Percussion (medicine)

Percussion (medicine)

Percussion is a method of tapping on a surface to determine the underlying structure, and is used in clinical examinations to assess the condition of the thorax or abdomen. It is one of the four methods of clinical examination, together with inspection, palpation and auscultation. It is done with the middle finger of one hand tapping on the middle finger of the other hand using a wrist action. The non striking finger (known as the pleximeter) is placed firmly on the body over tissue. When percussing boney areas such as the clavicle the spleximeter can be omitted and the bone is tapped directly such as when percussing an apical cavitary lung lesion typical of TB.

There are two types of percussion: direct, which uses only one or two fingers, and indirect, which uses the middle/flexor finger. There are four types of percussion sounds: resonant, hyper-resonant, stony dull or dull. A dull sound indicates the presence of a solid mass under the surface. A more resonant sound indicates hollow, air-containing structures. As well as producing different notes which can be heard they also produce different sensations in the pleximeter finger.

Percussion was initially used to distinguish between empty and filled barrels of liquor, and Dr. Leopold Auenbrugger introduced the technique to medicine.