The One Leg Stand (OLS) test constitutes the third field sobriety test in the standardized battery, yet its effectiveness as a reliable indicator of intoxication remains highly questionable. Despite law enforcement's reliance on this test, fundamental flaws in its design, administration, and interpretation cast serious doubt on its validity.

The Structure and Demands of the OLS Test

The OLS test consists of two phases: the instruction stage and the balance and counting stage. During instruction, subjects must stand with feet together and arms at their sides while receiving directions. The performance phase requires lifting one foot approximately six inches off the ground, maintaining this position for 30 seconds while counting aloud "one thousand one, one thousand two," and so forth.

This test places extraordinary demands on physical balance, coordination, and divided attention—capabilities that vary tremendously among the population regardless of alcohol consumption.

Questionable Scientific Basis

The claimed 83% accuracy rate for the OLS test stems from the same problematic research that validated other field sobriety tests. Conducted under artificial laboratory conditions in the late 1970s and early 1980s, these studies fail to reflect real-world roadside scenarios. The controlled environment, cooperative subjects, and ideal testing conditions bear no resemblance to nighttime traffic stops on busy highways or poorly lit side streets.

Fundamental Design Problems

The OLS test's very structure creates significant opportunities for error unrelated to alcohol impairment. Standing on one leg for 30 seconds while counting challenges many completely sober individuals. The test requires sustained concentration, physical stamina, and balance that may be compromised by numerous factors beyond alcohol consumption.

Even the original research acknowledged that individuals over 65, those overweight by 50 or more pounds, and people with various medical conditions would struggle with this test regardless of sobriety. Yet officers routinely administer the test without considering these critical limitations.

Environmental Challenges

Real-world conditions severely compromise test reliability. Officers frequently conduct the OLS test on surfaces that violate the test's own guidelines. Sloped pavement, gravel shoulders, wet or icy conditions, and poorly illuminated areas all affect performance. Wind, passing traffic, and environmental distractions further undermine the test's validity.

Despite clear instructions that the test should occur on "a reasonably dry, hard, level, non-slippery surface," officers often proceed in suboptimal conditions, virtually guaranteeing compromised results.

Medical and Physical Factors

Numerous conditions unrelated to alcohol can impair OLS performance. These include inner ear disorders affecting balance, knee or ankle injuries, back problems, neurological conditions, arthritis, muscle weakness, and simple fatigue. Footwear also plays a crucial role—high heels, boots, or ill-fitting shoes can significantly impact balance.

Anxiety, common during police encounters, can cause trembling or loss of balance. Officers rarely distinguish between anxiety-induced instability and alcohol impairment, leading to false conclusions about intoxication.

Subjective Clue Interpretation

The test relies on officers identifying four possible clues: swaying while balancing, using arms for balance, hopping, and putting the foot down. Each clue requires subjective judgment. How much movement constitutes "swaying"? What degree of arm motion qualifies as "using arms for balance"? Different officers may reach vastly different conclusions observing identical performances.

This subjectivity introduces significant potential for bias, particularly when officers have already formed opinions about a subject's impairment based on other observations.

Challenging OLS Results in Court

Experienced DUI defense attorneys employ comprehensive strategies to challenge OLS evidence. The defense begins with scrutinizing video footage for administration errors. Many officers fail to provide proper demonstrations, rush through instructions, or conduct the test in inappropriate locations.

Cross-examination targets the officer's subjective interpretations and potential confirmation bias. Attorneys probe whether officers considered non-alcohol factors, how they distinguished between different causes of imbalance, and whether they properly timed the 30-second performance period.

Defense strategies often include demonstrating the test's inherent unfairness. Attorneys may ask jurors to consider performing the test themselves under similar conditions—nervous, tired, possibly wearing uncomfortable shoes, with traffic rushing by. This approach helps jurors understand how easily sober individuals can fail the test.

Additionally, attorneys educate courts about the test's scientific limitations. They present research questioning its validity, highlight the absence of peer-reviewed studies supporting its use, and emphasize how the test measures physical capabilities rather than intoxication.

Critical Considerations

The One Leg Stand test, despite its official status, remains a deeply flawed assessment tool. Its susceptibility to environmental conditions, failure to account for individual physical differences, and reliance on subjective interpretation make it an unreliable indicator of alcohol impairment.

Time constraints further compromise the test's validity. The original research indicated that individuals with BACs above 0.10 could often maintain balance for 25 seconds, suggesting the 30-second requirement serves more to induce failure than accurately assess impairment.

Those facing DUI charges based on OLS results should understand these significant limitations. A skilled defense attorney can expose the test's weaknesses, challenge its administration, and present compelling alternative explanations for poor performance. Given the serious consequences of DUI convictions, accepting OLS results without vigorous challenge represents a dangerous concession to flawed science.

Ohio OVI Defense Attorneys

This article provides general information only and does not constitute legal advice. Each case presents unique circumstances requiring individualized legal consultation.