A Kinematics Based Testing Protocol for Studying Lumbar Disc Dynamics

The human lumbar intervertebral disc helps stabilize the vertebral bodies by absorbing and distributing loads acting on the spine while maintaining motion across the joint [1]. Current testing methodologies have been designed to study rigid mechanical devices (plates, rods, screws, mechanical joints), and are not suitable for assessing the overall ability of a compliant structure, like the intervertebral disc, to interact with the surrounding tissue structures and restore functionality to the joint [2]. The objective of this study was to develop a kinematics-based testing protocol that prescribes a known kinematics input to a lumbar spinal motion segment unit (MSU) and measures the capacity of the intact MSU to accommodate the motion in terms of compressive and shear loads and range of motion.