The present invention relates to devices and methods for assisting breathing in a subject. In one embodiment, the device of the present invention is a splint that can be used to apply negative distending pressure, i.e., outward pull, to one or both of the chest walls and/or the abdomen of a subject. In certain embodiments, the splint comprises an air bladder that can be attached to the skin of the subjects chest and/or abdomen. When the air bladder is inflated, negative distending pressure is applied to the subjects chest and/or abdomen, thereby assisting or promoting respiration. In another embodiment, the splint comprises a piezoelectric material that when activated can provide negative distending pressure to the subjects chest and/or abdomen. In another embodiment, the subject is a neonate. In another embodiment, the inflated air bladder can apply a compressive force on the chest to facilitate expiration, and the removal of secretions in the airways.