Breathlessness and exercise in spinal cord injury.

After spinal cord injury (SCI), breathlessness during daily activities is common. In 308 individuals with SCI, the authors measured pulmonary function and administered a survey regarding health status, participation in wheelchair athletics, and breathlessness during different activities. The following questions were included: A. Are you troubled by shortness of breath when hurrying on the level or going up a slight hill?; B. Do you have to go slower than people of your own age on the level because of breathlessness?; C. Do you ever have to stop for breath when going at your own pace on the level?; and D. Do you ever have to stop for breath after going about 100 yards on the level? The analysis was restricted to 183 subjects with neurologically motor complete or incomplete SCI who, to get around, used hand-propelled wheelchairs more than 50% of the time. Of these, 56 (31%) reported breathlessness during some types of activities. Subjects with neurologically motor complete cervical or high thoracic SCI (T-6 and above) were more likely to report breathlessness than others (39% compared with 25%, p = .039). Among wheelchair athletes, the prevalence of breathlessness was 8/49 (16%) versus 48/134 (36%) for non-athletes (p = .011). Adjusting for smoking, neurological level, and history of obstructive lung disease, non-athletes were 2.3 times more likely to report breathlessness than athletes were (p = .049 to .075, depending on regression model). This relationship persisted when adjusted for percent predicted forced expiratory volume (FEV1) and maximal expiratory and inspiratory pressures. Therefore in SCI, wheelchair athletes are less likely to report breathlessness than non-athletes, but the mechanism does not appear to be improvement in respiratory muscle performance or pulmonary function.