The predominant mechanism for pulmonary dysfunction in individuals with chronic tetraplegia is respiratory muscle paralysis. This leads to inadequate ventilation and inability to clear secretions placing these patients at a greater risk for the development of respiratory complications. Furthermore, individuals with chronic tetraplegia exhibit baseline increases in airway tone (bronchoconstriction), restoration of normal airway caliber following bronchodilator administration, and non-specific airway hyperresponsiveness (AHR) following inhalation of methacholine, histamine, an aerosolized distilled water. These findings in persons with spinal cord injury (SCI) represent pulmonary features commonly seen in individuals with asthma. Alternatively, airway inflammation may play a role in the obstructive physiology observed in individuals with tetraplegia. In this population, identification of cellular inflammation would confirm the presence of underlying inflammation with a sputum induction. However, this method is hard to perform due to an impaired cough.