While there are many lumbar supports available on the market, it is likely that using a fixed lumbar support will improve comfort. In a study with 31 subjects who did not have back pain, it was reported that sitting motionless for two hours caused low back pain. Sitting tolerance was improved with both a lumbar support that inflated and deflated, and one that had a fixed amount of air. This study also demonstrated that buttock numbness was improved with the use of an air filled lumbar support that inflated and deflated. It was not improved with the lumbar support with a fixed amount of air. Unless you are experiencing buttock numbness, the use of the less expensive lumbar support that had a fixed amount of air seemed to be just as effective overall in decreasing discomfort while sitting for two or more hours.