(normally 3cm to 5 cm).
a) Patient seated takes a deep breath and holds it.
b) Percuss the back downward until a definite change in the PER note is found.
Indicates the lower level of diaphragmatic excursion.
c) Repeat step b with the Patient holding his/her breath in full expiration
(breath out as much as possible). Indicates the upper level of diaphragmatic excursion.
d) The Diaphragmatic excursion is the distance between the two levels.
High diaphragm: Pregnancy, ascites, increased intra-abdominal pressure.
Low/fixed diaphragm: Emphysema.