This is the final version of the paper.Accurately replicating the in-vivo loads of the spine is a critical aspect of in-vitro spine testing,
but the complexity of this structure renders this challenging. The design and control capabilities
of multi-axis spine systems vary considerably, and though recommendations have been made
[1, 2], standardized in-vitro methods have not yet been established. As such, it is often difficult to compare different biomechanical studies [3]. The aim of this study was to use international standards [4, 5], and spine testing recommendations [1-3] to develop a standardized protocol for the evaluation of different multi-axis spinal test systems. The protocol was implemented on three six-axis spine systems, and the data used to establish stiffness and phase angle limits. [...]This research was supported by the Catherine Sharpe Foundation, the Enid Linder Foundation, the Higher Education Innovation Fund, and the University of Bath Alumni Fund
