Updated: May 31
The One Leg Stand, or, OLS, in law enforcement-speak, is one of a number of standardized field sobriety tests (SFSTs) that patrol officers are trained to use to test drivers suspected of impairment.
The National Highway Traffic Safety Administration (NHTSA) trains law enforcement academy instructors to administer this test at the roadside to discern “clues,” or, signs of insobriety that its commissioned research concluded correlate to breath alcohol content (BrAC) percentages over .10 grams per 210 L breath. I note that the research used to support this test was largely conducted before the States moved to the lower .08 grams per 210 L breath standard but that a Colorado study commissioned by the National Highway Traffic Safety Administration purports to validate the testing procedures and the standard battery of tests to lower BrACs including the standard in effect at that time in Colorado for a “lite” DUI offense of .05 grams per 210 L breath.
Certainly, a trained expert retained by defendants and qualified to testify in Iowa courts can argue against the value of these tests given that original studies validated them for BrACs of .10 or higher and redux testing purportedly validated them for testing of .05 grams per 210 L breath or higher, suggesting that the testing will produce false positives for those between .05 and .08 BrAC. Courts in Iowa do not criminalize BrAC’s less than .08 so the tests produce false positives. Even the testing’s authors acknowledge that roadside testing is not a substitute for a breath, urine, or blood test, given the complexity of the driving task. And those test’s advocates also acknowledge that the tests produced false positives even within their artificial parameters—arrests for those whose breath alcohol fell below impermissible levels. In any case, the science of field sobriety testing has become an accepted part of the pseudoscience of drunk driving prosecution in Iowa and it is something with which we must contend.
Of that testing, the final physical agility test is the OLS. The OLS is a test whereby the officer advises a defendant to raise one leg, whichever leg the test subject chooses, and hold their foot level to the payment approximately six inches above the ground while counting out loud and adding “one thousand” between each second, as in, one, one thousand, two, one thousand, three one thousand, etc.
The officer looks for swaying, putting a foot down, and using arms to balance. The test is measured in three ten second segments. The officer will allow a test subject to count to thirty if safety allows. They can stop the test if the administrator believes a test subject will fall or otherwise hurt themselves.
The original research commissioned by this test’s proponents concluded that it was only sixty-five percent effective at correlating poor test performance with BrAC levels of .10 grams per 210 L breath or more. The research also suggested that even an impaired driver can hold up their foot for twenty-five seconds so the thirty seconds is important to test administrators.
If you or a loved one has been arrested for OWI (DUI) in the State of Iowa, contact us for a free initial consultation and chart a course back to life before the crisis. However, remember that a blog is not legal advice and that sending unsolicited information to an attorney over the Internet does not established an attorney-client relationship.