Which technique involves laying fingers flat against the skin and tapping with the opposite hand?

The technique that involves laying fingers flat against the skin and tapping with the opposite hand is known as percussion. This method is commonly used in clinical settings to produce sound waves and vibrations that can help assess underlying structures in the body, such as organs or tissues. By tapping on the surface of the body, practitioners can gather information about the consistency, size, and position of organs as well as detect any abnormal fluid accumulation or air levels.

In the context of medical evaluations, percussion can be particularly useful for assessing the lungs and abdomen. The sounds produced during percussion vary based on the density of the underlying structures; for instance, a hollow sound may indicate the presence of air, while a dull sound might signify solid organ or fluid presence.

This technique stands out distinctly from other methods such as auscultation, which involves listening to the sounds made by internal organs, palpation, which is the method of using hands to examine the body by feeling its shape, size, and texture, and inspection, which is the visual examination of the body. Each of these techniques serves a unique purpose in a thorough physical examination but percussion specifically focuses on the technique of tapping to elicit sound for further diagnostic information.