What aspect of the One-Leg Stand do officers closely monitor?

In the One-Leg Stand test, officers closely monitor the subject's ability to maintain balance without putting the foot down. This component is critical because it serves as one of the key indicators of a person's impairments related to alcohol or drug use. During this test, the person is asked to stand on one leg for a specified duration while counting or looking at their foot. If the person is unable to maintain balance and puts their foot down, it suggests a lack of coordination and stability, which are common signs of impairment.

While other factors, such as adherence to instructions and eye focus, may also provide some context about the subject's condition, the core focus of this part of the Standardized Field Sobriety Test is specifically on balance, as it is a direct reflection of motor skills that can be affected by intoxication.