Respiratory insufficiencies in subjects with spinal cord injury were studied in five situations: in the air (sitting, dorsal supine position, declivous--15 degrees), and immersed in water up to the neck (sitting, dorsal supine position). Results were compared to those for a group of normal subjects. Total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), vital capacity (VC), forced expiratory volume per second (FEV1) and peak expiratory flow (PEF) were measured and their ratios with theoretical values of each subject were calculated. In handicapped subjects, FEV1 is less significantly diminished than VC and PEF. TLC does not vary, FRC is higher only sitting in the air, RV is more increased. Between situations, FEV1 never varies. In normal subjects, RV does not vary but, sitting in the air, TLC, VC, FRC and PEF increase. In handicapped subjects sitting in the air, VC decreases, RV and FRC increase, TLC and PEF do not vary. In normal and handicapped subjects, the other situations are comparable all together.