When positioning the average adult patient for a lateral projection of the humerus, what should be done?

For a lateral projection of the humerus, the primary goal is to clearly visualize the anatomical structures of the humerus without superimposition. Rotating the arm so that the humeral epicondyles are perpendicular to the image receptor is crucial in achieving this goal. When the epicondyles are positioned perpendicularly, it ensures that the humerus is displayed in its true lateral position, allowing for optimal imaging of the shoulder joint and elbow without overlap of surrounding tissues.

This positioning minimizes distortion and maximizes the clarity and detail of the desired anatomical regions, which is essential for accurate diagnosis and assessment. Proper alignment directly affects the quality of the radiograph, emphasizing the importance of this specific positioning technique.