The objective of this study was to evaluate the adequacy of data supporting the use of back belts to reduce work related back injuries in healthy, previously uninjured workers. The study included a review of the published scientific literature describing laboratory based research on biomechanical, physiological, and psychophysical aspects, variables, or parameters pertaining to back belt use. The NIOSH Back Belt Working Group concluded that there are insufficient data to indicate that typical industrial type back belts significantly reduce the biomechanical loading of the trunk during manual lifting. No studies provided conclusive evidence that actual trunk muscle forces, predicted spinal compression, or shear forces were significantly reduced by wearing a back belt. A number of studies suggest that abdominal and back extensor muscle strength changes with prolonged back belt use. Long term use of back supports may decrease abdominal muscle tone, thereby increasing the likelihood of back injury if the user discontinued use of the back belt. The possibility that a worker may lift heavier loads while using the back belt is real and may resulted in injury. The Working Group recommended that the most effective means of minimizing the likelihood of back injury is to develop and implement a comprehensive ergonomics program.