Effect of body position on pulmonary function.

Pulmonary physical therapy has focused largely on improving ventilation. Bronchial drainage techniques have incorporated body positioning to effect gravity-assisted mucous clearance and to enhance air entry. Body position directly affects ventilation and perfusion matching and arterial oxygen levels. This article briefly describes the role of body positioning on lung function and the clinical implications of this as a treatment priority. The effect of body position on arterial oxygen levels and lung function is discussed for the following positions: erect, lean forward, supine, lateral, prone, head-down tilt, hands and knees, and upside down. The implications of these positions are discussed for both the patient who has lung dysfunction and for the individual who may be at risk for developing pulmonary complications. Research is needed to investigate the principles of therapeutic positioning for optimal gas exchange and lung function. Such work may help to refine pulmonary physical therapy procedures and to identify the role of judicious positioning in a therapeutic exercise regimen.