The One-Leg Stand test is a divided attention test that requires the subject to perform both mental and physical tasks simultaneously. Alcohol or drug impairment can hinder a person’s ability to divide their attention effectively, leading to observable errors. However, as with other field sobriety tests, factors unrelated to impairment can also influence the outcome, which is why this test’s results are not definitive proof of intoxication.
How the One-Leg Stand Test Is Administered
The One-Leg Stand test consists of two phases: the instruction phase and the balance and counting phase. The officer observes the subject during both phases to identify specific signs of impairment.
Instruction Phase:
- The officer instructs the subject to stand with their feet together and arms at their sides.
- The officer demonstrates the test, explaining that the subject will raise one leg approximately six inches off the ground, keeping the leg straight and toes pointed outward.
- The subject is instructed to maintain this position while counting aloud in the format of “one thousand one, one thousand two...” until told to stop (usually for a duration of 30 seconds).
Balance and Counting Phase:
- The subject lifts one leg as instructed and begins counting.
- The officer observes the subject closely for any of the following four clues of impairment:
- Swaying while balancing.
- Using arms for balance.
- Hopping to maintain balance.
- Putting the foot down before the test is completed.
If the officer observes two or more clues, it suggests a 65% likelihood that the subject has a BAC of 0.08 or higher, according to NHTSA research.
Scientific Basis and Limitations
The One-Leg Stand test is designed to assess both physical coordination and mental focus, two areas that alcohol and drug impairment can significantly affect. However, it is not a perfect measure, and several factors can compromise its accuracy:
- Physical Conditions: Individuals with balance issues, injuries, obesity, or certain medical conditions (such as inner ear problems) may struggle with the test even when sober.
- Environmental Factors: Uneven pavement, poor lighting, or adverse weather conditions can make it challenging to perform the test as instructed.
- Improper Instructions or Administration: Officers must strictly follow NHTSA protocols. Failure to provide clear instructions, allow the subject to remove unsafe footwear, or conduct the test in a suitable location can invalidate the results.
- Stress and Anxiety: Many individuals find the test intimidating or stressful, which can lead to mistakes unrelated to impairment.
Defending Against One-Leg Stand Test Results
When defending DUI cases involving the One-Leg Stand test, it is essential to scrutinize every detail of the test’s administration and the surrounding circumstances. A skilled DUI defense attorney can raise questions about:
- Whether the officer followed proper procedures and training.
- The physical and environmental conditions under which the test was conducted.
- The individual’s medical history or physical limitations that could have influenced their performance.
Why the One-Leg Stand Test Alone Is Insufficient
It’s important to emphasize that the One-Leg Stand test is not a pass/fail exam and cannot conclusively prove impairment. It is merely a tool to help officers detect potential impairment and determine whether further testing, such as a breathalyzer or blood test, is warranted. Courts in South Carolina recognize the limitations of SFSTs and often require corroborating evidence to support a DUI charge.
Call Us Now
If you are facing DUI charges in South Carolina, you need an experienced attorney who understands the complexities of field sobriety tests like the One-Leg Stand. At the Law Office of James R. Snell, Jr., LLC, we have extensive experience defending clients against DUI charges and challenging the reliability of SFSTs. James Snell is the author of South Carolina DUI Defense: The Law and Practice and a certified NHTSA DWI Detection and Field Sobriety Testing instructor. He has successfully represented hundreds of clients in Lexington, Columbia, and throughout South Carolina.
Don’t let a DUI charge jeopardize your future. Call us today at (803) 359-3301 for a free consultation. We will take immediate steps to protect your license, freedom, and reputation and provide you with the strong defense you deserve.