The flow-volume loop during glossopharyngeal breathing.

The flow-volume loops of three patients with chronic poliomyelitis were examined during glossopharyngeal breathing and compared with those during forced vital capacity maneuvers using only chest wall muscles. Peak expiratory flow rates and vital capacities were greater in all subjects after inspiration using glossopharyngeal breathing. During glossopharyngeal breathing, there was a progressive fall in the inspiratory flow rate and volume of each stroke as pulmonary volume increased.