Spinal stability is controlled by two interrelated systems: the spinal column including ligaments and the muscular control system. In addition to these systems, the thoracolumbar fascia (TLF) also interacts with the muscular system to maintain the stability of the spine. The effects of the tensioning of TLF on the spinal stability was investigated using computational analysis. The stability of the spine was analyzed with a three-dimensional finite element model of musculoskeletal system including TLF. The paraspinal muscle activities were calculated based on a hypothesis: the intervertebral disc was assumed to have a transducer function and the muscle is activated according to a sensor driven control mechanism to maintain stability of the lumbar spine. Muscle forces were calculated in examining 40o isometric forward flexed and erect standing postures. As a result, the fascial tension induced a decrease in superficial muscle activity while maintaining the spinal stability.