Dependence of the thoracic abdominal ratio of the respiration parameters on body positioning relative to the vector of gravity

: Abdominal and thoracic functional reserves of respiration and level of their involvement in spontaneous breathing were investigated in 10 male volunteers aged 20 to 22 put in horizontal head-down (-7 degrees and -30 degrees) or orthostatic (+70 degrees) position. The thoracic-abdominal functional reserves of respiration dependent on the spatial positioning of the body were found to be the factor that determines magnitude of contribution of the thorax and diaphragm in the breathing volume.