Summary: In order to ascertain the significance of spine stability in holding the upright-standing posture after focal muscular disuse atrophy, two optimization-driven approaches were employed to develop kinematics-driven (KD), and stability-based kinematics-driven (SKD) musculoskeletal (MS) models of an adult thoracolumbar. Results of this work showed that for assessment of contralateral muscle impotence in spinal neuromuscular disorders, a stability-based model can make a more realistic prediction compared to the other.