How might a subject show impairment during the Walk-and-Turn test?

The Walk-and-Turn test is a standardized field sobriety test specifically designed to assess an individual's balance, coordination, and ability to follow instructions, all of which can be compromised by alcohol or drug impairment. A subject exhibiting impairment may demonstrate their condition through various physical behaviors during this test.

Taking an incorrect number of steps or stepping off the line directly reflects an inability to maintain the precise coordination required to perform the task correctly. The test requires the individual to walk heel-to-toe in a straight line for nine steps, turn around, and walk back in the same manner. Deviating from these instructions—such as taking more or fewer steps than required or stepping off the marked line—indicates problems with balance and cognitive processing, both common signs of impairment.

The other behaviors, while they may indicate some difficulty, do not specifically demonstrate the failure to follow the structured requirements of the test as clearly as the inability to take the correct number of steps or maintain the walking line does. Therefore, the manifestation of impairment in the context of this standard test is best exemplified by those specific actions.