This research project was designed to assess the causal influence of wearing an“air belt”; (pneumatic lumbar support) on the development of muscular strength, hip and back flexibility, and a functional impairment (pain) index. Thirty subjects were randomly selected from a pool of individuals who were diagnosed as having muscular strain/sprain of the lower back by an orthopedic‐neurologic examination. They were graded as mild, moderate, or severe. Subjects in the treatment and control groups were matched according to gender and grade of strain/sprain. Each subject was tested initially, again after I hour, 3 weeks into the program, and finally post‐tested after 6 weeks of therapy or control. Subjects in the treatment group were required to wear the air belt for 1 hour after a pretest, then for 6 hours a day, 5 days a week for the 6 weeks of rehabilitation. Gain scores were analyzed using an analysis of covariance (ANCOVA) with age and pain as the covariates, p≤s 0.05. Muscular strength improved 4.9% after wearing the air belt for 1 hour, 11.5% after 3 weeks, and 16.1% after 6 weeks of use. Since these individuals were functionally impaired as a result of lower back sprain/strain, the air belt does appear to improve substantially the strength otherwise lost due to a lower back injury. The ANCOVA tests for flexibility and pain index gain scores at acute, midchronic, and chronic stages of testing and therapy were all found to be significant. Therefore, it may be concluded that use of the air belt aids in flexibility and lessens the pain perceived in functionally impaired individuals. Subjective assessment of pain decreased by 18% after 1 hour of air belt use, 46% after 3 weeks of use, and 73% after 6 weeks of use. Flexibility improved 35%, 70%, and 93% during the same period. These results indicate how use of the air belt may lessen the pain associated with low‐back injury and may help increase strength and flexibility, thus facilitating a return to normal daily activity.