Sensitivity of lumbar spine loading to anatomical parameters

Musculoskeletal simulations of lumbar spine loading rely on a geometrical representation of the anatomy. However, this data has an inherent inaccuracy. This study evaluates the in
uence of dened geometrical parameters on lumbar spine loading utilizing ve parametrized musculoskeletal lumbar spine models for four different postures. The in
uence of the dimensions of vertebral body, disc, posterior parts of the vertebrae as well as the curvature of the lumbar spine were studied. Additionally, simulations with combinations of selected parameters were conducted. Changes in L4/L5 resultant joint force were used as outcome variable. Variations of the vertebral body height, disc height, transverse process width and the curvature of the lumbar spine were the most in
uential. The results indicated that measuring these parameters from X-rays would be most important to morph an existing musculoskeletal lumbar spine model for a subject-specic approach with respect to bone geometry. Furthermore, degeneration processes could lead to computational problems and it is advised that stiffness properties of discs and ligaments should be individualized.