Bioinspired Fabric Ligament with Tunable Stiffness for Reproducing 3D Lumbar Spine Kinematics

Lumbar spine ligaments play a critical role in maintaining spine joint stability and structural integrity within segmental biomechanics. However, most existing lumbar spine models and simulators neglect ligament contributions, leading to incomplete or potentially overestimated evaluations of spinal implant performance. Herein, we introduce bioinspired fabric ligaments (BFLs), designed to emulate the hierarchical structure and material properties of natural spine ligaments. By tailoring fabric architecture, strand number, and yarn count, BFLs successfully reproduce the nonlinear force–displacement behavior and tunable stiffness characteristics of natural spine ligaments. Integrating BFLs with three‐dimensional (3D) printed bioinspired vertebrae and intervertebral disc (IVD), we develop a bioinspired lumbar spine system (BLSS). The experimental results demonstrate that the developed BLSS not only restricts the excessive motion of ligament‐deficient models but also replicates physiologically relevant 3D lumbar kinematics. This work establishes a versatile paradigm for ligament‐mimetic design, offering a reliable platform for intervertebral implants evaluation and new opportunities for personalized spinal implants optimization.