What are the two stages of the One-Leg Stand (OLS) test?

The two stages of the One-Leg Stand (OLS) test are indeed balance and instruction.

During the instruction stage, the officer demonstrates how the test should be performed and explains the requirements to the subject. This includes showing them how to stand on one leg while counting aloud and keeping their arms at their sides. Clear and concise instructions are crucial for ensuring that the subject understands what is expected of them.

In the balance stage, the subject attempts to maintain their balance while standing on one leg for a designated period, usually 30 seconds. The officer observes the subject for any signs of impairment, such as swaying, using their arms for balance, or putting their foot down. These observations help in assessing the subject's level of impairment, which can be indicative of alcohol or drug influence.

This structure is vital for the correct administration of the test, as it helps ensure standardized evaluations and reliable results.