Balloon Blowing Breathing Exercise in School-age Children With Asthma.

Respiratory muscle strength was assessed by measuring Maximal Inspiratory Pressure (MIP) and Maximal Expiratory Pressure (MEP) in cmH2O. The participants were in a sitting position using a portable handheld mouth pressure meter (i.e., MicroRPM) with a nose clip. For the MIP measurement, the participants were asked to exhale until they felt no air remaining in their lungs (starting with the functional residual capacity [FRC] point), then held the device on their mouth and inhaled forcefully for 1-2 seconds. For the MEP measurement, the participants were asked to inhale until their lungs were completely filled with air (starting with the total lung capacity [TLC] point), then they kept the device on their mouth and exhaled forcefully for 1-2 seconds.

Asthma control was measured by Childhood Asthma Control Test (C - ACT) questionnaire. The range of C-ACT scores is 0 to 27 (27 = totally controlled, 20-26 = well controlled, <26 = insufficiently controlled)

FVC is the total volume of air that can be exhaled during a maximal forced expiration effort. The participants were asked to wear a nose clip while sitting on a chair, and the researcher gave the participants the step-by-step protocol to prevent an incorrect maneuver. For the FVC maneuver, three cycles of slow normal breathing were performed before demonstrating forced inspiration and expiration. FVC is measured in liters.

FEV1 is the volume of air exhaled in the first second under force after a maximal inhalation. The participants were asked to wear a nose clip while sitting on a chair, and the researcher gave the participants the step-by-step protocol to prevent an incorrect maneuver. For the FVC maneuver, three cycles of slow normal breathing were performed before demonstrating forced inspiration and expiration. FEV1 was showed in liters.

It represents the proportion of a person's vital capacity that they are able to expire in the first second of forced expiration (FEV1) to the full, forced vital capacity (FVC). The participants were asked to wear a nose clip while sitting on a chair, and the researcher gave the participants the step-by-step protocol to prevent an incorrect maneuver. For the FVC maneuver, three cycles of slow normal breathing were performed before demonstrating forced inspiration and expiration. FEV1/FVC was showed in percentage.

PEF is the amount and rate of air that can be forcefully breathed out of the lungs. The participants were asked to wear a nose clip while sitting on a chair, and the researcher gave the participants the step-by-step protocol to prevent an incorrect maneuver. For the FVC maneuver, three cycles of slow normal breathing were performed before demonstrating forced inspiration and expiration. PEF is measured in liters/seconds.

FEF25-75% is the average flow from the point at which 25 percent of the FVC has been exhaled to the point at which 75 percent of the FVC has been exhaled. The participants were asked to wear a nose clip while sitting on a chair, and the researcher gave the participants the step-by-step protocol to prevent an incorrect maneuver. For the FVC maneuver, three cycles of slow normal breathing were performed before demonstrating forced inspiration and expiration. FEF25-75% is forced expiratory flow over the middle one half of the FVC; the average flow from the point at which 25 percent of the FVC has been exhaled to the point at which 75 percent of the FVC has been exhaled. FEF25-75% is measured in liters/seconds.

The participants were asked to inhale and exhale quickly and forcefully for 10 seconds. Maximal Voluntary Ventilation (MVV) were measured in liters/minutes.