Although the past 40 years has witnessed a substantial improvement in the acute and chronic management of persons with SCI, mortality remains high during the first year post-injury, and pulmonary complications including pneumonia, lung collapse (atelectasis), respiratory failure, and thromboembolism are the predominant cause. The propensity for pulmonary complications among subjects with SCI stems from paralysis of respiratory muscles. Injury to the cervical and upper thoracic cord significantly compromises function of the diaphragm, intercostal muscles, accessory respiratory muscles, and abdominal muscles. Respiratory muscle dysfunction is manifest as diminution in lung volumes, reduction in maximal static inspiratory and expiratory mouth pressures (MIP and MEP, respectively), and reduction in peak cough pressure and flow. Cough effectiveness is contingent upon both inspiratory and expiratory muscle strength; increasing the pressure-generating capacity of the inspiratory and expiratory muscles in persons with tetraplegia and high paraplegia may, therefore, translate to improved cough effectiveness and reduction in the propensity for atelectasis and, possibly, pneumonia.