Assessment of intradiscal pressure in a spine with unilateral muscle weakness using kinematics-driven and stability-based kinematics-driven models: is the stability really important?

This study used a finite element (FE) model to determine the spinal loads, and stress distribution in the intervertebral discs (IVDs) of an adult trunk with intact, as well as with the unilaterally weakened muscles under the equivalent loading condition, as an alternative to in vivo loading conditions, which were estimated by our previously-validated trunk musculoskeletal (MS) model of spine [1]. A kinematics-driven (KD) model and a stability-based kinematics-driven (SKD) model, by considering the spine stability, were developed. Results showed more compatibility of SKD model, compared to KD model, to investigate the spinal loads.