Well, it's a pretty good indication of impairment, but it only works about two-thirds of the time. Even so, officials consider those odds good enough to make it one of the three tests that make up the Standardized Field Sobriety Test battery administered by officers here in California and across the country. In addition to the one-leg stand, the horizontal gaze nystagmus and the walk and turn tests round out the three tests that make up the SFST.
The primary issue with all three of these tests is that they require a subjective opinion from the officer administering them. To show how much the opinion of law enforcement officers can vary, several of them watched the same video of someone taking these tests. Some believed that the person in the video was impaired and some did not.
One study found that as many as 47 percent of people who underwent the test would have been arrested falsely. You may be thinking at this point that taking field sobriety tests may be a sort of DUI roulette, and you may be right.
Problems with the one-leg stand test
That last study was done under "ideal conditions," but when you get pulled over and are asked to participate in field sobriety tests, the conditions are likely far less than ideal. Instead, the conditions under which you take the test in real life would probably include some or all of the following:
- Flashing lights
These factors could easily cause you not to understand instructions from the officer and not be able to maintain your balance.
Let's take a look at that word... balance
The one-leg stand test assumes that you have a good sense of balance — but what if you don't. Many people have issues maintaining balance for a variety of reasons, some of which include the following:
- Blood pressure
- Inner ear infections
- Head trauma
- Brain issues
- Back, leg or foot issues
- Musculoskeletal issues
These or other factors could cause you to fail the one-leg stand test. Even if you had a couple of drinks, you may not necessarily be impaired, but because you failed the test, you end up under arrest on suspicion of drunk driving. You may want to simply decline to participate in the tests, but do so politely.
The officer may then administer a breath test. However, even breath tests have their flaws.
You retain the right to challenge the evidence that supposedly points to your guilt. This often includes several factors beginning with the traffic stop itself. You may not think it's important to go to these lengths for what may be charged as a misdemeanor, but considering that the ramifications could have unintended consequences to your personal and professional lives, you may want to reconsider. Enlisting the aid of a California criminal defense attorney could increase your chances of successfully challenging the validity and veracity of the evidence, including the one-leg stand test.