<unk> is a method of tapping on a surface to determine the underlying structures, 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, auscultation, and inquiry. It is done with the middle finger of one hand tapping on the middle finger of the other hand using a wrist action. The nonstriking finger (known as the pleximeter) is placed firmly on the body over tissue. When<unk> g boney areas such as the clavicle, the pleximeter can be omitted and the bone is tapped directly such as when<unk> g an apical cavitary lung lesion typical of TB. There are two types of<unk>  direct, which uses only one or two fingers, and indirect, which uses the middle/flexor finger. There are four types of<unk> 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.<unk> was at first used to distinguish between empty and filled barrels of liquor, and Dr. Leopold Auenbrugger is said to be the person who introduced the technique to modern medicine, although this method was used by Avicenna about 1000 years before that for medical practice such as using<unk> over the stomach to show how full it is, and to distinguish between ascites and tympanites.
Percussion 
Pulse 
Pulse
Concussion
Sound 
Triangle of auscultation
Capillary refill
Cough reflex