To obtain a true AP projection of the forearm, the hand should be _____.

To obtain a true anteroposterior (AP) projection of the forearm, the hand should be supinated. Supination means that the palm is facing upward or forward when the arm is in a resting position at the side of the body. In this position, the radius and ulna are parallel to each other, which is essential for accurately visualizing the bony structures of the forearm without superimposition.

When the hand is supinated during the AP projection, it allows the x-ray beam to pass perpendicular to the forearm, ensuring that both the elbow and wrist joints are included while minimizing distortion of anatomical structures. This positioning is crucial for diagnostic imaging, as it helps to demonstrate any fractures or other abnormalities clearly.

Positioning the hand in any other orientation, such as pronation or neutral, would lead to some degree of superimposition of the radius and ulna, possibly obscuring critical details in the imaging. Extending the hand alone does not address the orientation necessary for a true AP projection, which is why supination is the optimal choice for this imaging technique.