retraction of the chest

retraction of the chest,

the visible sinking in of the soft tissues of the chest between and around the firmer tissue of the cartilaginous and bony ribs, as occurs with increased inspiratory effort or obstruction at some level of the respiratory tract. The extent of retraction depends on the level of an obstruction. Retraction begins in the intercostal spaces. If increased effort is needed to fill the lungs, supraclavicular and infraclavicular retraction may be seen. In infants, sternal retraction occurs with only a slight increase in respiratory effort, the result of the pliability of their chests. Compare intercostal bulging.