Which action is assessed when testing for pronator drift?

Testing for pronator drift specifically assesses the movement of the palms when held out in front of the body. This clinical test is used to evaluate the upper motor function, particularly of the arms. When a patient extends their arms forward with palms up, any involuntary pronation (turning downwards) of one or both hands indicates a weakness in the contralateral arm and is often linked to neurological issues such as lesions in the brain or spinal cord.

The other options focus on different assessments not related to the pronator drift test. Standing on one leg involves balance and lower body strength, whereas correct foot placement during walking evaluates gait and lower extremity function. Walking a straight line assesses balance and coordination without specifically addressing the upper extremities. Thus, option B directly correlates to the assessment of pronator drift and reinforces its specific purpose in clinical examination.