In normal subjects, quiet breathing is predominantly abdominal when supine and thoracic when upright, with rapid maneuvers mostly accomplished through rib cage displacement.
Observational (n=81)
In normal subjects, quiet breathing is primarily abdominal when supine and thoracic when upright, while rapid maneuvers rely mostly on rib cage displacement.
By use of the method of Konno and Mead and the respiratory magnetometer, the partition of respired gas volumes into rib cage and diaphragm-abdomen components was accomplished in 81 normal subjects including 32 young and middle-aged men, 29 young and middle-aged women, and 20 elderly men. Studied were isovolume maneuvers and the relaxation configuration over the inspiratory capacity range, quiet tidal breathing, increased amplitudes of slow breathing, rapid inspirations and expirations, and both quiet and forceful phonation. No major differences were noted between men and women or between the young and the elderly during any respiratory acts. During quiet breathing most normal subjects are abdominal breathers when supine and thoracic breathers when upright. Rapid respiratory maneuvers were accomplished mostly through rib cage displacement suggesting that rib cage muscles are capable of more rapid action than diaphragm and abdominal muscles. Data from deep breathing and rapid maneuvers supported the view that abdominal and rib cage muscles often act to optimize the mechanical (length-tension) advantage of the diaphragm.
Sharp et al. (Wed,) conducted a observational in Healthy (normal subjects) (n=81). Respiratory maneuvers and postural changes was evaluated on Partition of respired gas volumes into rib cage and diaphragm-abdomen components. In normal subjects, quiet breathing is predominantly abdominal when supine and thoracic when upright, with rapid maneuvers mostly accomplished through rib cage displacement.