Subjects
The study subjects were 28 university students attending
N University in Cheonan, Chungnam. The study subjects
were randomly assigned to an experimental group of
14 subjects and a control group of 14 subjects. The subjects
were selected from among those who had no particular history
of lung diseases, had no accompanying damage, such
as congenital deformation of the chest, and had not received
any particular treatment to improve pulmonary functions.