Influence of wheelchair positioning aids on the respiratory function of patients with Duchenne muscular dystrophy

The purpose of this study was to determine the influence of wheelchair positioning aids on the respiratory function of patients with Duchenne muscular dystrophy (DMD). Twelve non-ambulatory DMD patients, between 10 to 22 years of age, were evaluated. They were assessed in their adapted wheelchairs and in a standard wheelchair without tilt or reclining. The wheelchairs of the participants possessed adaptations in the backrest and the seat, made according to the specifics of each patient. Minute volume (MV), tidal volume (TV), forced vital capacity (FVC), maximum inspiratory (MIP) and expiratory pressures (MEP) and peak expiratory flow (PEF) were measured. For data analysis we used the paired t-test adopting the significance level of 0.05. The positioning aids resulted in statistically significant better values of all respiratory parameters: MV (8,963.3 and 10,762.5 mL/min; p=0.028), TV (319.1 and 433.6 mL; p=0.005), FVC (1,476.3 and 1,850 mL; p=0.005), MIP (-41.2 and -51.2 cmH2O; p=0.022), MEP (29.6 and 36.7 cmH2O; p=0.004) and PEF (162.1 and 185 L/min; p=0.018). These results may suggest that wheelchair positioning aids can positively influence pulmonary function for non-ambulatory DMD patients.