairment.

Understanding the One-Legged Stand Test

The One-Legged Stand test is designed to assess a person’s balance and coordination, which are often impaired by alcohol consumption. The test involves two stages: the instruction stage and the performance stage.

  1. Instruction Stage: During this stage, the officer provides clear instructions to the driver on how to perform the test. The driver is asked to stand with their feet together and arms at their sides while listening to the instructions. This stage allows the officer to observe the driver’s ability to follow simple instructions and maintain balance.
  2. Performance Stage: The driver is asked to raise one leg approximately six inches off the ground, keeping the foot parallel to the ground. The driver must then count aloud (e.g., “one thousand one, one thousand two”) while looking at the raised foot. This position must be held for about 30 seconds. The officer will watch for signs of impairment, such as swaying, using arms for balance, hopping, or putting the foot down.

Administration of the One-Legged Stand Test

The One-Legged Stand test must be administered under specific conditions to ensure its reliability and accuracy. According to NHTSA guidelines, the test should be conducted on a flat, dry, and well-lit surface. The officer must provide clear instructions and demonstrate the test before asking the driver to perform it. Proper administration is crucial as improper conditions or instructions can affect the test’s outcome and the driver’s performance.

Observations and Clues of Impairment

During the performance stage, the officer will observe the driver for four specific clues of impairment:

  1. Swaying while balancing: The driver sways while trying to maintain balance.
  2. Using arms to balance: The driver raises their arms more than six inches from their sides to maintain balance.
  3. Hopping: The driver hops to maintain balance.
  4. Putting the foot down: The driver puts their foot down before the 30-second count is completed.

NHTSA research indicates that if a driver exhibits two or more of these clues, there is a high likelihood that their BAC is 0.08% or higher. However, it is important to note that this test, like all field sobriety tests, is not foolproof and can be influenced by various factors.

Factors Affecting the One-Legged Stand Test

Several factors can affect a driver’s performance on the One-Legged Stand test, leading to potential false positives. These factors include:

  1. Medical Conditions: Certain medical conditions, such as inner ear problems, neurological disorders, or leg injuries, can affect balance and coordination. Drivers with such conditions may struggle with the test regardless of alcohol consumption.
  2. Age and Weight: Older individuals or those with higher body weight may have more difficulty performing the test due to natural declines in balance and agility.
  3. Environmental Conditions: Uneven, slippery, or poorly lit surfaces can make the test more challenging and affect the driver’s performance.
  4. Footwear: Wearing high heels, flip-flops, or other unstable footwear can impede a driver’s ability to balance.
  5. Nervousness or Anxiety: Being stopped by law enforcement can cause significant stress and anxiety, affecting a driver’s ability to perform the test accurately.

Challenging the One-Legged Stand Test in Court

Given the potential for various factors to influence the outcome of the One-Legged Stand test, challenging its results in court can be an effective defense strategy. A skilled DUI attorney can scrutinize the administration of the test and the conditions under which it was performed to identify any inconsistencies or errors.

  1. Improper Administration: The attorney can argue that the test was not administered according to NHTSA guidelines. This includes demonstrating that the officer failed to provide clear instructions, did not use a suitable testing surface, or did not account for the driver’s medical conditions or footwear.
  2. Lack of Probable Cause: If the officer did not have reasonable suspicion to stop the driver initially, any evidence gathered from the stop, including the results of the One-Legged Stand test, may be deemed inadmissible in court.
  3. Alternative Explanations: The attorney can present evidence of alternative explanations for the driver’s performance, such as medical records indicating a balance disorder or testimony about adverse weather conditions at the time of the test.

Conclusion

The One-Legged Stand test is a widely used tool in DUI investigations, designed to assess a driver’s balance and coordination. However, its reliability can be compromised by various factors, from medical conditions to environmental conditions. Understanding the test’s limitations and the factors that can influence its outcome is crucial for effectively challenging its results in court.

A knowledgeable DUI attorney can scrutinize the administration of the test, identify potential errors, and present alternative explanations to contest the test’s validity. By doing so, the attorney can help protect the driver’s rights and work towards a favorable outcome in the case.

Citations

  1. National Highway Traffic Safety Administration, DWI Detection and Standardized Field Sobriety Testing (SFST) Manual, https://www.nhtsa.gov/sites/nhtsa.dot.gov/files/documents/sfst_full_instructor_manual_2018.pdf
  2. California Vehicle Code § 23152(a)
  3. National Institute on Alcohol Abuse and Alcoholism, Alcohol’s Effects on Balance, https://www.niaaa.nih.gov/alcohols-effects-balance