An inverse approach to estimating cervical spine disc material properties and disc stress under In vivo load.

This study presents a novel inverse finite element approach to estimate in vivo cervical spine biomechanical function. A physics-constrained optimization framework is used to estimate subject-specific intervertebral disc properties and applied loads that reproduce measured motion. As a proof-of-concept, analysis of a healthy human subject was able to accurately replicate vertebral kinematics within 1 mm on average. Incorporating material heterogeneity significantly improved predictions, while loading assumptions influenced estimated stress distributions. Despite some nonuniqueness in parameter estimation, disc stress patterns remained consistent. As a proof-of-concept with one healthy subject and one flexion motion, this approach shows early promise for noninvasively assessing in vivo tissue properties.