Low back pain commonly reduces tolerance for the prolonged sitting required by many occupations and routine daily activities. In order to provide lumbar lordotic continuous passive motion (CPM), a pneumatic device was developed. This device includes a lumbar support bladder, which is cyclically inflated and deflated by a pump and valve system. This system is controlled by a timer and by pressure feedback from the bladder. The user selects cycle duration and peak support pressure. Using a simulated automobile setting, the first part of this study demonstrated that CPM produces lumbar lordotic motion and improved comfort for subjects without histories of low back pain. In the second part of the study, 28 people with chronic low back pain reported greater comfort using CPM during their routine motor vehicle operation. Further research is needed to determine whether this promising new strategy against low back pain can reduce occupational disability due to sitting intolerance.