Relation between corset use and lung function postural variation in spinal cord injury.

Corsets are widely used to improve trunk stability in patients with spinal cord injury (SCI) and can improve respiratory function. The aim of the present study was to identify predictors of respiratory benefits from wearing a corset in SCI patients. In a prospective observational study, respiratory function was tested in the supine and upright seated position with and without a corset in 36 SCI patients who regularly used a corset. SCI patients who no longer used a corset were matched to users on sex, injury level and severity. Vital capacity (VC) did not differ between users and nonusers in the supine position. In users, contrary to nonusers, VC increased significantly in the supine position compared to the seated position (increase of 0.43+/-0.39 versus -0.05+/-0.32 L in nonusers; p<0.0001). Corset use was associated with a significant VC increase in the upright position (2.13+/-0.71 L without versus 2.41+/-0.69 L with the corset; p<0.001). The VC increase with the corset in the upright position correlated significantly with the VC increase induced by being supine, compared to sitting without the corset. The VC increase induced in SCI patients by lying supine may predict the effects of wearing a corset. The long-term effects of corset use should be evaluated.