McGill (2002) suggested the lumbar spine could be modeled as a mast that was supported by stays composed of the supporting muscles, tendons and ligaments. In his model, the spine is a single member supported by stays attached at the top. Using the Direct Stiffness method (Weaver and Gere, 1990), Hodgdon and Putcha (2006) showed that the force in the supported lumbar spine is reduced by 41.5% using a single set of stays. PURPOSE: The purpose of this research is to expand the previous model by calculating the effect of having multiple stays to anchor the spine. METHODS: The expanded model consists of a set of 5 stacked blocks, simulating the vertebrae of the lumbar spine (L1-L5) with guy wires attached to the each of blocks. For the purposes of this analysis, it is assumed the lumbar spine is divided into 5 equal segments and that the displacements in each of the vertebral blocks are proportional to the distance of each segment from the supporting structure (pelvis). No attempt was made to model the effects of the inter-vertebral disks. The model is treated as a truss in which the rotations are neglected. Thus, the only unknown in this model would be the vertical displacement of the top vertebral block (L1). The displacement is a function of the stiffness of the members. Stiffness is calculated from the length, cross-sectional area and modulus of elasticity. All elements of the model were assumed to have equivalent elastic moduli, and cross-sectional areas. The displacements at the top of other vertebrae (L2-L5) are calculated from displacement of the top vertebrae (L1). Following the calculation of the displacement, the force in the lumbar spine was calculated. RESULTS: When expressed as a function of the force, P applied to the top of the spine, the force on the lumbar spine is determined to be 0.363P. This is equivalent to a reduction of 63.7% in the force in the lumbar spine. CONCLUSION: As one might have assumed, increasing the number of supporting stays reduces the force in the spine model. The addition of 4 pairs of stays reduced the force in the spine model an additional 22.2% beyond that provided by one pair of stays. The addition of guy wire pairs decreases the load in the spine, but they are each less effective than the initial pair of stays.